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Levocetirizine side effects and how to avoid them

Levocetirizine side effects include weight gain, kidney problems, and hypotension
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By | Dec. 20, 2022 Medically reviewed by Josephine Bawab, Pharm.D.
Rx pill bottle and prescription pad: Levocetirizine side effects

Key takeaways

  • Levocetirizine, a second-generation antihistamine, is used to relieve allergy symptoms but can cause side effects such as sleepiness, weight gain, kidney problems, and hypotension.

  • Serious side effects of levocetirizine include seizures, fainting, low blood pressure, hallucinations, depression, and suicidal thoughts, which are more likely with long-term or overuse.

  • Side effects like drowsiness, dry mouth, and diarrhea are typically mild and can be managed at home, but serious side effects or allergic reactions require immediate medical attention.

  • To avoid levocetirizine side effects, follow dosing instructions carefully, avoid giving it to children under two without medical advice, consult a doctor if you have pre-existing conditions, and avoid alcohol and sedatives.

In this article:

   

Levocetirizine is a nonprescription antihistamine used to relieve the symptoms of hay fever or allergies: runny nose, itchy or watery eyes, and throat irritation. Prescription levocetirizine, on the other hand, is used to treat the symptoms of perennial allergic rhinitis (runny nose, nasal congestion, and sneezing) in children and chronic hives (urticaria) in children and adults. Also sold as brand-name Xyzal, levocetirizine is a second-generation or “non-drowsy” antihistamine that is chemically similar to Zyrtec (cetirizine). Histamines are a substance produced by the body in response to an allergen. They produce the symptoms of an allergic reaction including runny nose, nasal congestion, itching, and hives. 

Unlike first-generation antihistamines, levocetirizine does not easily cross into the brain, so it is less likely to cause drowsiness. Even with few side effects, levocetirizine can cause problems because of pre-existing medical conditions or possible drug interactions. It also has serious side effects of which people should be aware.

Common side effects of levocetirizine

The most commonly experienced side effects of levocetirizine depend on age. Levocetirizine can be given to children as young as six months of age. 

  • In adolescents and adults, the most commonly experienced side effects are sleepiness and nose and throat irritation
  • In children ages six to 12 years old, the most common side effects are fever and cough
  • In children between ages one and five years old, the most common side effects are fever and diarrhea
  • In infants younger than one year of age, the most common side effects are diarrhea and constipation

Side effects vary significantly based on age. Here’s a complete list of the most common side effects, no matter what the age:

  • Fever
  • Sleepiness
  • Diarrhea
  • Nose and throat swelling and irritation
  • Cough
  • Vomiting
  • Inflammation or infection of the middle ear
  • Tiredness
  • Dry mouth
  • Nosebleed
  • Constipation
  • Urinary retention

Serious side effects of levocetirizine

The most serious side effects of levocetirizine include:

  • Seizures
  • Fainting
  • Low blood pressure
  • Hallucinations
  • Depression
  • Suicidal thoughts
  • Severe allergic reactions

Weight gain

Although weight gain is not considered a side effect of levocetirizine, studies have shown that chronic use of antihistamines is associated with weight gain. Among other things, histamines are responsible for telling the brain not to be hungry, so people taking antihistamines feel hungry more often. Weight gain is a long-term side effect of antihistamine use and typically requires weeks or months of daily use. Although we don’t know which antihistamines are the worst offenders, weight gain is more strongly associated with the use of first-generation antihistamines like Benadryl. These antihistamines cross into the brain and are more likely to cause nervous system effects like drowsiness (which affects physical activity) and increased appetite. Newer antihistamines like levocetirizine may have less of an effect on weight. Still, over-the-counter (OTC) antihistamines should be used with caution. Follow the instructions and try not to overuse them. If weight increases when taking levocetirizine every day, then talk to a healthcare professional about alternative treatments.

Kidney problems

Levocetirizine does not harm the kidneys, but kidney dysfunction can cause problems in people taking the drug. The kidneys are responsible for clearing levocetirizine from the body. If the kidneys are not functioning well, then the medicine will build up in the body, making side effects more likely. For this reason, people with kidney disease should not take levocetirizine without talking to a healthcare provider.

Hypotension
Low blood pressure is a reported side effect of levocetirizine, but its incidence is unknown. In those who have reported low blood pressure, the side effect usually happens rapidly after the first dose. A drop in blood pressure right after taking a drug is usually a symptom of anaphylaxis, a rare allergic reaction associated with levocetirizine. No matter what the cause, if blood pressure goes down enough to cause symptoms, get immediate help. The warning signs of low blood pressure are lightheadedness, dizziness, weakness, blurred vision, confusion, and fainting.

How soon do levocetirizine side effects start?

Many of the most commonly-experienced side effects of levocetirizine happen early in treatment: drowsiness, diarrhea, nasal congestion, fever, and dry mouth. Some common side effects, like cough and sore throat, are delayed and may require a few weeks of regular dosing to become apparent. The most serious side effects, such as seizures, depression, and suicidal thoughts, are typically delayed and require regular dosing or overuse of the drug.

How long do levocetirizine side effects last?

The duration of levocetirizine side effects depends on how it’s being taken. If taken every once in a while, side effects will usually improve after the last dose. Since the drug has a half-life of eight to nine hours, expect side effects to go away by the next day. If levocetirizine is taken daily over a long period of time, then common side effects may improve in the first few weeks of drug discontinuation. Serious side effects, such as depression, suicidal thoughts, seizures, and hallucinations, should be ample reasons to stop taking levocetirizine. Allergy symptoms are not comparable to any of these serious adverse effects. If these problems do not get better when the drug is stopped, get medical attention.

What are the long-term side effects of levocetirizine?

Do not use OTC levocetirizine long term. If long-term antihistamine use is needed, get medical advice from a healthcare professional. Though serious side effects are rare when taking levocetirizine, they can happen after prolonged use or overuse of the drug. A possible long-term consequence of chronic use of levocetirizine is weight gain. 

Levocetirizine contraindications

Do not take levocetirizine if there has been any allergic reaction to levocetirizine or a related antihistamine, cetirizine. 

No one with kidney disease should take levocetirizine. Although levocetirizine can be prescribed to people with kidney disease, it is never prescribed to people with end-stage renal failure or those who are on hemodialysis.

Pregnancy

Levocetirizine can be taken during pregnancy. There is currently no evidence that levocetirizine can cause birth defects or affect pregnancy in any other way. 

Breastfeeding

Levocetirizine may be present in human breast milk, but it’s uncertain if there are any adverse effects on a nursing infant. Levocetirizine is not recommended in women who are breastfeeding. Prolonged use or overuse of levocetirizine may cause side effects in the infant or decrease milk production.

Children

The FDA has approved the use of prescription levocetirizine in children as young as six months of age as a prescription. OTC levocetirizine should not be given to children younger than two years of age. Talk to a healthcare professional about a prescription for those children. Younger children will typically be prescribed an oral solution rather than levocetirizine tablets. Always keep this medicine out of the reach of children.

Seniors

Although there is no evidence that people older than 65 years of age are more likely to have problems with levocetirizine than others, healthcare providers are urged to use lower doses when prescribing levocetirizine to seniors. However, people older than 65 years should not use OTC levocetirizine until talking to a healthcare provider.

Levocetirizine warnings

As a nonprescription drug, levocetirizine has few warnings of which people should be aware before taking it. 

Cautions

Levocetirizine can cause problems in people with pre-existing conditions. These include:

  • Kidney disease: The most concerning caution with levocetirizine is that it can cause problems in people with kidney disease. Prescribers can use it in people with mild to severe kidney disease if they reduce the dose. However, self-dosing is a different matter and there are no dosing guidelines for kidney impairment included in the package directions or the drug information sheet for OTC levocetirizine. Therefore, no one with kidney disease should take nonprescription levocetirizine without the direction of a healthcare provider.
  • Urinary retention: Levocetirizine could worsen urinary retention. If urinary retention is a problem, talk to a healthcare professional before using this medication.

Abuse

Levocetirizine is not habit-forming and will not cause physical dependency or withdrawal. 

Overdose

Call a poison control center or get medical attention if an overdose of levocetirizine is suspected. Symptoms may include drowsiness in adults, but children who have taken too much levocetirizine may initially become restless and agitated before feeling sleepy. The maximum dosage for ages six years and older is 5 mg per a 24-hour period. It is 2.5 mg for children between the ages of two and five years of age.

Levocetirizine interactions

Levocetirizine’s most significant drug interactions involve drugs that can also cause sedation. These include opioids, sedatives, barbiturates, benzodiazepines, antipsychotics, muscle relaxants, marijuana, and alcohol. These drugs aren’t prohibited, but people should expect to have problems with sleepiness, focus, attention, and other impairments when they’re combined with levocetirizine. 

Ritonavir, a drug used to treat HIVand hepatitis C, can increase the risk of levocetirizine side effects. Since ritonavir is a life-saving treatment, a different antihistamine should be considered.

How to avoid levocetirizine side effects

Like all nonprescription drugs, levocetirizine can be used without the supervision of a healthcare provider. However, levocetirizine can not only cause minor side effects, but it can also bring on serious problems. Here’s how to use this drug safely. 

1. Follow the directions

Follow the directions written on the box or the drug information sheet packaged in the box. Do not exceed the recommended dose. Do not take this medicine if the instructions prohibit it. Do not take extra medicine unless instructed to do so by a healthcare professional. 

2. Do not give levocetirizine to children younger than two years old

Children younger than two years of age should not be given OTC levocetirizine. Talk to a healthcare professional about a prescription instead.

3. Talk to a doctor

Just because levocetirizine can be purchased off of a drugstore or grocery shelf, it doesn’t mean that it’s always safe to take. Before purchasing levocetirizine, people with the following medical conditions should talk to a doctor first:

  • Ages 65 years and older
  • Kidney disease
  • Urinary retention problems
  • Pregnancy or planning to get pregnant
  • Breastfeeding or planning to breastfeed

4. Avoid alcohol

Drinking will worsen any sedative effects of levocetirizine, including sleepiness and inability to focus or concentrate. The same applies to marijuana, cannabidiols, or any other drugs or supplements that cause sleepiness.

5. Be careful when driving

As with all antihistamines, be careful about driving, operating machinery, or engaging in risky activities after taking a dose of levocetirizine.

How to treat side effects of levocetirizine

Side effects of levocetirizine are typically mild. Most can be handled at home, but a few will require medical attention.

Drowsiness

Drowsiness and sedation are best handled by resting. Sit down and do something easy. Avoid driving, operating machinery, or doing risky things until feeling more awake and alert. 

Dry mouth

Dry mouth can be handled with sugar-free gum or hard candy. If dry mouth is persistent or burdensome, consider changing to a different antihistamine.

Diarrhea

Diarrhea is mainly experienced by children taking levocetirizine. Make sure the child drinks fluids to stay hydrated. If diarrhea persists or gets severe, talk to a healthcare professional.

Fever

Fever is primarily experienced by children when taking levocetirizine. A mild fever can be handled with rest and quiet. A fever reducer like acetaminophen can help, but talk to a healthcare professional first. Do not use aspirin. 

Ear infection

If a child has signs of an ear infection, see a healthcare professional.

Urinary retention

Immediately contact a healthcare professional if it becomes painful or difficult to urinate or urination decreases.

Allergic reactions

Levocetirizine can cause a serious and even life-threatening allergic reaction called anaphylaxis. For that reason, stop taking levocetirizine and get medical attention if even minor symptoms of an allergic reaction occur:

  • Skin rash
  • Hives
  • Trouble breathing
  • Swelling of the face, mouth, lips, tongue, or throat
  • Lightheadedness
  • Dizziness
  • Confusion
  • Fainting

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