8 Hydroxyzine Side Effects You Should Know About

Hydroxyzine (Vistaril) can ease itching related to allergies. And it’s also sometimes prescribed for the relief of anxiety, though it’s not a first-choice medication for this purpose. There are two forms of hydroxyzine — hydroxyzine hydrochloride and hydroxyzine pamoate. These forms work similarly and carry similar risks and warnings.

If you've been prescribed hydroxyzine for itching or anxiety, you might be curious about its potential side effects. The good news is that most side effects of hydroxyzine are mild. And they usually resolve on their own after a short time. Let’s review eight important hydroxyzine side effects you should know about.

1. Drowsiness

Drowsiness is a very common hydroxyzine side effect. It happens because the medication can pass the blood-brain barrier. This is a group of cells that controls what does and does not enter the area surrounding the brain. But some medications can get through this barrier.

Hydroxyzine is a first-generation antihistamine, similar to diphenhydramine (Benadryl). It works by blocking histamine, a chemical in the body that plays a role in allergic reactions. By blocking histamine, hydroxyzine causes allergy symptoms to lessen or stop.

But, like other older antihistamines, hydroxyzine can pass the blood-brain barrier. And this can lead to drowsiness. Older antihistamines cause this side effect more often than newer ones, like fexofenadine (Allegra).

When you first start taking hydroxyzine, avoid activities that need your full attention, like driving, until you know its effects. You should also avoid other medications and substances that can worsen or amplify drowsiness. Examples include opioids, benzodiazepines, and alcohol.

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Some people may only need to take hydroxyzine once a day. If this is the case for you, try taking your hydroxyzine dose at bedtime. This can help limit drowsiness during waking hours.

If you’re taking hydroxyzine more than once a day and it’s causing you to feel sleepy during the daytime, talk to your healthcare provider. You may need a lower dosage of hydroxyzine or a different medication to manage your symptoms. But talk to your provider before making any changes to your medication regimen.

2. Dry mouth

Dry mouth is another common hydroxyzine side effect. Besides blocking histamine, hydroxyzine also blocks a chemical called acetylcholine. When a medication does this, it causes what’s called anticholinergic side effects. Dry mouth is one of many anticholinergic side effects that can occur when taking hydroxyzine.

Dry mouth related to hydroxyzine is usually mild and able to be managed at home. If you experience this side effect, there are steps you can take to help relieve it, including:

• Sucking on ice chips

• Drinking cool liquids throughout the day

• Chewing sugar-free gum or sucking on sugar-free hard candy

• Trying an over-the-counter (OTC) saliva substitute, such Biotene or BioXtra

If at-home remedies like the above don't work, talk to your healthcare provider. They may recommend that you stop taking hydroxyzine or that you try a prescription medication for dry mouth.

3. Headache

Headaches are another common hydroxyzine side effect. In fact, headaches are a possible side effect of all antihistamines. Typically, the headaches are mild. And, if you take hydroxyzine regularly, they may improve over time or stop after a dose adjustment.

If you have headaches while taking hydroxyzine, there are some home remedies you can try to get relief:

• Be sure to drink plenty of water and other fluids.

• Exercise regularly, or try to add more movement into your daily routine.

• Make sure you’re getting enough sleep at night.

• Take steps to lower your stress levels with activities like meditation or breathing exercises.

You can also ask your healthcare provider or pharmacist about taking an OTC pain reliever, like ibuprofen (Advil, Motrin) or acetaminophen (Tylenol). These can be helpful for occasional headaches. If your headaches don’t seem to get better or become severe, talk to your provider about next steps.

4. Constipation

Constipation is another potential hydroxyzine side effect. Like dry mouth, constipation is an anticholinergic side effect. Blocking acetylcholine slows the movement of food through the intestines. And this can lead to constipation in some people.

Like many other hydroxyzine side effects, constipation is usually temporary. To relieve constipation at home, try drinking more water and eating more fiber. If this doesn't work, you can try OTC medications for constipation, like laxatives or stool softeners.

Check in with your healthcare provider if your constipation doesn’t improve after a few days. And if it’s severe or gets worse at any point, contact your provider right away.

5. Higher risk of falls

Hydroxyzine can raise the risk of falls, especially in older adults. Some of the other side effects discussed above — such as drowsiness and dizziness — may contribute to the risk of falling, as well. To be safe, experts recommend adults age 65 and older avoid taking older antihistamines, such as hydroxyzine.

Be sure to discuss your options with your provider. There are allergy medications that carry a lower fall risk, such as loratadine (Claritin). There are also lower-risk anxiety medications available, such as buspirone. If you and your provider determine hydroxyzine is right for you despite the risks, ask about other steps you can take to help prevent falls.

6. Worsening of glaucoma

One rare but serious hydroxyzine side effect is a potential worsening of glaucoma. The technical term for this side effect, which can occur with all antihistamines, is acute angle-closure glaucoma. It’s a medical emergency and can lead to permanent blindness in severe cases and if left untreated.

People with narrow-angle glaucoma have the greatest risk of this side effect. But to be safe, tell your provider if you have any type of glaucoma before taking hydroxyzine.

If you have blurry vision, eye pain, or see halos around bright lights while taking hydroxyzine, seek medical help. These are possible symptoms of acute angle-closure glaucoma.

7. Trouble urinating

Trouble urinating (urinary retention) is another potentially serious hydroxyzine side effect. As with some of the above, trouble peeing is an anticholinergic side effect. You may feel like you can’t fully empty your bladder or, possibly, have lower stomach pain.

People with an enlarged prostate may have a higher risk of this side effect with hydroxyzine. There’s also a higher risk when hydroxyzine is combined with another medication that causes trouble urinating, such as amitriptyline or oxybutynin.

Urinary retention can become serious and lead to bladder or kidney infections. So if you experience this hydroxyzine side effect, talk to your healthcare provider. They may suggest that you try a different medication.

8. Heart rhythm problems

In very rare cases, hydroxyzine has been known to cause irregular heart rhythms (arrhythmias). It’s one of many medications that can prolong (lengthen) the QT interval, or the time between two heartbeats. Lengthening the QT interval can lead to severe or life-threatening arrhythmias.

People with certain heart problems may have a greater risk of arrhythmias related to hydroxyzine. Taking hydroxyzine with other QT-prolonging medications may also raise your risk. Some examples of these medications are antipsychotics and certain antibiotics, such as azithromycin (Zithromax).

Let your healthcare provider know if you have a heart condition before you start taking hydroxyzine. And make sure your provider knows what other medications and supplements you take. They’ll help you weigh the risks and benefits of taking hydroxyzine.

When should I contact my healthcare provider about hydroxyzine side effects?

Most hydroxyzine side effects are mild, temporary, and can be managed at home. But never hesitate to contact your healthcare provider or pharmacist if you have questions or if any of your side effects seem excessive or overly bothersome. Your provider can help you better understand the medication and its side effects, as well as discuss alternative treatments if needed.

If you experience any severe side effects — like trouble urinating or blurry vision with eye pain — contact your provider right away. This is also true if you develop symptoms of an allergic reaction, such as hives or a rash. Your provider may suggest that you stop taking hydroxyzine. Or they may recommend that you seek further care.

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Written by:

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP

Nicole E. Cieri-Hutcherson, PharmD, BCPS, NCMP, has over a decade of experience as a pharmacist, professor, and researcher. She was a full-time clinical professor in the pharmacy practice department at D’Youville School of Pharmacy before subsequently joining the faculty of the pharmacy practice department at the University at Buffalo School of Pharmacy and Pharmaceutical Sciences.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

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