NTSB Safety Research Report - Drug Use Trends in Aviation 2018-2022 (SRR-26-01)

2018- 2022 Update to Drug Use Trends in

Aviation

Summary

This safety research report provides an update concerning drug presence

identified by toxicology testing of flying pilots who were fatally injured in United S tates

civil aviation accidents during the years 2018 –2022.

This research update showed a continued increase in overall drug presence

among fatally injured pilots when compared with the results of previous National

Transportation Safety Board (NTSB) reports that examined the periods 2013–2017

and 1990–2012.1 More than half ( 52.8%) of fatally injured pilots tested positive for at

least one drug, and more than a quarter (27.7%) te sted positive for two or more

drugs. This report, like the previous two, did not attempt to use information about

drug presence to infer whether a pilot was impaired. Rather, we are reporting on the

presence of drugs, some of which have the potential to cause impairment or are used to treat potentially impairing conditions.

Among the four drug types analyzed in this research update , two increased

and two decreased compared with the NTSB’s 2020 report . The largest increase was

in illicit drugs, which were detected in 7.4 % of fatally injured pilots for the 5 -year period

examined , a 2.4 percentage point increase over the previous 5- year period. This

increase was primarily due to an increased prevalence in delta -9-tetrahydrocannabinol ,

the primary psychoactive chemical in marijuana. Potentially impairing drugs, a broader category that included illicit drugs as well as prescription and over- the-counter

drugs that could diminish a pilot ’s cognitive or psychomotor performance, increased

0.6 percentage points to 28.6%. Drugs used to treat potentially impairing conditions decreased 1.6 percenta ge points to 1 3.5% , and controlled substances decreased

3.2 percentage points to 6. 9%.

With regard to categories of drugs, the most commonly found were

cardiovascular drugs, sedating antihistamines, nonsedating over -the-counter drugs,

cholesterol-lowering drugs, prostate/erectile dysfunction drugs , and illicit drugs . A

1 NTSB . 2014. Drug Use Trends in Aviation: Assessing the Risk of Pilot Impairment . SS- 14/01.

NTSB. 2020. 2013 –2017 Update to Drug Use Trends in Aviation . SS- 20/01. March 25, 2026 Safety Research Report SR R-26-01

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ii new drug category was introduced in this research update : US Food and Drug

Administration u napproved d rugs, which was present in 0.8% of fatally injured pilots.

Drug prevalence was relat ed to several factors , including age, flight

operations , and certification . The prevalence of potentially impairing drugs and drugs

indicating potentially impairing conditions were more common in older pilots. Drug

prevalence of all types was lower among pilots conducting Title 14 Code of Federal

Regulations Part 135 operations compared with those conducting general aviation

operations . With respect to certification , drug prevalence was lowest among pilots

holding air line transport pilot or commercial pilot certificates compared with those

holding private, sport, or student pilot certificates , or those with no pilot certificate .

Similarly, drug prevalence was lower among pilots whose medical certificate was still

within the duration limits of a third -class certificate compared with those with expired

or no medical certificates.

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1 1 Introduction

This safety research report provides an update concerning drug presence

identified by toxicology testing of flying pilots who were fatally injured in United States

civil aviation accidents during the years 2018 –2022.1 The report also examines factors

associated with the presence of certain drug types and show s trends in drug

presence in fatally injured pilots since 1990.

1.1 Background

The National Transportation Safety Board ( NTSB ) published two previous

reports on drug presence in fatally injured pilots : one in 2014, which presented data

concerning 1990 –2012, and one in 2020, which provided a 5 -year update for

2013–2017 (NTSB 2014, 2020a).2 Those reports, like this report , did not attempt to

use information about drug presence to infer whether a pilot was impaired.3 Rather,

they report ed on the presence of drugs, some of which have the potential to cause

impairment or are used to treat potentially impairing conditions.

1.2 Recommendation History

The NTSB has made more than 50 safety recommendations since 1974

concerning alcohol and other drug use in aviation.4 The recommendations have

focused on several topics including :

1 Visit ntsb.gov to find additional information in the public docket for this National

Transportation Safety Board ( NTSB ) report (case number DCA24SS011 ). Use th e CAROL Query to

search safety recommendations and investigations.

2 The NTSB published two additional research reports concerning alcohol and other drug

involvement in fatal general aviation accidents (NTSB 1992, 1984). However, the research described in

those reports used a different methodology than that used for the research the NTSB has conducted

since 2014, including in this research update (NTSB 2020a, 2014) . Consequently, the results are not

comparable.

3 During the period analyzed for this report ( 2018– 2022) , 25 out of 1,126 accidents (2.2%)

included impairment from drug effects in the probable cause. In general, the NTSB includes

impairment f rom drug effects in the probable cause when there is sufficient case -specific evidence that

effects of drugs likely contributed to the accident occurrence or outcome. Potential drug -related

impairment may be identified in an investigation without being included in the probable cause. Also,

some drugs may indicate potentially impairing conditions.

4 A full list of the recommendations and their statuses is available in the public docket for this

NTSB report (case number DCA24SS011) .

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2 • conducting research to better understand trends in drug use ;

• expanding, improving, and standardizing drug toxicology testing ;

• improving p reemployment and postaccident drug testing ;

• increasing e ducation for pilots, healthcare providers , and medical

examiners about the effects of alcohol and other drugs ; and

• ensuring t reatment for alcohol and drug use disorders .

The majority of the recommendations were classified Closed —Acceptable

Action based on the responsive actions of recommendation recipients . Currently,

there is one open safety recommendation that was issued in the NTSB’s 2020 updat e

(NTSB 2020a). In that report, the NTSB concluded that increasing evidence of

marijuana use by pi lots indicated a safety hazard that had not been effectively

addressed , and we recommended that the Federal Aviation Administration (FAA):5

Revise the Aeronautical Information Manual and the Pilot ’s Handbook of

Aeronautical Knowledge , FAA-H -8083-25B , to explicitly state marijuana ’s

classification as an illicit drug per federal law and, thus, its prohibited

use by airmen . (A-20- 12)6

In July 2023, the FAA updated the Pilot ’s Handbook of Aeronautical Knowledge

(FAA 2023a ). The updated handbook includes the following text:

Even though the [US] Drug Enforcement Administration (DEA) defines

marijuana as a Schedule I drug on its controlled substances list, states

have taken st eps to allow the possession, sale, and use of marijuana

withing [sic] their border [sic]. The FAA has stated, “ Marijuana is an illicit

drug per federal law and its use by airmen is prohibited. ”

In July 2024, the NTSB informed the FAA that S afety R ecommendation A -20-12

was classified Open —Acceptable Response pending a similar update to the

Aeronautical Information Manual .7 In August 2025, the FAA published a revis ion to

5 The finding is discussed on page 14 and listed on page 17 of the 2020 research update

(NTSB 202 0a).

6 (a) Safety Recommendation A -20-12 was classified Open —Acceptable Response on July 11,

2024. (b) Airmen refers to pilots as well as individuals who maintain and repair aircraft, air traffic

controllers , and others (see Title 49 United States Cod e, section 40102).

7 See the NTSB correspondence concerning Safety Recommendation A -20-12.

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3 the Aeronautical Information Manual , which d id not include any discussion of

marijuana (FAA 2025).8

8 The NTSB contacted the FAA via email on December 2, 2025, about this issue and received a

response via email on December 2 , 2025, stating that information about marijuana was unintentionally

left out of the revision and that the manual would be updated to include the recommended text in

August 2026.

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4 2 Methodology

This safety research report generally followed the methodology used in the

two previous NTSB report s on the topic , including how drugs were classified and how

pilot toxicology data were linked to NTSB aviation accident data (NTSB 2020a , 2014).

2.1 Drug Testing , Identification, and Classification

2.1.1 Drug Testing

The drug toxicology data used in this research update were provided by the

FAA Forensic Sciences Laboratory at the Civil Aerospace Medical Institute . After a

fatal civil aviation accident in the U nited S tates , the Forensic Sciences Laboratory

routinely conducts comprehensive tox icology test ing on biological specimens

collected from fatally injured pilots . The Forensic Sciences Laboratory ’s testing can

identify about 1,000 substances.9

2.1.2 Drug Identification

Upon identifying a positive toxicology finding in a pilot’s specimen , several

steps were taken to do the following:

• prevent overcounting of multiple positive results associated with one

drug ,

• determine that detected drugs were used by pilots before the accident ,

and

• identify only drugs that had the potential to affect a pilot ’s performance

during the accident flight.10

In some cases, the FAA Forensic Sciences Laboratory tests for the original drug

and one or more metabolites of that drug. The fact that some metabolites are also marketed as separate drugs complicates the interpretation of positive toxicology

findings. To prevent overcounting the number of drugs identified, an equivalency

9 For more information about the FAA Forensic Sciences Laboratory, its methods, and the

drug s it tests for, see the web page of the FAA ’s Forensic Sciences Section . In 2016, the Forensic

Sciences Laboratory added instrumentation that allowed for an analytical technique known as liquid

chromatography with tandem mass spectrometry , which would have improved the sensitivity of some

of the drug testing , potentially leading to more positive results .

10 These steps were the same as those followed in the NTSB 2020 and 20 14 reports (NTSB

2020a, 2014) .

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5 table was used to equate the original drugs with their identified metabolites, and any

duplicates were removed.11

Additionally, in cases where pilots tested positive for drugs commonly

administered after an accident, such as those used for resuscitation or emergency

medical treatment , NTSB medical officers conducted case reviews to identify and

remove drugs that were unlikely to have been used before the accident .12 Ethanol

and other alcohols were also excluded because they can be produced by microbial

action in body tissues and fluids after death.13

Finally, drugs found only in urine were excluded, consistent with the methods

of previous NTSB reports (NTSB 2020a, 2014).14

2.1.3 Drug Classification

2.1.3.1 Drug Types

Drugs were classified into the following four broad types :

1. potentially impairing drugs,

2. drugs used to treat potentially impairing conditions,

3. controlled substances, and

4. illicit drugs.

11 The equivalency table is available in the public docket for this NTSB report (case number

DCA24SS011). Two drugs , levamisole and phenylpropanolamine , were excluded from analysis. These

drugs are impurities in certain illicit stimulants and were only found in conjunction with those

stimulants .

12 Case reviews were done when atracurium, atropine, etomidate, fentanyl, ketamine,

laudanosine, lidocaine, midazolam, norfentanyl, norketamine, or propofol were present .

13 Postmortem alcohol production depends on multiple variables but generally is made more

likely by extensive injuries or delayed recovery of remains (Kugelberg and Jones 2007).

14 Previous NTSB reports excluded results from urine specimens because drugs found only in

urine after death are not indicative of a pilot’s impairment or adverse effects while flying (NTSB 202 0a,

2014) . Drug results in other tested specimen types sometimes may provide at least limited information

about impairment likelihood. This report did not exclude any specimen types other than urine , nor was

any attempt made to discern whether specimen types were useful for determining impairment on a

case -by-case basis. This report and the associated previous NTSB report s did not determine

impairment .

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6 Some drugs were classified in more than one type, and some did not fall into any of

these classifications. See appendix A for a complete list of every drug identified and

how it was classified.

Potentially Impairing Drugs: This drug type included p rescription and

over -the-counter (OTC) drugs that, with typical therapeutic use, produce typical

effects that could diminish a pilot ’s cognitive or psychomotor performance. Illicit

drugs and controlled substances were also included. Additionally , certain drugs not

currently approved by the US Food and Drug Administration (FDA ) have typical

psychoactive effects known to adversely affect cognitive and psychomotor

performance . These drugs were also classified as potentially impairing.15

Drugs Used to Treat Potentially Impairing Conditions : This drug type refers

to drugs used to treat medical conditions that may affect a person ’s performance . A

conservative approach was taken to identify the drugs in this category , with attention

to maintaining consistent classification with previous NTSB reports for ease of

longitudinal comparison (NTSB 2020a, 2014). For example, although cold or allergy

symptoms may impair performance , antihistamines and decongestants were not

classified as indicat ing a potentially impairing condition. D rugs classified as indicating

a potentially impairing condition included drugs used to treat depression, anxiety,

seizures, migraines, and other neuropsychiatric conditions, as well as drugs used to

treat nausea and vertigo, and sedating pain drugs. Among the cardiovascular drugs,

only those primarily used to treat arrhythmias were classified as indicating a

potentially impairing condition . Blood thinners and diabetes medications were not

automatically classified as indi cating a potentially impairing condition under the

conservative assumptions of previous NTSB reports, and this was not changed (NTSB

2020a, 2014).16 Although addiction to or withdrawal from illicit drugs may be

impairing, illicit drugs (not used therapeutically ) were not classified as indicating a

potentially impairing condition . Although individuals may sometimes use FDA

unapproved drugs in an attempt to treat symptoms of a medical condition, these

drugs also were not classified as indicating a potentially impairing condition . No

attempt was made to ascertain anything about the presence, degree, or success of

treating any condition, and no attempt was made to ascertain if there was impairment at the time of the accident.

15 Section 2.1. 3.2 of this report describes the specific drugs within the FDA unapproved drug

category and whether they were considered potentially impairing.

16 A few drug classification changes were made to resolve minor inconsistencies within

categories or between previous report iterations; these changes are noted in appendix A.

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7 Controlled Substances: All drugs that are federally regulated are divided into

five s chedules under the Controlled Substances Act based on the drug ’s accepted

medical use and potential for abuse or dependence .17 Drugs in Schedules II through

V are available for medical use and for this research update were categorized as

controlled substances. Examples include opioid s used for pain treatment and

benzodiazepines used to treat anxiety . All of the identified controlled substances

were also classified as potentially impairing drugs . Illicit drugs (not used

therapeutically ), although controlled substances, were excluded from such

classification for purposes of this report to keep the report’s discussion of controlled

substances separate from the discussion of illi cit drugs.

Illicit Drugs: This drug type , which also was a drug category as discussed in

section 2.1.3.2 of this report , included S chedule I drugs that, according to the DEA ,

have “ no currently accepted medical use and a high potential for abuse. ”18 Their use

can lead to psychological or physical dependence. Examples include heroin and

delta -9-tetrahydrocannabinol (delta -9-THC), the primary psychoactive chemical in

marijuana. In this research update , three Schedule II drugs —amphetamine, cocaine,

and methamphetamine —and one Schedule III drug —ketamine —were also defined as

illicit when evidence indicated likely nonmedicinal use .19 This research update did not

otherwise evaluate whether drugs had been used illicitly. Illicit drugs were also

classified as potentially impairing drugs .

Importantly, pilots should not infer that they may safely or legally use a drug

based on its classification in this report. Even drugs not classified under any of the

above types may have impairing effects, may be used to treat impairing conditions,

or may carry restrictions on use by pilots under FAA policy.

2.1.3.2 Drug Categories

In addition to the four broad types described above, a second classification

scheme categorized identified drugs based on their chemical structure, typical use,

or effects into the following categories:20

17 See Title 21 United States Code , section 811 and section 812.

18 See the DEA’s “Drug Scheduling “ web page.

19 For amphetamine and methamphetamine, if there were positive results for other Schedule I

drugs, metabolites or forms of the drug present indicating an illicit source, or higher blood levels of

the drug than would be expected for medical use, the findings were classified as illicit. For cocaine and

ketamine, if there was no evidence that the drug was administered as a part of postaccident treatment

and no evidence of prescribed use, it was classified as illicit.

20 The categories are defined in detail in a ppendix B.

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8 • antidepressants

• anti-infective drugs

• anti-seizure drugs

• benzodiazepines

• blood thinners

• cardiovascular drugs

• cholestero l-lowering drugs

• diet aids

• emphysema and asthma drugs

• FDA unapproved drugs

• illicit drugs

• migraine drugs

• nausea and vertigo drugs

• nonsedating OTC drugs

• nonsedating pain relievers

• oral diabetes drugs

• other drugs

• other neurologic drugs

• other psychotropic drugs

• prescription sleep aids

• prostate/erectile dysfunction drugs

• sedating antihistamines

• sedating pain relievers

The drug categories used in this research update are the s ame as those used

in our 2020 update except for the category of FDA u napproved drugs (NTSB 2020a).

This category consists of drugs that have neither been identified as federally

controlled substances nor are medications approved by the FDA for therapeutic use .

In the dataset used for this update , the category of FDA unapproved drugs included

cannabidiol (CBD), d elta-8-THC, m itragynine , and yohimbine , which are defined as

follows :

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9 • CBD is a chemical in cannabis plant s that does not typically cause

impairment based on objective measures of performance and is not

specifically disqualifying for FAA medical certification.21

• Delta-8-THC is a cannabinoid that is usually chemically manufactured

from CBD , has psychoactive and intoxicating effects , and is potentially

impairing .

• Mitragynine is the main psychoactive chemical in the herbal product

kratom, which has stimulant effects at low doses and sedative effects at

high doses and is considered potentially impairing.

• Yohimbine is a chemical found in the bark of the yohimbe tree and certain other plants and is marketed as an erectile dysfunction drug. It is

not typically impairing , although adverse side effects may occur .

21 A pharmacologically pure form of CBD was first approved by the FDA in 2018 for treatment

of specific uncommon types of seizures. Other CBD products, which are widely available for purchase,

are not FDA approved. For purposes of this report, detected CBD wa s assumed to represent use of

one of those products.

22 In the NTSB 2020 update , yohimbine was included in the “prostate/erectile dysfunction

drugs ” category (NTSB 2020a) .

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10 3 Results

3.1 Pilot Demographics

Over the 5 years between 2018 and 2022, 984 flying pilots were fatally injured in

aviation accidents in the United States.23 Of th ose, 930 pilots (94 .5%) had available

toxicology test results and were included in th is research update .24 The average age of

the pilots was 57 years, 1 year older than the average age from the last 5-year period

analyzed . The majority of the pilots , 906 (97.4%), were male and 24 ( 2.6%) were female.

As shown in figure 1, the highest pilot certificate held by most pilots was private

(43.3%), followed by commercial (3 1.7%) and airline transport pilot (ATP) (15.6%).

Figure 1. Distribution of pilots by highest pilot certificate held , 2018– 2022.

23 For cases involving multi -pilot crews or with more than one pilot on board, only the pilot

identified in the NTSB aviation accident records as the pilot presumed to be flying the accident aircraft

was included in the dataset used for this research update . If no pilot could be identified as the flying

pilot, none were included.

24 All results in this safety research report are reflective only of the pilots included in the dataset

used for this update.

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11 In terms of flight operations, 894 pilots (96.1%) were conducting general

aviation operations, 3 4 pilots ( 3.7%) were flying under Title 14 Code of Federal

Regulations (CFR ) Part 135, 1 pilot ( 0.1%) was operating under 14 CFR Part 121

scheduled airline operations, and 1 pilot (0.1%) was operating under Canadian

regulations.25

With respect to medical certificates, pilots were classified according to whether

they had a medical certificate that was still within the duration limits of a third -class

certificate at the time of the accident.26 There were 644 pilots (69.2%) that met that

definition. There were 283 pilots (30.4%) without a medical certificate and 1 pilot

(0.1%) whose medical certificate was unknown . Additionally, 2 pilots (0.2%) were

Canadian and held Canadian medical certificates.

Within the group of 644 pilots whose medical certificate was within the

duration limit s of a third -class certificate , 119 (18.5%) had been issued a first -class

certificate, 254 (39.4%) had been issued a se cond -class certificate, and 271 (42.1%)

had been issued a third-class certificate. Pilots without a medical certificate may have

been performing operations not requiring medical certificat ion or may have been

illegally performing operations requiring medical certificat ion.27

25 The accident involved a Canadian -registered airplane that departed from an airport in

Ontario, Canada, bound for Prince Edward Island, Canada, and crashed in Greenville, Maine . See

NTSB ’s Aviation Investigation Final Report , Greenville, Maine , July 30, 2018 (case number

ERA18FA206) (NTSB 2020b ).

26 A pilot was classified as having a medical certificate if the pilot’s most recent FAA medical

certificate was not known to have been invalid (expired for all classes, suspended, or revoked) at the

time of the accident. To help identify certificates that had expired for all classes, a calculation was

applied based on the date of the last aviation medical examination, the pilot’s age as of that date, and the accident date. Additionally, accident dates were checked against any documented time limitations on th e most recent certificate. For each pilot who was classified as having a medical certificate, the

most recently issued medical certificate was classified by its issued class. For example, a first -class

certificate that had expired for operations requiring first - and second -class certification, but that

remained valid for operations requiring third- class certification, was classified as a first -class certificate.

This research update did not evaluate whether pilots held valid medical certification for the operation

being performed, due to the complexity of this determination.

27 Not all piloting operations require FAA medical certification. For example, pilots exercising

sport pilot privileges, pilots flying under the provisions of BasicMed , and pilots operating balloons,

gliders, and ultralight vehicles do not require medical certification if other applicable requirements are met. For more information on medical certification requirements , see 14 CFR 61.23(a).

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12 3.2 Drug Prevalence Trends

Table 1 and f igure 2 show that the trend for overall drug prevalence among

fatally injured pilots has continued to increase since the original period (1990–2012)

analyzed in NTSB’s 2014 report (NTSB 2014). For the 2018–2022 period, 52.8% of all fatally injured pilots tested positive for at least one drug, 27.7% tested positive for

more than one drug, and 14.3% tested positive for more than two drugs .

Table 1. Overall drug prevalence among pilots by time period .

Number of

Drug Findings 1990– 1997 1998– 2002 2003– 2007 2008– 2012 2013– 2017 2018– 2022

At Least 1 Positive

Drug Finding 17.1% 26.0% 30.2% 37.3% 47.1% 52.8%

More Than 1 Positive

Drug Finding 5.6% 8.7% 11.4% 16.8% 24.4% 27.7%

More Than 2 Positive

Drug Findings 2.2% 3.6% 5.3% 7.3% 12.3% 14.3%

Figure 2. Percent of pilots with positive toxicology findings for all drugs, 1990 –2022.

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13 Table 2 and f igure 3 depict trends in drug prevalence by drug type. For t he

2018–2022 period, two types of drugs increased in prevalence since the 2013–2017

period. Potentially impairing drug prevalence increased from 28.0% to 28.6% and

illicit drug prevalence increased from 5.0% to 7.4%. By contrast, since the 2013–2017

period, the prevalence of drugs used to treat potentially impairing conditions and

controlled substances decreased from 15.1% to 13.5% and from 10.1% to 6.9%,

respectively.

Table 2. Drug prevalence by drug type among pilots by time period.

Drug Type 1990– 1997 1998– 2002 2003– 2007 2008– 2012 2013– 2017 2018– 2022

Potentially Impairing

Drugs 11.1% 17.7% 18.6% 23.0% 28.0% 28.6%

Potentially Impairing

Condition s 4.1% 8.1% 9.4% 11.6% 15.1% 13.5%

Controlled Substances 2.8% 4.0% 4.0% 7.6% 10.1% 6.9%

Illicit Drugs 2.3% 2.9% 2.9% 3.8% 5.0% 7.4%

Figure 3. Percen t of pilots with positive toxicology findings by drug type, 1990 –2022.

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14 Table 3 shows trends in drug prevalence by drug category. For the 2018–2022

period, the most commonly found drug categories were, in order: cardiovascular

drugs, sedating antihistamines, non sedating OTC drugs, cholesterol -lowering drugs,

prostate/erectile dysfunction drugs, and illicit drugs. Two of those categories —sedating

antihistamines and illicit drugs —consisted of drugs that are also considered

potentially impairing. Within the category of sedating antihistamines, the most

commonly found was diphenhydramine (an active ingredient in many allergy and

nighttime cold and flu products ), accounting for about half of all sedating

antihistamine detections and present in 6.7% of all fatally injured pilots . The

second -most common sedating antihistamine was cetirizine , account ing for about

one in four sedating antihistamine detections and present in 3.7% of all fatally injured

pilots.28 For illicit drugs, the most commonly found was delta -9-THC, accounting for

nearly three-quarters of illicit drug detections and present in 6. 1% of all fatally injured

pilots .

28 Cetirizine is not a first -generation sedating antihistamine, but it has more sedating potential

than other second -generation antihistamines, and it is listed as sedating in FAA guidance to pilots and

aviation medical examiners (FAA 2024, 2022) .

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15 Table 3. Percent of pilots with positive toxicology findings by drug category, 1990 –2022.

Drug Category 1990– 1997 1998– 2002 2003– 2007 2008– 2012 2013– 2017 2018– 2022

Cardiovascular drugs 2.4% 4.2% 8.0% 12.4% 18.2% 17.0%

Sedating antihistamines 5.6% 8.2% 8.3% 9.9% 11.9% 12.7%

Nonsedating OTC drugs 4.6% 6.8% 6.2% 7.3% 7.0% 10.6%

Cholesterol- lowering drugs 0.1% 0.0% 0.0% 2.0% 6.9% 9.7%

Prostate/erectile

dysfunction drugs 0.0% 0.2% 0.8% 1.6% 3.5% 7.5%

Illicit drugs 2.3% 2.9% 2.9% 3.8% 4.9% 7.4%

Antidepressants 1.0% 4.5% 5.8% 5.3% 7.1% 6.2%

Nonsedating pain relievers 0.6% 0.1% 2.6% 1.7% 2.6% 5.3%

Sedating pain relievers 1.0% 2.4% 2.6% 4.4% 5.3% 3.1%

Anti-seizure drugs 0.7% 0.1% 0.6% 1.0% 1.2% 2.7%

Blood thinners 1.6% 0.5% 0.1% 1.3% 1.4% 2.6%

Benzodiazepines 1.3% 1.1% 0.8% 2.0% 3.0% 2.2%

Other drugs 0.2% 1.5% 2.1% 1.9% 1.3% 2.2%

Other psychotropic drugs 0.2% 0.3% 0.7% 0.8% 1.5% 1.8%

Prescription sleep aids 0.0% 0.0% 0.2% 1.5% 2.6% 1.4%

Nausea and vertigo drugs 0.2% 0.1% 0.3% 0.3% 0.3% 1.1%

Oral diabetes drugs 0.0% 0.0% 0.1% 1.0% 0.7% 1.0%

Anti-infective drugs 0.2% 0.7% 0.5% 0.6% 0.5% 0.9%

Other neurologic drugs 0.1% 0.0% 0.4% 0.6% 1.5% 0.9%

FDA unapproved drugs — — — — — 0.8%

Diet aids 1.2% 2.4% 2.0% 1.2% 1.4% 0.4%

Emphysema and asthma

drugs 0.2% 0.2% 0.0% 0.2% 0.3% 0.4%

Migraine drugs 0.3% 0.4% 0.4% 0.3% 0.0% 0.1%

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16 3.3 Factors R elated to Drug Prevalence

Factors, such as pilot age, highest pilot certificate, flight operations, and

medical certificate, were analyzed to understand how they related to drug prevalence

by drug type.

Figure 4 depicts drug type prevalence by pilot age. For drugs that indicated

potentially impairing condition s, drug prevalence generally increased with age. The

prevalence of potentially impairing drugs also generally trended upward with age, except for the oldest pilots (>75 years), whose prevalence was similar to pilots in the

>40- to-50-year -old group. For controlled substances, the highest prevalence was

observed in pilots in the >40-to -50-year -old group, and for illicit drugs, the highest

prevalence was observed in pilots aged 40 and younger.

Figure 4 . Percent of pilots with positive toxicology findings by drug type and age group ,

2018– 2022. The number of pilots in each group is in parentheses .

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17 Figure 5 shows drug type prevalence by highest pilot certificate held. In

general, pilots who held ATP or commercial pilot certificates had the lowest drug

prevalence for all drug types. Pilots with no pilot certificate had the highest

prevalence of potentially impairing and illicit drugs. Pilots holding a sport pilot

certificate had the highest prevalence of drugs indicating potentially impairing

conditions and the highest prevalence of controlled substances.29

Figure 5 . Percent of pilots with positive toxicology findings by drug type and highest pilot

certificate held , 2018– 2022. The number of pilots in each group is in parentheses.

29 Figure 5 does not include one pilot who had a foreign license .

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18 Figure 6 depicts drug type prevalence by flight operation type. For all drug

types, drug prevalence was lower among fatally injured pilots who were operating

under Part 135 compared with those flying general aviatio n operations.30

Figure 6 . Percent of pilots with positive toxicology findings by drug type and flight operation

type , 2018– 2022. The number of pilots in each group is in parentheses.

30 The one pilot who was operating under 14 CFR Part 121 scheduled airline operations and

the one pilot who was operating under Canadian regulations are not included in figure 6 . Both pilots

were negative for all tested drugs.

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19 Figure 7 shows drug type prevalence by whether pilots had a medical

certificate that was still within the duration limits of a third -class certificate at the time

of the accident .31 Pilots whose medical certificate s were within the duration of a

third -class medical certificate had lower drug prevalence for all drug types compared

with pilots whose medical certificates were expired or who had no medical certificate .

Figure 7 . Percent of pilots with positive toxicology findings by drug type and medical

certificate level , 2018– 2022. The number of pilots in each group is in parentheses.

31 Two pilots who were Canadian and held Canadian medical certificates and one pilot whose

medical certificate was listed as unknown are not included in figure 7 .

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20 For those pilots classified as having a medical certificate, figure 8 shows drug

prevalence by the medical certificate’s issued class. For all drug types, drug

prevalence increased with decreasing medical certification class.

Figure 8 . Percent of pilots with positive toxicology findings by drug type and medical

certificate issued class, 2018– 2022. The number of pilots in each group is in parentheses.

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21 4 Discussion

This research update showed a continued increase in overall drug presence

among fatally injured pilots compared with the results of previous NTSB reports that

examined the periods 2013–2017 and 1990–2012 (NTSB 2020a, 2014). More than

half ( 52.8%) of fatally injured pilots tested positive for at least one drug, and more

than a quarter (2 7.7%) tested positive for two or more drugs. Changes in drug test

sensitivity and protocols may have contributed to some of the observed increases.

Among the four drug types analyzed in this report, two increased and two

decreased compared with the last research update. The largest increase was in illicit

drugs, which were detected in 7.4% of fatally injured pilots for the 5-year period

examined , a 2.4 percentage point increase over the previous 5-year period.

Potentially impairing drugs increased 0.6 percentage points to 28. 6%. Drugs used to

treat potentially impairing conditions decreased 1.6 percentage points to 13.5% , and

controlled substances decreased 3. 2 percentage points to 6.9%.

Drug prevalence was related to several factors , including age, flight

operations , and certification . The prevalence of potentially impairing drugs and drugs

indicating potentially impairing conditions were more common in older pilots. Drug prevalence of all types was lower among pilots conducting Part 135 operations

compared with those conducting general aviation operations . With respect to

certification , drug prevalence was lowest among pilots holding ATP or commercial

pilot certificates compared with thos e holding private, sport, or student pilot

certificates , or those with no pilot certificate . Similarly, drug prevalence was lowe r

among pilots whose medical certificate was still within the duration limits of a third -class certificate compared with those with expired or no medical certificates.

With regard to categories of drugs, the most commonly found were

cardiovascular drugs, sedating antihistamines, nonsedating OTC drugs,

cholesterol-lowering drugs, prostate/erectile dysfunction drugs, and illicit drugs. Two

of those categories —sedating antihistamines and illicit drugs —consisted of drugs that

are also considered potentially impairing.

4.1 Most Commonly Found Potentially Impairing Drugs

The most commonly detected drug category that included potentially

impairing drugs was sedating antihistamines, with 12.7% of all fatally injured pilots testing positive, a 0.8 percentage point increase from the previous 5-year period

analyzed in NTSB’s 2020 update (NTSB 2020a). Within the category of sedating

antihistamines, the most commonly found drug was diphenhydramine, accounting for

about half of all sedating antihistamine detections and present in 6.7% of all fatally injured pilots. Diphenhydramine has been the most commonly found potentially

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22 impairing drug in every NTSB report concerning drug use trends among fatally

injured pilots to date (NTSB 2020a, 2014). The second -most common sedating

antihistamine was cetirizine, which accounted for about one in four sedating

antihistamine detections and was present in 3.7% of all fatal ly injured pilots. Cetirizine

is not a first -generation sedating antihistamine, but it has more sedating potential

than other second -generation antihistamines , and it is listed as sedating in FAA

guidance to pilots and a viation m edical examiners (FAA 2024, 2022).

In 2014, the NTSB recommended that the FAA provide information to pilots

about potentially impairing drugs found in its toxicology reports and make pil ots

aware of any less impairing alternative drugs (NTSB 2014).32 Since that time, the FAA

has published and updated OTC medication guidance documents that include

guidance to pilots on nonsedating alternatives to several drugs, including

diphenhydramine and cetirizine (FAA 2024). Both drugs are also mentioned in the

FAA ’s 2022 update on a llergy, a ntihistamine , and immunotherapy m edication

information, and diphenhydramine is listed in the FAA’s 2023 update to the d o not

issue/ do not fly medication s list (FAA 2022, 2023b).

Illicit drugs was the second most common drug category that contained

potentially impairing drugs . Within that category, the most commonly found drug was

delta -9-THC, the primary psychoactive chemical in marijuana, accounting for nearly

three -quarters of illicit drug detections and present in 6.1% of all fatally injured pilots.

Marijuana is a drug with well-established impairing effects (Couper and o thers 2024).

In the 2020 update , the NTSB reported detecting marijuana in 4% of fatally injured

pilots for the period 2013–2017. During th at period , recreational marijuana use had

become legal in several states and, although the use of marijuana by airmen

remained prohibited under federal law, the NTSB noted that it was unclear whether

that knowledge was generally known or understood among general aviation pilots

(NTSB 2020a).

The NTSB conclude d in the 2020 research update that the increasing evidence

of marijuana use by pilots indicated a safety hazard that had not been effectively

addressed and recommended that the FAA revise the Aeronautical Information

Manual and the Pilot ’s Handbook of Aeronautical Knowledge to explicitly state

marijuana’ s classification as an illicit drug per federal law and, thus, its prohibited use

32 Safety Recommendation A-14-92 called on the FAA to “ Develop, publicize, and periodically

update information to educate pilots about the potentially impairing drugs identified in your

toxicology test results of fatally injured pilots, and make pilots aware of less impairing alternative drugs

if they are avai lable. ” Safety R ecommendation A-14-92 was classified Closed —Acceptable Action on

March 10, 2020.

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23 by airmen (A-20-12) (NTSB 2020a).33 The FAA updated the Pilot ’s Handbook of

Aeronautical Knowledge accordingly in 2023 (after the 2018–2022 period covered in

this research update ), but its 2025 update to the Aeronautical Information Manual did

not contain this information (FAA 2023a , 2025). The FAA has stated the information

will be included in its August 2026 update to the manual .34

Since the 2013–2017 period covered in the NTSB 2020 update , 16 additional

states have legalized the recreational use of marijuana, and several others have

legalized medical marijuana use or have decriminalized its use.35 Also , in 2024, the

DEA published a notice of proposed rulemaking (NPRM) concerning the transfer of

marijuana from Schedule I to Schedule III of the Controlled Substances Act .36 The

NTSB ’s respon se to the NPRM highlighted the importance of considering

transportation safety for any potential rescheduling .37 Executive Order 14370, issued

on December 18, 2025, states that “the Attorney General shall take all necessary

steps to complete the rulemaking process related to rescheduling marijuana to

Schedule III of the [Controlled Substances Act ] in the most expeditious manner in

accordance with federal law.”38 As of the publication of this report, marijuana remains

a Schedule I drug.

4.2 Use of Potentially Impairing FDA Unapproved Drugs

This research update introduced a new drug category, FDA u napproved

drugs. This category , which was present in 0.8% of all fatally injured pilots, included

CBD, delta -8-THC, mitragynine, and yohimbine . Two of those drugs, delta -8-THC and

33 The finding is discussed on page 14 and listed on page 17 of the 2020 research update

(NTSB 2020a) .

34 For more information concerning our communication with the FAA , see footnote 8 on page

3 of this report .

35 The 16 states where recreational marijuana use has become legal since 2018 include the

following : Arizona (2020) , Connecticut (2021) , Delaware (2023) , Illinois (2020) , Maryland (2023) ,

Michigan (2018) , Minnesota (2023) , Missouri (2022) , Montana (2021) , New Jers ey (2021) ,

New Mexico (2021) , New York (2021) , Ohio (2023) , Rhode Island (2022) , Vermont (2018) , and

Virginia (2021) . The year recreational marijuana became legal in each of these states is noted in

parentheses . For more information, s ee the Insurance Institute for Highway Safety ’s “Marijuana Laws”

web page, dated February 2026.

36 See the DEA ’s NPRM titled “Schedules of Controlled Substances: Rescheduling of

Marijuana,” published at 89 Federal Register 44597 on May 21, 2024.

37 See the NTSB’s July 19, 2024, response to the DEA’s NPRM .

38 See E xecutive Order 14370 of December 18, 2025, “Increasing Medical Marijuana and

Cannabidiol Research ,” published at 90 Federal Register 60541 on December 23, 2025.

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24 mitragynine, are potentially impairing drugs . Although there were only a few instances

in which pilots tested positive for these drugs (two cases involved delta -8-THC and

three cases involved mitragynine), there is evidence that these drugs could be an

emerging risk factor for transportation safety (Smith and others 2024; Vadiei, Evoy,

and Grundmann 2025 ).

Delta -8-THC in consumer products is typically chemically manufactured from

CBD, a chemical in the cannabis plant (Tagen and Klumpers 2022). It has been

marketed as a milder and more legal alternative to marijuana (Smith 2022). However,

it has similar psychoactive and intoxicating effects to marijuana, and delta -8-THC can

similarly impair motor coordination, reaction time, decision -making, problem solving,

and vigilance (CDC 2021). The emergence of delta -8-THC can be traced in part to the

Agriculture Improvement Act of 2018, which removed hemp with a delta -9-THC

concentration of 0.3% or less from the list of Schedule I drugs .39 Consequently , the

legal status of many delta -8-THC products became unclear at the federal level. In

November 2025, federal law was amended to exclude synthetic cannabinoids and

products containing more than 0.3 % total THCs from the hemp exception beginning

in November 2026. As a result of the law, delta -8-THC and similar psychoactive

cannabinoid products are set to return to the list of Schedule I drug s.40 State laws

concerning the use of del ta-8-THC vary , and the drug remains widely available online

and in retail stores.

Mitragynin e, the main psychoactive chemical in the herbal product kratom, has

stimulant effects at low doses and sedative effects at high doses. Kratom products are

widely available online and in retail stores . About half of all US states have laws

regulating it in some way while the other half have no laws specifically addressing it

(Legislative Analysis and Public Policy Association 2025).41 Although t he DEA has not

included kratom in the schedules of controlled substances , the DEA has identified

kratom as a d rug of concern.42

The FAA has not published clear policies or guidance relating specifically to

delta -8-THC. The agency added kratom to its d o not issue/ do not fly medic ations list

39 See the Agriculture Improvement Act of 2018, Public Law 115 –334, 132 Stat. 4490 (2018).

40 See the Continuing Appropriations, Agriculture, Legislative Branch, Military Construction

and Veterans Affairs, and Extensions Act, 2026 , Public Law 119 –37, 139 Stat. 495, section 781.

Executive Order 14370 of December 18, 2025, “ Increasing Medical Marijuana and Cannabidiol

Research ,” also called for an update to the statutory definition of final hemp -derived cannabinoid

products.

41 For example, in some states, kratom ’s components are designated as Schedule I controlled

substances , and in other states , the manufacture, possession, or sale of kratom products is regulated.

42 See the DEA ’s “Kratom” web page and its “Drug Fact Sheet : Kratom. ”

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25 in 2023 under the category “ OTC Active Dietary Supplement s,” and , also in 2023, the

Federal Air Surgeon ’s Medical Bulletin included an article warning about kratom ’s

effects and advised pilots to avoid its use (FAA 2023b ; Motta and Freitas 2023).

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26 Appendixes

Appendix A : Drugs Found in the Dataset Analyzed by Substance

Category and Drug Type

Table A-1. Drugs f ound in the dataset analyzed by substance category and drug t ype.

Substance

Category Parent Substance Common or Brand

Namea Potentially

Impairing Impairing

Condition Controlled

Substance Illicit

Drug

Antidepressants amitriptyline Vanatrip, Elavil,

Endep * *

Antidepressants bupropion Wellbutrin, Chantix * *

Antidepressants citalopram Celexa * *

Antidepressants duloxetine Cymbalta * *

Antidepressants fluoxetine Prozac * *

Antidepressants mirtazapine Remeron * *

Antidepressants quetiapine Seroquel * *

Antidepressants sertraline Zoloft * *

Antidepressants venlafaxine Effexor * *

Antidepressants vilazodone Viibryd * *

Anti-infective

drugs fluconazole Diflucan

Anti-infective

drugs trimethoprim Primsol, Trimpex,

Proloprim , Bactrim

Anti-seizure drugs gabapentin Neurontin * *

Anti-seizure drugs lamotrigine Lamictal * *

Anti-seizure drugs phenobarbitalb Solfoton, Luminal * * *

Anti-seizure drugs phenytoin Dilantin * *

Anti-seizure drugs topiramate Topamax * *

Benzodiazepines alprazolam Xanax * * *

Benzodiazepines clonazepam Klonopin * * *

Benzodiazepines diazepam Valium * * *

Benzodiazepines oxazepam Serax * * *

Benzodiazepines temazepam Restoril * * *

Blood thinners clopidogrel Plavix

Blood thinners salicylic acid aspirin

Blood thinners warfarin Coumadin

Cardiovascular

drugs amlopidine Norvasc

Cardiovascular

drugs atenolol Tenormin

Cardiovascular

drugs benazepril Lotensin

Cardiovascular

drugs carvedilol Coreg

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27 Substance

Category Parent Substance Common or Brand

Namea Potentially

Impairing Impairing

Condition Controlled

Substance Illicit

Drug

Cardiovascular

drugs (continued) chlorthalidone Thalitone, Hygroton

Cardiovascular

drugs diltiazem Cardizem

Cardiovascular

drugs flecainide Tambocor *

Cardiovascular

drugs hydrochlorothiazide HCTZ, Aquazide,

Hydrodiuril,

Microzide

Cardiovascular

drugs irbesartan Avapro

Cardiovascular

drugs losartan Cozaar

Cardiovascular

drugs metoprolol Lopressor,

metoprolol, Toprol

Cardiovascular

drugs propafenone Rythmol *

Cardiovascular

drugs propranolol Inderal

Cardiovascular

drugs sotalolc Betapace, Sorine *

Cardiovascular

drugs telmisartan Micardis

Cardiovascular

drugs torsemided Demadex

Cardiovascular

drugs triamterene Dyrenium

Cardiovascular

drugs valsartan Diovan

Cardiovascular

drugs verapamil Calan, Isoptin,

Verelan

Cholesterol -

lowering drugs atorvastatin Lipitor

Cholesterol -

lowering drugs pravastatin Pravachol

Cholesterol -

lowering drugs rosuvastatin Crestor

Diet aids phenterminee Adipex -P * *

Emphysema and

asthma drugs albuterol Ventolin, ProAir

FDA unapproved

drugs cannabidiol CBD

FDA unapproved

drugs delta -8-THC delta -8 *

FDA unapproved

drugs mitragynine kratom *

FDA unapproved

drugs yohimbine Testomar, Yocon

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28 Substance

Category Parent Substance Common or Brand

Namea Potentially

Impairing Impairing

Condition Controlled

Substance Illicit

Drug

Illicit drugs amphetamine amphetamine * *

Illicit drugs cocaine cocaine * *

Illicit drugs delta -9-THC marijuana * *

Illicit drugs ketamine ketamine * *

Illicit drugs methamphetamine methamphetamine * *

Migraine drugs sumatriptan Imitrex * *

Nausea/vertigo meclizine Dramamine Less

Drowsy, Antivert * *

Nausea/vertigo metoclopramide Reglan * *

Nausea/vertigo ondansetron Zofran *

Nausea/vertigo promethazine Phenergan * *

Nonsedating OTC

drugs cimetidine Tagamet

Nonsedating OTC

drugs deslorata dine Clarinex

Nonsedating OTC

drugs dextromethorphan cough suppressant

Nonsedating OTC

drugs famotidine Pepcid , Zantac 360

Nonsedating OTC

drugs fexofenadine Allegra

Nonsedating OTC

drugs guaifenesin Mucinex

Nonsedating OTC

drugs lansoprazole Prevacid

Nonsedating OTC

drugs lidocaine Xylocaine

Nonsedating OTC

drugs loratadine Claritin

Nonsedating OTC

drugs oxymetazoline Afrin

Nonsedating OTC

drugs pantoprazole Protonix

Nonsedating OTC

drugs pramoxine Proctofoam

Nonsedating OTC

drugs pseudoephedrine Sudafed

Nonsedating OTC

drugs ranitidine Taladine, Zantac

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29 Substance

Category Parent Substance Common or Brand

Namea Potentially

Impairing Impairing

Condition Controlled

Substance Illicit

Drug

Nonsedating pain

relievers acetaminophen Tylenol, Genapap,

Valorin

Nonsedating pain

relievers celecoxib Celebrex

Nonsedating pain

relievers diclofenac Cataflam, Voltaren

Nonsedating pain

relievers ibuprofen Advil, Motrin

Nonsedating pain

relievers ketorolac Toradol

Nonsedating pain

relievers meloxicam Vivlodex, Mobic

Nonsedating pain

relievers naproxen Aleve, Naprosyn

Oral diabetes

drugs glipizide Glucotrol, Glipizide

Oral diabetes

drugs pioglitazone Actos

Oral diabetes

drugs sitagliptinf Januvia

Other drugs hydroxychloroquine Plaquenil * *

Other drugs naloxone Suboxone *

Other drugs naltrexone Revia, Vivitrol *

Other drugs quinine tonic water ,

Qualaquin

Other drugs timolol Timoptic (eye drop),

Timolol (oral)

Other neurologic

drugs amphetamineg Adderall * * *

Other neurologic

drugs memantine Namenda *

Other neurologic

drugs methamphetamine Desoxyn * * *

Other neurologic

drugs methylphenidateh Ritalin * * *

Other neurologic

drugs modafinil Provigil * * *

Other neurologic

drugs ropinirole Requip * *

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30 Substance

Category Parent Substance Common or Brand

Namea Potentially

Impairing Impairing

Condition Controlled

Substance Illicit

Drug

Other

psychotropic

drugs buspirone Buspar, Vanspar * *

Other

psychotropic

drugs carisoprodol Soma * * *

Other

psychotropic

drugs doxepin Sinequan * *

Other

psychotropic

drugs meprobamate Equanil, Miltown * * *

Other

psychotropic

drugs trazodone Desyrel, Oleptro * *

Prescription sleep

aids zolpidem Ambien * *

Prescription sleep

aids zopiclone Imovane * *

Prostate/erectile

dysfunction drugs alfuzosin Uroxatral

Prostate/erectile

dysfunction drugs sildenafil Viagra

Prostate/erectile

dysfunction drugs tadalafil Cialis

Prostate/erectile

dysfunction drugs tamsulosin Flomax

Prostate/erectile

dysfunction drugs terazosin Hytrin

Sedating

antihistimines brompheniramine Dimetapp *

Sedating

antihistimines cetirizine Zyrtec, Xyzal (as

levocetirizine) *

Sedating

antihistimines chlorpheniramine Chlor -Trimeton *

Sedating

antihistimines diphenhydramine Benadryl *

Sedating

antihistimines doxylamine Unisom, Nytol *

Sedating

antihistimines hydroxyzine Atarax, Vistaril *

Sedating

antihistimines pheniramine Avil *

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31 Substance

Category Parent Substance Common or Brand

Namea Potentially

Impairing Impairing

Condition Controlled

Substance Illicit

Drug

Sedating pain

relievers buprenorphine Buprenex , Subutex,

Suboxone * * *

Sedating pain

relievers butalbital Fiorinal, Fioricet * * *

Sedating pain

relievers butorphanol Stadol * * *

Sedating pain

relievers codeine Tylenol #3 * * *

Sedating pain

relievers cyclobenzaprine Flexeril * * *

Sedating pain

relievers fentanyl Duragesic * * *

Sedating pain

relievers hydrocodone Dilaudid, Vicodin,

Lortab * * *

Sedating pain

relievers morphine MS Contin * * *

Sedating pain

relievers oxycodone Oxycontin * * *

Sedating pain

relievers tramadol Ultram * * *

a The list of brands is not exhaustive. Additionally, some of the brand -name products listed may have

other ingredients.

b In a previous NTSB report , phenobarbital was not classified as a controlled substance (NTSB 2020a) .

c In previous NTSB reports, sotalol was not classified as a drug used to treat potentially impairing

conditions (NTSB 2020a, 2014).

d In a previous NTSB report, torsemide was classified as a drug used to treat potentially impairing

conditions; however, this report does not clasify it as such (NTSB 2020a).

e In previous NTSB reports, phentermine was not classified as potentially impairing (NTSB 2020a,

2014).

f In a previous NTSB report, sitagliptin was classified as a drug used to treat potentially impairing

conditions; however, this report does not clasify it as such (NTSB 2020a).

g In a previous NTSB report, amphetamine (Adderall) was not classified as a drug used to treat

potentially impairing conditions (NTSB 2020a).

h In previous NTSB reports, methylphenidate was not classified as potentially impairing (NTSB 2020a,

2014).

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32 Appendix B: Drug Category Definitions

Antidepressants are used to treat depression. Examples include citalopram and

bupropion.

Anti -infective drugs are used to treat infections and include antibiotics and

antifungals. Examples include trimethoprim and fluconazole .

Anti -seizure drugs were initially intended to prevent seizures but are also used to

treat nerve pain and psychiatric diseases, such as bipolar disease. Examples include

gabapentin and lamotrigine .

Benzodiazepines are primarily used to treat anxiety. Examples include clonazepam

and diazepam .

Blood thinners are used to slow or prevent blood from forming clots. Examples

include salicylic acid (aspirin ) and warfarin .

Cardiovascular drugs are used to treat high blood pressure and heart failure or to

control heart rhythm. Examples include amlodipine and metoprolol .

Cholesterol -lowering drugs are used to treat high cholesterol. Examples include

atorvastatin and rosuvastatin .

Diet aids promote weight loss by increasing metabolism or depressing appetite.

Examples include phentermine .

Emphysema and asthma drugs are used to treat lung diseases and breathing

problems. Examples include albuterol and montelukast .

FDA unapproved drugs have neither been identified as federal ly controlled

substances nor are they approved by the FDA for therapeutic use . Examples include

delta -8-THC, mitragynine, yohimbine , and CBD . CBD is FDA approved only for

treatment of specific uncommon types of seizures; this research update assumed use

of other CBD products, which are widely available and are not FDA approved.

Illicit drugs are Schedule I drugs as defined by the DEA . The drugs, by definition,

have no accepted medical use and a high potential for abuse. Their use can lead to psychological or physical dependence. Examples include delta -9-THC and heroin. In

this research update , the Schedule II drugs amphetamine , cocaine, and

methamphetamine , and the Schedule III drug ketamine, were also defined as illicit

when there was evidence that they were used for nonmedical purposes. This research

update did not otherwise eva luate whether drugs had been used illicitly . Drugs in

other categories (for example, benzodiazepines and sedating pain relievers)

sometimes may be used illicitly .

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33 Migraine drugs are used to treat migraine, a neurological condition often

characterized by moderate to severe headache and other symptoms. Examples

include sumatriptan.

Nausea and vertigo drugs are used to treat an upset stomach or a feeling of

dizziness or motion sickness . Examples include meclizine and ondansetron.

Nonsedating OTC drugs are used to treat allergy, cold, and heartburn symptoms.

Examples include dextromethorphan, loratadine, famotidine, and fexofenadine .

Nonsedating pain relievers are used to treat pain and reduce fever. Examples

include acetaminophen, naproxen, and ibuprofen.

Oral diabetes drugs are used to control blood sugar levels in people with type 2

diabetes. Examples include glipizide and pioglitazone.

Other drugs include d quinine, which is commonly consumed as a bitterant in tonic

water ; hydroxychloroquine , which is used to treat autoimmune diseases; naloxone

and naltrexone, which are used in the treatment of opioid use disorders ; and timolol,

which is used to treat glaucoma . Notably, some of these drugs could also fit other

categories; consistent categorization was maintained with previous NTSB reports.

Other neurologic drugs are used to treat neurologic disorders other than seizures or

migraine , such as Parkinson ’s disease and attention -deficit /hyperactivity disorder.

Examples include ropinirole and methylpheni date.

Other psychotropic drugs are used to treat psychiatric diseases other than

depression or attention -deficit/hyperactivity disorder. Examples include buspirone

and meprobamate .

Prescription sleep aids are used to treat problems of falling and staying asleep.

Examples include zolpidem and zopiclone.

Prostate/erectile dysfunction drugs are used to treat an enlarged prostate gland,

which can cause urinary difficulties or male sexual problems. Examples include

tamsulosin and sildenafil .

Sedating antihistamines are drugs used to treat allergic symptoms and also cause

sleepiness. Examples include diphenhydramine, cetirizine, and doxylamine .

Sedating pain relievers are prescribed for moderate -to-severe pain. Examples

include tramadol and hydrocodone .

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34 References

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Cannabis Products Co ntaining Delta -8-THC and Reported Cases of Adverse

Events .” CDC Health Alert Network.

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J. Symoun, D. Smither, and A. Berning. 2024. Drugs and Human Performance

Fact Sheets: 2024. DOT HS 813 650. National Highway Traffic Safety

Administration .

FAA (Federal Aviation Administration). 2022. “ Allergy —Antihistamine &

Immunotherapy Medication ” from the Guide for Aviation Medical Examiners ,

updated October 26, 2022.

FAA. 2023a . Pilot ’s Handbook of A eronautical Knowledge . FAA-H -8083-25C.

FAA . 2023b . “Do Not Issue (DNI) Medications” and ”Do Not Fly (DNF) Medications ”

from the Guide for Aviation Medical Examiners , updated June 28, 2023.

FAA. 2024. “ Over -the-Counter (OTC) Medications Reference Guide: What OTC

Medications Can I Take and Still Be Safe to Fly?” from the Guide for Aviation

Medical Examiners , upda ted August 28, 2024.

FAA. 2025. Aeronautical Information Manual . Change 1, August 7, 2025.

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Postmortem Specimens: A Review of the Literature .” Forensic Science

International 165 (1): 10–29.

Legislative Analysis and Public Policy Association. 2025. Kratom: Summary of State

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Safety Research Report

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36 The NTSB is an independent federal agency charged by Congress with investigating every

civil aviation accident in the United States and significant events in the other modes of transportation—

railroad, transit, highway, marine, pipeline, and commercial space. We determine the probable causes

of the accidents and events we investigate and issue safety recommendations aimed at preventing

future occurrences. In addition, we conduct transportation safety research studies and offer information

and other assistan ce to family members and survivors for each accident or event we investigate. We also

serve as the appellate authority for enforcement actions involving aviation and mariner certificates

issued by the Federal Aviation Administration (FAA) and US Coast Guar d, and we adjudicate appeals of

civil penalty actions taken by the FAA.

The NTSB does not assign fault or blame for an accident or incident; rather, as specified by

NTSB regulation, “ accident/incident investigations are fact- finding proceedings with no formal issues

and no adverse parties … and are not conducted for the purpose of determining the rights or liabilities

of any person ” (Title 49 Code of Federal Regulations section 831.4). Assignment of fault or legal liability

is not relevant to the NTSB ’s statutory mission to improve transportation safety by investigating

accidents and incidents and issuing safety recommendations. In addition, statutory language prohibits

the admission into evidence or use of any part of an NTSB report related to an accident in a civil action

for damages resulting from a matter mentioned in the report (Title 49 United States Code section

1154(b)).

For more detailed background information on this report, visit the NTSB Case Analysis and

Reporting Online (CAROL) website and search for NTSB accident ID DCA24SS011. Rec ent publications

are available in their entirety on the NTSB website . Other information about available publications also

may be obtained from the website or by contacting —

National Transportation Safety Board

Records Management Division, CIO -40

490 L ’Enfant Plaza, SW

Washington, DC 20594

(800) 877 -6799 or (202) 314 -6551