Drugs That Can Impair Your Ability To Drive Safely

Safe driving is a complex task that requires good vision, the ability to stay alert and concentrate for the duration of the drive, and strength and flexibility (for example, to brake or to turn the head to check blind spots). Because certain substances, such as alcohol or illegal drugs, can impair safe driving, driving under the influence (DUI) of such substances is illegal in the United States.[1]

You may not realize, however, that many prescription and over-the-counter drugs also can affect cognitive function and motor or visual abilities that are necessary to drive safely. Driving impaired due to prescription or over-the-counter medications is considered DUI and can put you and others in danger.[2] In fact, research indicates that people who both drive and have been prescribed such medications are more likely to be involved in traffic accidents than those without a prescription.[3]

Several classes of drugs can impair driving, including certain pain medications, sleeping aids, and antipsychotic and antianxiety medications. The drug classes also include allergy medications, medicines to treat or prevent symptoms of motion sickness, muscle relaxants, antiseizure drugs and certain antidepressants.[4],[5],[6] Among the adverse effects of these drugs are drowsiness or sleepiness, impaired judgment or confusion, feeling dizzy or nauseous, blurred vision, inability to focus, slowed or uncoordinated movements or reaction times, tremors, and fainting.

For many drugs, a warning (such as to not operate heavy machinery, which includes driving a car) is included in the prescribing information and medication guides.[7] However, adverse events may not occur for every patient or may occur only when several prescription or over-the-counter drugs are taken at the same time, or in combination with alcohol or products containing cannabis in any form, including cannabidiol (CBD).[8]

Because people react differently to medications, it is important that you do not drive until you know how you are affected by a newly prescribed drug, a dose adjustment or a new over-the-counter drug.[9] Importantly, some adverse effects of drugs can last many hours or even until the next day. Generally, older adults are at a higher risk of such adverse events than younger people, not only because they are more likely to take multiple drugs at the same time, but also due to age-related changes in how quickly drugs are broken down and removed from the body.[10]

Table: Examples of Antidepressant, Antipsychotic, Antiseizure and Muscle Relaxant Drugs That Can Impair Driving[11],[12]

†Brand-name combination products that contain other active ingredients are not included.
*Designated as Limited Use by Public Citizen’s Health Research Group
**Designated as Do Not Use by Public Citizen’s Health Research Group
***Designated as Limited Use for epilepsy and Do Not Use for migraine prevention by Public Citizen’s Health Research Group

The Table above provides examples of antidepressant, antipsychotic, antiseizure and muscle relaxant drugs that can impair driving. Other drug classes that can impair driving include narcotic pain medications, benzodiazepines and Z-drugs, and antihistamines.

Narcotic pain medications

Narcotic pain medications, such as oxycodone (OXYCONTIN, ROXICODONE, ROXYBOND, XTAMPZA ER and generics), hydrocodone (HYSINGLA ER and generics) and tramadol (CONZIP and generics) are sedating and can cause lightheadedness, dizziness and fatigue.[13],[14] Be aware that some prescription cough medications contain opioids such as codeine or hydrocodone, which can cause drowsiness or dizziness.

If you take narcotic pain medications in combination with other products that have sedating effects (including benzodiazepines, first-generation antihistamines and alcohol), the impairing effects can increase.

Benzodiazepines and Z-drugs

Benzodiazepines, such as alprazolam (XANAX and generics), chlordiazepoxide (LIBRIUM and generics) and diazepam (DIAZEPAM INTENSOL, VALIUM and generics), are sedative hypnotics that are used to induce or maintain sleep and to treat acute anxiety. Another class of hypnotics — often called Z-drugs — includes eszopiclone (LUNESTA and generics), zaleplon (SONATA and generics) and zolpidem (AMBIEN and generics) and is approved for short-term relief of insomnia.

Because of the serious risks associated with these drugs, including abuse and addiction, Public Citizen’s Health Research Group classifies all benzodiazepines (except for alprazolam, which can be used to treat panic disorder) and Z-drugs as Do Not Use.

However, if you are taking one of these commonly prescribed drugs, be aware that they are intended to make you sleepy and can slow reflexes. Benzodiazepines also can distort vision and cause loss of balance, weakness or clumsiness.[15] Many of these drugs may continue to impair driving ability the day after the medication was taken.

Antihistamines

Antihistamines are often used to treat allergies or motion sickness. In particular, first-generation antihistamines such as diphenhydramine (BENADRYL and generics) and hydroxyzine (VISTARIL and generics) can be sedating, slowing reaction times and making it hard to think clearly or focus.[16],[17] Although second-generation antihistamines such as cetirizine (ZYRTEC ALLERGY and generics), fexofenadine (ALLEGRA ALLERGY and generics) and loratadine (CLARITIN and generics) are considered less sedating, it is still important to see whether these drugs cause dizziness or drowsiness for you, especially when you first start taking them. Antihistamines are also found in some over-the-counter sleep medications or cold and cough remedies, either alone or in combination with other active ingredients.

What You Can Do

Never drive if you are impaired, regardless of whether your impairment is due do alcohol, illegal drugs, cannabis, or any prescription or over-the-counter medication. Do not take new medications when you need to drive, and make sure to monitor your reactions to a new drug or dose adjustment first.

Regularly discuss all medications you are taking, including over-the-counter drugs and supplements, with your clinician and discuss whether any of the drugs or drug combinations you are taking can impair your ability to drive safely.

If you discover that a medication you are taking impairs your driving ability, discuss with your clinician whether you can switch to another drug, adjust the dose, or change the time of day you take the drug to help mitigate the impairing effects. Never discontinue prescription drugs without speaking to your clinician first.
 

References

[1] National Highway Traffic Safety Administration. There is more than one way to be under the influence. https://www.nhtsa.gov/campaign/prescription-and-over-counter-medicines. Accessed March 7, 2025.

[2] National Highway Traffic Safety Administration. Drug-impaired driving. https://www.nhtsa.gov/risky-driving/drug-impaired-driving. Accessed March 7, 2025.

[3] Downey LA, Hayley AC. Prescription medication use and crash risk: taking responsibility for a new global challenge. Lancet Public Health. 2021;6(6):e349-e350.

[4] Food and Drug Administration. Some medicines and driving don’t mix. March 12, 2024. https://www.fda.gov/consumers/consumer-updates/some-medicines-and-driving-dont-mix. Accessed March 7, 2025.

[5] Hetland A, Carr DB. Medications and impaired driving. Ann Pharmacother. 2014;48(4):494-506.

[6] Driving under the influence caused by medications. Worst Pills, Best Pills News. September 2020. https://www.worstpills.org/newsletters/view/1355. Accessed March 7, 2025.

[7] National Highway Traffic Safety Administration. Dangers of driving after taking prescription drugs or over-the-counter medicines. https://www.nhtsa.gov/drug-impaired-driving/dangers-driving-after-taking-prescription-drugs-or-over-counter-medicines. Accessed March 7, 2025.

[8] Food and Drug Administration. Some medicines and driving don’t mix. March 12, 2024. https://www.fda.gov/consumers/consumer-updates/some-medicines-and-driving-dont-mix. Accessed March 7, 2025.

[9] Food and Drug Administration. Driving when you are taking medications. https://www.fda.gov/media/76863/download. Accessed March 7, 2025.

[10] Drugs that can be dangerous for older adults. Worst Pills, Best Pills News. July 2024. https://www.worstpills.org/newsletters/view/1606. Accessed March 7, 2024.

[11] IBM Micromedex. Drug interactions. http://www.micromedexsolutions.com/home/dispatch. Search terms: “Impaired driving ability.” Accessed March 7, 2025.

[12] Hetland A, Carr DB. Medications and impaired driving. Ann Pharmacother. 2014;48(4):494-506.

[13] Ibid.

[14] Food and Drug Administration. Some medicines and driving don’t mix. March 12, 2024. https://www.fda.gov/consumers/consumer-updates/some-medicines-and-driving-dont-mix. Accessed March 7, 2025.

[15] Hetland A, Carr DB. Medications and impaired driving. Ann Pharmacother. 2014;48(4):494-506.

[16] Ibid.

[17] Food and Drug Administration. Some medicines and driving don’t mix. March 12, 2024. https://www.fda.gov/consumers/consumer-updates/some-medicines-and-driving-dont-mix. Accessed March 7, 2025.