Yes, Atarax is an antihistamine. It contains hydroxyzine hydrochloride, which is one of the most potent first-generation histamine blockers available. Unlike newer antihistamines you can buy over the counter, Atarax requires a prescription and causes significant drowsiness, which is why it’s used for more than just allergies.
How Atarax Works
Atarax blocks H1 receptors, the same targets that over-the-counter allergy medications like diphenhydramine (Benadryl) act on. When your body releases histamine during an allergic reaction, it binds to these receptors and triggers itching, swelling, hives, and other symptoms. By blocking those receptors, Atarax prevents histamine from doing its job.
What sets Atarax apart is that it also crosses into the brain easily, which is why it produces noticeable sedation and has calming effects on anxiety. This makes it useful for conditions beyond typical allergies, but it also means more side effects compared to newer antihistamines.
What Atarax Is Prescribed For
The FDA has approved Atarax for three main purposes:
- Itching from allergic conditions: chronic hives, eczema, contact dermatitis, and other forms of histamine-driven itch
- Anxiety and tension: short-term relief of anxiety symptoms, often when other options aren’t suitable
- Sedation before or after surgery: calming patients as part of anesthesia preparation
Its itch-relieving effects are strong and long-lasting. In studies of children with eczema, itching was significantly reduced within one hour of taking a dose, with more than 85% suppression lasting from two to twelve hours after a single dose.
Atarax vs. Newer Antihistamines
If you’ve taken cetirizine (Zyrtec) for allergies, you’ve actually taken a close chemical relative of hydroxyzine. Cetirizine is a metabolite of hydroxyzine, meaning your body naturally converts some hydroxyzine into cetirizine after you take it. The key difference is that cetirizine was designed to work primarily outside the brain, so it controls allergy symptoms with far less drowsiness.
In a head-to-head trial for chronic hives, cetirizine taken once daily was equally effective as hydroxyzine taken three times daily. But four patients in the hydroxyzine group dropped out due to sedation, compared to just one in the cetirizine group. For straightforward allergy relief, a second-generation antihistamine like cetirizine is usually the better choice. Atarax tends to be reserved for situations where its sedating and anti-anxiety properties are actually helpful, or when itching hasn’t responded to milder options.
Atarax vs. Vistaril
You may see hydroxyzine sold under two brand names: Atarax (hydroxyzine hydrochloride) and Vistaril (hydroxyzine pamoate). A longstanding belief in medicine holds that Atarax is better for itching while Vistaril is better for anxiety. This turns out to be based purely on tradition. There is no clinical evidence that either salt form has advantages over the other. Both deliver the same active drug to your body.
Common Side Effects
Because Atarax is a first-generation antihistamine that readily enters the brain, drowsiness is the most prominent side effect. Many people also experience dry mouth and headache. These effects are tied to the drug’s anticholinergic activity, meaning it blocks a chemical messenger involved in many automatic body functions like saliva production, digestion, and bladder control.
Less common side effects include dizziness, fast heartbeat, and trembling in the hands or feet. The sedation can be strong enough to impair driving and reaction time, especially in the first few days of use or when combined with other medications.
Risks With Alcohol and Sedating Medications
Mixing Atarax with alcohol is a significant concern. Alcohol amplifies the sedating effects, potentially leading to dangerous levels of drowsiness, impaired judgment, and slowed reflexes. The same applies to other sedating medications, including sleep aids, opioid pain relievers, and benzodiazepines. If you’re taking Atarax, avoid alcohol and be cautious about driving or operating machinery until you know how the drug affects you.
Special Concerns for Older Adults
The American Geriatrics Society lists hydroxyzine on its Beers Criteria, a widely used guide to medications that older adults should generally avoid. The recommendation to avoid it is rated with high-quality evidence and strong confidence. The reasons are specific: the body clears the drug more slowly with age, and its anticholinergic effects pose a greater risk of confusion, constipation, dry mouth, and other complications in older adults. If you’re over 65 and have been prescribed Atarax, it’s worth discussing alternatives.
Pregnancy and Breastfeeding
The product label recommends against using hydroxyzine during pregnancy due to limited data, though the available evidence is somewhat reassuring. Studies involving over 200 women who used hydroxyzine throughout pregnancy found no increase in birth defects. One study of 100 women showed no increased risk of miscarriage. However, two cases of temporary withdrawal symptoms in newborns have been reported when mothers took it in the final weeks before delivery, including jitteriness and feeding difficulties.
Whether hydroxyzine passes into breast milk isn’t fully established. Occasional doses are considered unlikely to cause problems in a nursing infant, but regular or higher doses may lead to drowsiness or irritability in the baby, and could potentially reduce milk supply.