Xyzal side effects: A detailed guide

Key takeaways

• While Xyzal can cause mild side effects like drowsiness, dry mouth, or a sore throat, these often go away as your body adjusts to the medication. You can manage these effects by staying hydrated or taking your dose in the evening to sleep through any grogginess.
• Although uncommon, Xyzal may lead to more serious issues like urinary retention or psychiatric effects. It is important to speak with a doctor immediately if you have trouble urinating or notice significant changes in your mood or mental health.
• If you have been taking Xyzal for a long time, stopping suddenly can cause severe, widespread itching. To help avoid this, your doctor may recommend slowly tapering your dose rather than stopping all at once.

Overview

Xyzal is a brand-name medication known as a second-generation antihistamine used to manage allergy symptoms like a runny nose, sneezing, and itchy, watery eyes. It’s widely available over the counter (OTC) at pharmacies nationwide, and it contains the active ingredient levocetirizine.

Like any medication, Xyzal may cause some side effects, which may be mild or more serious. Let’s take a look at some of these side effects and ways to manage them.

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More common side effects of Xyzal

According to Xyzal’s prescribing information, the drug’s most common side effects in people older than 12 years include:

• sleepiness
• nasopharyngitis (inflamed nasal passages)
• fatigue
• dry mouth
• sore throat

Younger patients may experience different side effects, including fever, nosebleeds, diarrhea, and vomiting.

Common side effects are defined in the prescribing information as those reported in 2% or more of patients. The likelihood of experiencing some of these side effects tends to increase with higher Xyzal doses, whereas others seem more common at lower doses.

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Possible serious side effects of Xyzal

If you have any serious side effects from Xyzal, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.

Serious side effects of Xyzal are rare. Many were not identified in clinical trials of the medication before the drug was approved, but have been reported by patients after approval.

After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with Xyzal.

Some potential serious side effects of Xyzal include:

• urinary retention
• seizures
• psychiatric effects like depression or agitation
• heart palpitations
• allergic reactions

Because these effects were reported after drug approval and in small populations, it’s difficult to estimate their true likelihood. They’re likely to be very uncommon.

Allergic reaction

In general, symptoms of an allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Xyzal, your doctor may recommend taking a different medication instead.

Managing Xyzal’s side effects

In many cases, the side effects of Xyzal don’t require medical attention and may go away as your body gets used to the medication. If the side effects become intolerable or don’t go away, speak with a healthcare professional. They may be able to give you some tips to manage the effects, or they may recommend an alternative treatment.

Here are some tips for managing the more common side effects of Xyzal:

• Drowsiness: Sleepiness, fatigue, and weakness can be common with Xyzal. Taking the drug before you go to bed so that it works while you’re sleeping can help to manage this effect. Aim to avoid driving or using machinery if Xyzal makes you drowsy, and avoid alcohol or other sedatives to avoid worsening this effect.
• Dry mouth: Staying hydrated can help manage a dry mouth You can also try to stimulate saliva production by chewing sugar-free gum or sucking on hard candies.
• Nasopharyngitis: Nasopharyngitis is more commonly known as a cold. Its symptoms may be managed with hydration, saline nasal rinses, and saltwater gargles. Honey may also soothe a sore throat.

Frequently asked questions about Xyzal’s side effects

Here are the answers to some common questions about the side effects of Xyzal.

Does Xyzal make you drowsy?

Somnolence (drowsiness) is listed as a possible, more common side effect of Xyzal. However, it may be slightly less likely to cause this effect than other antihistamines.

Antihistamines are categorized into different generations. First-generation antihistamines are more likely to affect your central nervous system and are more associated with side effects like drowsiness. Xyzal, however, is known as a second-generation antihistamine.

In 2026, medical guidelines have shifted almost entirely away from older, first-generation drugs (like Benadryl) in favor of the newer second and third-generation options.

Does stopping Xyzal have any side effects?

Stopping Xyzal may lead to a condition known as new-onset pruritus (severe itching). This typically happens within a few days of stopping the drug, and it’s most common in people who have used Xyzal for a long-term period of several months to years.

When stopping Xyzal, doctors might recommend slowly tapering the dose rather than just stopping the medication all at once. This may help reduce the risk of this side effect.

Are there any warnings with Xyzal?

The Xyzal prescribing information lists warnings for the following side effects:

• Drowsiness: Xyzal may cause fatigue, weakness, and somnolence. You should avoid engaging in hazardous activities that require complete mental alertness and motor coordination, such as driving or operating machinery, until you know how the medication affects you.
• Urinary retention: Postmarketing reports indicate that Xyzal can cause urinary retention. It should be used with caution in individuals more likely to develop this condition, such as those with a spinal cord lesion or prostatic hyperplasia (enlarged prostate). Use of the drug should be discontinued if urinary retention occurs.
• New Onset Pruritus (Severe Itching) After Discontinuation: Some patients have reported widespread, severe itching within a few days of stopping Xyzal, typically after long-term use (months to years). These symptoms may improve by restarting or gradually tapering the medication.
• Renal Impairment: Because Xyzal is primarily excreted by the kidneys, patients with impaired renal function may have a higher risk of adverse reactions. Dosage adjustments are required for patients with various degrees of renal impairment.

Summary

Like any medication Xyzal can cause some side effects. These are usually mild and go away with time as your body gets used to the medication. The most common include drowsiness, dry mouth, and a sore throat.

If you experience side effects of Xyzal that don’t go away or become too severe for you to manage, reach out to a healthcare professional.

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Disclaimer: While Optum Perks strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses.