From the Guidelines
Hydroxyzine can significantly impair driving ability due to its sedative effects, and patients should exercise extreme caution when operating a vehicle, especially when first starting the medication or after increasing the dose. The side effects of hydroxyzine that affect driving include drowsiness, sedation, and blurred vision, which are typically most pronounced during the first few days of treatment and may diminish as the body adjusts to the medication 1. Hydroxyzine is a first-generation antihistamine that works by blocking histamine receptors in the brain, explaining its sedative properties. The sedative effects can be more intense if hydroxyzine is combined with alcohol, other antihistamines, sleep medications, muscle relaxants, or opioid pain medications 1.
Some key points to consider when taking hydroxyzine and driving include:
- Starting with the lowest effective dose (typically 25mg) to minimize sedative effects
- Taking hydroxyzine at bedtime rather than during the day to reduce the impact on driving ability
- Assessing how the medication affects you personally before operating a vehicle
- Being aware that some people may experience less sedation than others, but it's crucial to prioritize caution
- Considering alternative, less sedating medications if drowsiness persists and interferes with daily activities, as recommended by recent guidelines 1.
It's essential to note that older adults are more sensitive to the psychomotor impairment promoted by first-generation antihistamines like hydroxyzine, and their use should be approached with caution in this population 1. Additionally, the temporal profile of adverse events affecting driving should be assessed, and the timing of multiple dosing in driving studies should consider the pharmacokinetics of the investigational drug and the tolerance observed in other clinical trials 1.
From the FDA Drug Label
Since drowsiness may occur with use of this drug, patients should be warned of this possibility and cautioned against driving a car or operating dangerous machinery while taking hydroxyzine.
The side effects of hydroxyzine on driving ability include drowsiness, which can impair a person's ability to drive safely. Patients should be cautioned against driving a car while taking hydroxyzine. 2
From the Research
Side Effects of Hydroxyzine on Driving Ability
- Hydroxyzine has been shown to increase the risk of road traffic crashes, particularly in individuals with long-term chronic diseases, such as psychiatric disorders 3.
- The risk of being responsible for an injurious road traffic crash is higher in hydroxyzine users with highest exposure levels 3.
- Hydroxyzine significantly impairs driving performance, as measured by standard deviation of lateral position (SDLP), after single and repeated doses 4.
- The impairment caused by hydroxyzine on driving performance is severe and only partly mitigates over time due to a lack of complete tolerance 4.
- Hydroxyzine causes significant impairment in cognitive and psychomotor function related to driving, including information processing, psychomotor speed, and reaction time 5.
- The combination of hydroxyzine and alcohol exacerbates the impairment of cognitive and psychomotor function related to driving 5.
- Doctors and pharmacists should inform patients about the potential risks of hydroxyzine on driving and operating machinery 6, 7.
- Patients taking hydroxyzine should be advised to exercise caution when driving, especially if they have complex medical conditions or take multiple drugs 6, 7.