Hydroxyzine Side Effects and Precautions

Central Nervous System Effects

Drowsiness and performance impairment occur in many patients and can exist without subjective awareness of sedation, meaning patients may feel alert while still experiencing cognitive deficits 1, 2
Drivers responsible for fatal automobile accidents were 1.5 times more likely to be taking first-generation antihistamines like hydroxyzine compared to drivers not responsible for accidents 1, 3
Impaired driving performance with hydroxyzine worsens significantly with concurrent cell phone use 2, 3
Workers taking hydroxyzine exhibit impaired work performance, reduced productivity, and increased risk of occupational accidents 1
Performance impairment persists longer than plasma levels of the parent compound due to prolonged half-lives of hydroxyzine and its metabolites 1
Even bedtime-only dosing causes significant daytime drowsiness, decreased alertness, and performance impairment the following day 1, 3
Paradoxical CNS stimulation may occur, particularly in children 1, 2
Impaired learning and school performance in children 1

Older adults are more sensitive to psychomotor impairment from hydroxyzine 1, 3, 4
Increased risk for falls, fractures, and anticholinergic complications in elderly patients 1, 3
Hydroxyzine is contraindicated during early pregnancy 3, 4
Dose should be halved in moderate renal impairment and avoided in severe renal impairment 3, 4
Should be avoided in severe liver disease due to inappropriate sedating effects 3

Neonatal withdrawal symptoms can occur with maternal use, including tremors, irritability, hyperactivity, jitteriness, shrill cry, myoclonic jerks, hypotonia, increased respiratory and heart rates, feeding problems, and clonic movements 5
Withdrawal symptoms may last up to 5 weeks with treatment 5

Concomitant use with other CNS-active substances (alcohol, sedatives, hypnotics, antidepressants) further enhances performance impairment 1, 2