Hydroxyzine for Sleep: What Five Studies Can Tell Us

If hydroxyzine makes you drowsy, the next question is how it affects the rest of the night and the following day. Falling asleep sooner, waking less, and being able to function the next morning are separate outcomes.

Five studies covered different kinds of sleep trouble

A 2023 systematic review, searching studies published through October 2022, found five studies with 207 participants across their treatment groups. Four were randomized trials and one was open-label. Participants were aged 18 to 70; 46.4% were women.¹

The studies included people with PTSD, cirrhosis, chronic hives, and depression with insomnia, as well as healthy volunteers. The total includes comparison groups and several conditions.¹

Hydroxyzine doses studied were 25 mg, 50 mg or 100 mg at bedtime. Results for falling asleep, staying asleep and sleep quality were mixed. The longest study lasted eight weeks. Safety reporting was poor, with four studies not reporting adverse-event outcomes adequately; this limits conclusions about tolerability.¹

The review authors considered a possible short-term role when previous treatment had failed or was unsuitable, while calling for longer studies with an active comparator. ¹

The hives trial separates sleep disturbance from daytime sedation

A 2014 randomized, double-blind crossover study² analyzed 24 patients with difficult-to-treat chronic spontaneous urticaria, meaning persistent hives. Each person received both regimens, for five days each:²

• Levocetirizine 15 mg daily plus hydroxyzine 50 mg at night.
• Levocetirizine 20 mg daily alone.

Both regimens improved hives, reported nighttime sleep disturbance and quality of life. There was no significant difference between them on those outcomes. Daytime sleepiness favored levocetirizine alone (P = 0.026).²

This compared two antihistamine regimens in people whose hives could disrupt sleep. It did not compare hydroxyzine alone with placebo in chronic insomnia. It also used different levocetirizine doses, so it cannot isolate the effect of adding hydroxyzine to an otherwise identical regimen.²

For a follow-up visit, “I fall asleep earlier but feel too sleepy to drive in the morning” describes a benefit and a problem that both need assessment.

Check the indication, other medicines and heart history

The U.S. hydroxyzine hydrochloride tablet label lists anxiety, itching associated with allergic conditions, and sedation around anesthesia. Insomnia treatment is off-label. Sedation in one setting does not establish a lasting insomnia benefit.³

The label contraindicates use with a prolonged QT interval, an electrical timing abnormality of the heart. It cautions about heart disease, electrolyte imbalance and medicines that can also affect heart rhythm, including certain antidepressants and antibiotics. A pharmacist should check the complete medicine list.³

Drowsiness can affect driving and machinery use. Other sedating medicines and alcohol can increase the effects. The same U.S. label contraindicates early-pregnancy use and says it should not be given to nursing mothers. Discuss pregnancy or breastfeeding before use.³

The UK regulator’s 2015 safety advice calls for the lowest effective dose for the shortest possible time and advises avoiding hydroxyzine in older people. It identifies low potassium or magnesium, slow heart rate, cardiovascular disease and a family history of sudden cardiac death among the factors relevant to heart-rhythm risk.⁴

Agree on the outcome and the review date

Bring the reason hydroxyzine was prescribed, the nights you take it, your other medicines and the next morning’s effects. Ask which symptom it is intended to treat, what improvement would justify continuing, and when to review it. A prescription for itching or anxiety may have a different purpose from a prescription intended mainly for sleep.

For persistent insomnia, ask about cognitive behavioral therapy for insomnia (CBT-I) or brief behavioral therapy. The Defense Health Agency’s⁵ 2025 guide describes these structured treatments and distinguishes them from sleep-hygiene tips alone.⁵

Did I Do That in My Sleep?, Chapter 10’s “Medicines Belong in Shared Decisions,” covers expected benefit, interactions, next-day impairment and a plan for review. Those are useful subjects to bring to the prescriber alongside any change in sleep timing.