From the Guidelines
Atarax (hydroxyzine) can cause somnolence, and its use should be approached with caution due to its potential to cause sedation, performance impairment, and anticholinergic effects. This medication is a first-generation antihistamine, which has significant potential to cause sedation, performance impairment, and anticholinergic effects, as stated in the study published in the Journal of Allergy and Clinical Immunology 1. The study highlights that first-generation antihistamines such as diphenhydramine, hydroxyzine, and clemastine are associated with sedative effects, including drowsiness and/or performance impairment, in many patients.
Some key points to consider when prescribing or taking Atarax (hydroxyzine) include:
- The sedative effects of hydroxyzine can be significant, and patients may experience drowsiness and/or performance impairment, even if they do not subjectively feel sedated 1.
- The use of first-generation antihistamines like hydroxyzine has been associated with impaired learning and school performance in children, as well as driving impairment in adults 1.
- Concomitant use of other CNS-active substances, such as alcohol, sedatives, hypnotics, or antidepressant medication, may further enhance performance impairment from antihistamines like hydroxyzine 1.
- Older adults are more sensitive to the psychomotor impairment promoted by first-generation antihistamines and are at increased risk for complications such as fractures and subdural hematomas caused by falls 1.
It is essential to weigh the potential benefits of Atarax (hydroxyzine) against its potential risks and to consider alternative treatments with a lower likelihood of adverse effects, especially in vulnerable populations such as older adults or those with a history of substance abuse. If Atarax (hydroxyzine) is prescribed, patients should be advised to avoid driving or operating machinery until they know how the medication affects them and to report any concerns about sedation or performance impairment to their healthcare provider.
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.
- Somnolence: Yes, Atarax (hydroxyzine) can cause somnolence, as indicated by the warning against drowsiness in the drug label 2.
- Key consideration: Patients should be cautioned against driving or operating machinery due to the potential for drowsiness.
From the Research
Somnolence Associated with Atarax (Hydroxyzine)
- Atarax (hydroxyzine) has been reported to cause somnolence in several studies 3, 4, 5, 6, 7
- A study published in 2010 found that hydroxyzine was associated with a higher rate of sleepiness/drowsiness than active comparators 3
- Another study published in 1994 reported that sleepiness was the most common side effect of hydroxyzine, occurring in 28% of patients, and that it appeared during the first week of treatment and progressively disappeared later during treatment 6
- A 2011 study found that morning doses of hydroxyzine impaired performance on several psychomotor tests, suggesting that the sedative effect of hydroxyzine is more prominent after morning doses compared with evening doses 7
- The tendency of hydroxyzine to cause somnolence makes it an attractive option for patients with anxiety-induced insomnia, as noted in a 2024 case report 4
Comparison with Other Anxiolytic Agents
- Hydroxyzine was found to be equivalent in terms of efficacy, acceptability, and tolerability compared to other anxiolytic agents such as benzodiazepines and buspirone 3
- A study published in 1998 reported that hydroxyzine demonstrated greater and more rapid cognitive improvement compared to lorazepam 5