Hydroxyzine is a sedating antihistamine that can be used short-term to treat anxiety and trouble sleeping, but is not meant for long-term use. Medicines typically used first-line for the treatment of anxiety are the antidepressants like the SSRIs or SNRIs (for example: paroxetine, sertraline, escitalopram).

Hydroxyzine can provide relief from generalized anxiety disorder (GAD) and insomnia until your other treatment starts to work. In many people, sleep will improve once the anxiety lessens and symptoms improve.

What are the FDA approved uses for hydroxyzine?

Hydroxyzine is a prescription antihistamine classified as an histamine H1 antagonist with sedating properties. It is similar to diphenhydramine (Benadryl), a common over-the-counter antihistamine. It is used:

• to treat anxiety (generalized anxiety disorder or GAD)
• to treat chronic itching due to allergies (hives, contact dermatitis)
• to help with sleep (as a sedative) before surgery

In some cases, it may also be used as an antiemetic to treat an upset stomach or vomiting, but it is not specifically approved by the FDA for this use.

Hydroxyzine comes as two different formulations: hydroxyzine hydrochloride (Atarax) and hydroxyzine pamoate (Vistaril). The brand name product Atarax is no longer marketed but you can get hydroxyzine hydrochloride as a generic medicine.

How does hydroxyzine work for anxiety?

Researchers are not exactly sure how hydroxyzine works for anxiety, but it does increase serotonin levels in your brain in addition to blocking histamine activity in the body. Serotonin is a neurotransmitter that plays a part in keeping your mood balanced, and the antihistamine effect causes drowsiness.

• Hydroxyzine has activity at the serotonergic (5HT2) receptors in the brain which may contribute to its anti-anxiety effect.
• Antihistamines which work at the H1 receptor, like hydroxyzine, can cause drowsiness, which may be helpful if you experience insomnia with your anxiety.

How quickly does it work?

Hydroxyzine starts to work quickly, usually within the first 15 to 30 minutes after you take a dose.

• Side effects like drowsiness, dry eyes, blurred vision, or a dry mouth, may occur quickly too. Sometimes, people can feel nauseous or have stomach upset when they take this medicine. Take the medicine with food to see if that helps.
• Do not drive or operate dangerous machinery until you know how this drug affects you. Avoid drinking alcohol and taking other medicines that may also make you drowsy.
• Over time, these side effects usually subside as you get used to the medicine.

How much should you take?

The usual starting oral dose of hydroxyzine for anxiety in adults is 25 to 50 mg up to four times daily as needed. For insomnia associated with anxiety, 50 milligrams (mg) at bedtime may be used. Your doctor may adjust your dose based on effectiveness or side effects.

The maximum single dose is 100 mg and the maximum dose per day is 400 mg. Lower doses or an alternative treatment may be need in older adults due to side effects.

• You can take this medicine with or without food, but if it upsets your stomach, it may help to take it with food.
• When taken to help with insomnia (trouble sleeping) due to anxiety, doses are taken at bedtime due to the drowsy effect.
• Follow your doctor’s dosing instructions exactly. High doses or an overdose of this medicine can be dangerous. If an overdose occurs, contact emergency medical help right away.

Be sure to tell your doctor and pharmacist about the medicines you use, including prescription, over-the-counter (OTC) or herbal and dietary supplements. Some common medicines have drug interactions with hydroxyzine and you may need a dose adjustment.

Related: Hydroxyzine drug interactions (in more detail)

Is hydroxyzine safe for older patients?

Use of this drug is often not recommended in patients over 65 years of age due to potent anticholinergic side effects like confusion, dry mouth, urinary retention and constipation. It can also lead to extreme drowsiness which may increase the risk for a fall.

Some research also suggests a link between prolonged use of medicines with anticholinergic properties, such as hydroxyzine, and the occurrence of dementia, particularly in older adults.

Certain guidelines (for example: Beers Criteria, Pharmacy Quality Alliance) consider hydroxyzine a high-risk drug in older patients. Elderly patients may need alternative treatments to safely treat anxiety or insomnia.

Learn more: Anticholinergic Drugs to Avoid in the Elderly

Can you take hydroxyzine daily? How long can you safely take it?

Hydroxyzine is not usually meant to be a long-term daily solution for anxiety or sleep for most people. Hydroxyzine may not work as well if you take it daily. You can build a tolerance to the medicine over time, which means your body gets used to the medicine and the effect lessens.

The manufacturer states that the effectiveness of hydroxyzine in treating anxiety for longer than 4 months has not been evaluated in studies; however, your doctor will monitor your response and can determine the appropriate length for treatment.

Hydroxyzine is not a controlled substance and is not physically habit-forming like Xanax (alprazolam), a benzodiazepine that is used to treat anxiety.

If you find your medicine is not working well for you, contact your doctor. You may need a dose adjustment or a different treatment. Do not adjust doses on your own.

Is hydroxyzine expensive?

No, generic hydroxyzine is usually very affordable. It is available as an oral tablet, capsule, oral syrup and as an injection.

All forms are available generically and 30 tablets usually costs less than $20 at the pharmacy. Injections may be more expensive, especially if they are given at your doctor's office or a hospital.

Prices can vary based on location, pharmacy, insurance and any discount coupons you may be using.

Bottom Line

• Hydroxyzine can be helpful for insomnia related to anxiety in the short-term, but is not meant for long-term use. Serotonin medicines are usually the initial long-term treatments used for anxiety.
• If you are experiencing anxiety or trouble sleeping, speak with your doctor about available treatments. Do not adjust medicines or doses on your own.
• Hydroxyzine can be associated with side effects like extreme drowsiness, dry mouth, confusion, urinary retention, and constipation, especially in the elderly. Some guidelines consider hydroxyzine a high-risk medicine in people over the age of 65 due to these anticholinergic side effects.

This is not all the information you need to know about hydroxyzine for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.