Hydroxyzine (Vistaril)* is a generic prescription medication used in adults and some children to:

  • treat anxiety
  • treat itching related to certain conditions, such as allergies and eczema
  • help produce sedation (a state of relaxation and sleepiness) before or after anesthesia is given for a medical procedure

Hydroxyzine comes as an oral tablet and oral capsule. Hydroxyzine also comes in an oral syrup and an injectable form, though this article does not cover them. For more information about these forms, talk with your doctor.

Hydroxyzine may be used as a short-term or long-term treatment. As with other drugs, hydroxyzine can cause side effects.

Read on to learn about potential common, mild, and serious side effects. For a general overview of hydroxyzine, including details about its uses, refer to this article. Your doctor can also tell you more about hydroxyzine.

* Hydroxyzine capsules are available as the brand-name drug Vistaril. In the past, hydroxyzine tablets were available as the brand-name drug Atarax. However, Atarax is no longer available.

Hydroxyzine can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took hydroxyzine in clinical trials of hydroxyzine tablets and hydroxyzine capsules:

* For more information about this side effect, see “Hydroxyzine: Side effect specifics” below.

Mild side effects can occur with hydroxyzine use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to the prescribing information for hydroxyzine tablets and hydroxyzine capsules.

Mild side effects that have been reported with hydroxyzine include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking hydroxyzine and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Hydroxyzine: Side effect specifics” below.]

Hydroxyzine may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to the prescribing information for hydroxyzine tablets and hydroxyzine capsules.

If you develop serious side effects while taking hydroxyzine, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

* For more information about this side effect, see “Hydroxyzine: Side effect specifics” below.
† An allergic reaction is possible after taking hydroxyzine. However, it’s not clear whether this side effect occurred in clinical trials of hydroxyzine tablets and hydroxyzine capsules. To learn more, see the “Hydroxyzine: Side effect specifics” section below.

Hydroxyzine may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

How do the side effects of hydroxyzine HCl oral tablets compare with hydroxyzine pamoate oral capsules?

The side effects of hydroxyzine are expected to be the same regardless of the form you take.

Hydroxyzine comes as an oral tablet, which is called hydroxyzine hydrochloride (sometimes abbreviated as hydroxyzine HCl). The drug also comes as an oral capsule called hydroxyzine pamoate. Throughout this article, the term “hydroxyzine” is used to describe the drug’s tablet and capsule forms.

For lists of possible side effects from hydroxyzine tablets and capsules, see the “Hydroxyzine: Mild side effects” and “Hydroxyzine: Serious side effects” sections above.

Does hydroxyzine cause different side effects in women versus men?

Most side effects of hydroxyzine are expected to be the same for females* and males* who take the drug.

However, hydroxyzine may cause specific side effects in females who are pregnant or breastfeeding. For details, see the “Hydroxyzine: Precautions” section below.

If you have questions about your risk of certain side effects from hydroxyzine, talk with your doctor or pharmacist.

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Is weight gain a side effect of hydroxyzine?

No, hydroxyzine isn’t known to cause weight gain. This wasn’t reported as a side effect in clinical trials of hydroxyzine tablets or hydroxyzine capsules.

If you’re concerned about weight changes while taking hydroxyzine, talk with your doctor. They can advise you on ways to maintain a weight that’s healthy for you.

Will hydroxyzine cause different side effects depending on the condition it is being used to treat, such as anxiety?

No, it’s not likely. The side effects of hydroxyzine are expected to be the same regardless of the condition it’s being used to treat. For example, side effects of hydroxyzine are likely the same when it’s taken for sleep* or for anxiety.

For lists of possible side effects from hydroxyzine, see the “Hydroxyzine: Mild side effects” and “Hydroxyzine: Serious side effects” sections above.

* For this use, hydroxyzine is taken to help produce sedation (a state of relaxation and sleepiness) with anesthesia. For details about hydroxyzine’s uses, see this article.

Can hydroxyzine cause certain side effects in older adults?

Yes, hydroxyzine may cause certain side effects in older adults (ages 65 years and older).

Specifically, the drug may cause confusion and extreme drowsiness in older adults. And older adults may have a higher risk of certain side effects of hydroxyzine, including dry mouth and constipation. For this reason, doctors may prescribe a lower dosage of hydroxyzine for older adults than for younger adults.

Keep in mind that older adults may have certain health conditions that affect how their bodies process hydroxyzine. These conditions include liver and kidney problems, which could increase the risk of side effects.

If you have questions about your risk of side effects with hydroxyzine based on your age, talk with your doctor.

Does hydroxyzine cause long-term side effects?

It’s not likely that hydroxyzine will cause long-term side effects. Most of the drug’s side effects go away within hours or days of starting or stopping the drug. No long-term side effects were reported in clinical trials of hydroxyzine tablets or hydroxyzine capsules.

Long-term side effects may refer to either of the following:

  • side effects that start during treatment and continue for a long time, even after treatment ends
  • side effects that occur after long-term use of the drug

If you have questions about hydroxyzine and long-term side effects, talk with your doctor.

Learn more about some of the side effects that hydroxyzine may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for hydroxyzine tablets and hydroxyzine capsules.

Headache

Headache may occur with hydroxyzine. It isn’t known how common this side effect was in clinical trials of hydroxyzine tablets or hydroxyzine capsules.

Headache with hydroxyzine is typically mild. And it often goes away within hours or days of starting or stopping the drug.

What you can do

If you have a headache that’s bothersome or long lasting during hydroxyzine treatment, talk with your doctor. They can recommend ways to ease this side effect. For example, they may suggest you take an over-the-counter pain reliever, such as naproxen (Aleve) or ibuprofen (Advil).

Dry mouth

Dry mouth may occur with hydroxyzine use. It’s not known how common this side effect was in clinical trials of hydroxyzine tablets or hydroxyzine capsules.

Symptoms of dry mouth can include:

  • bad breath
  • increased thirst
  • stringy or sticky saliva

What you can do

If you have dry mouth while taking hydroxyzine, talk with your doctor. They can recommend ways to ease this side effect.

For example, your doctor may suggest you avoid certain foods or drinks that could worsen dry mouth. Examples include drinks that are extremely hot or cold. You can also see this article for other remedies for dry mouth.

Hallucinations

Hydroxyzine may cause hallucinations. However, it isn’t known how often this side effect was reported in clinical trials of hydroxyzine tablets or hydroxyzine capsules.

With hallucinations, you may see, hear, smell, taste, or feel something that isn’t really there.

What you can do

If you hallucinate while taking hydroxyzine, talk with your doctor. They’ll likely switch you to a different medication to treat your condition.

Allergic reaction

As with most drugs, hydroxyzine can cause an allergic reaction in some people. However, it’s not clear whether this side effect occurred in clinical trials of hydroxyzine tablets and hydroxyzine capsules. That said, allergic reactions have been reported since hydroxyzine was approved for use.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking hydroxyzine. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take hydroxyzine. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are known as drug-condition or drug-factor interactions. The conditions and factors to consider include:

Heart problems. Before taking hydroxyzine, tell your doctor if you have any heart problems. Examples include abnormal heart rhythm, heart failure that’s causing symptoms, or a recent heart attack. Having any of these heart problems could increase your risk of long QT syndrome (a type of abnormal heart rhythm) as a side effect of the drug. If you have a heart problem, your doctor can recommend whether hydroxyzine is a safe treatment option for you.

Age. Doctors try to avoid prescribing hydroxyzine to older adults (ages 65 years and older) unless there aren’t other treatments they can take. This is because older adults have a higher risk of certain side effects from taking hydroxyzine. Examples include constipation, drowsiness, and dry mouth. If you’re an older adult and your doctor prescribes hydroxyzine for you, they’ll likely have you take a lower dose than is typical. They’ll also closely monitor you for any side effects during treatment.

Dementia. Hydroxyzine can cause side effects, including confusion and trouble paying attention. People with dementia may have a higher risk of these side effects if they take hydroxyzine. If you have dementia, your doctor will try to prescribe a treatment other than hydroxyzine when possible.

Kidney or liver problems. After you take a dose of hydroxyzine, your kidneys and liver break down and get rid of the drug. If you have a kidney or liver problem, your body may not break down hydroxyzine as well. This can cause the level of the drug in your body to become too high, which increases your risk of side effects. Your doctor can determine whether hydroxyzine is safe for you to take based on the severity of your kidney or liver problems.

Convulsions or seizures. Rarely, convulsions have been reported as a side effect with hydroxyzine treatment. Most cases appear to be due to taking hydroxyzine doses that are higher than recommended. However, the drug hasn’t been studied in people who experience seizures, such as those with epilepsy. It’s not known whether taking hydroxyzine could worsen your convulsions or seizures. Talk with your doctor to learn more about whether hydroxyzine is safe for you to take.

Allergic reaction. If you’ve had an allergic reaction to hydroxyzine or any of its ingredients, your doctor will likely not prescribe hydroxyzine. Taking hydroxyzine could cause you to have another allergic reaction. Ask your doctor what other medications may be better options for you.

Alcohol with hydroxyzine

You should not take hydroxyzine with alcohol. Doing so can worsen drowsiness, which is a side effect of hydroxyzine.

If you have questions about consuming alcohol while taking hydroxyzine, talk with your doctor.

Pregnancy and breastfeeding while taking hydroxyzine

Hydroxyzine is not safe to take during pregnancy or while breastfeeding. Clinical trials haven’t studied the use of hydroxyzine tablets and hydroxyzine capsules in pregnant or breastfeeding people.

It’s possible the drug may cause side effects in a child born to a person who took hydroxyzine while pregnant. If you breastfeed while taking hydroxyzine, it’s also possible that this can cause side effects in your child.

Your doctor will likely not prescribe hydroxyzine if you are pregnant or breastfeeding. They can recommend a different treatment option for your condition during these times.

Both mild and serious side effects may occur with hydroxyzine. However, most of the drug’s side effects are expected to be mild. If you have side effects that are long lasting or bothersome, talk with your doctor or pharmacist.

If you’d like to learn more about hydroxyzine, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug. You can also ask them about Vistaril, the brand-name version of hydroxyzine capsules.

A generic drug and its brand-name version contain the same active ingredient, so they’re expected to have the same side effects. Referring to the following articles about hydroxyzine can provide you with additional information:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.