Levocetirizine Side Effects
Levocetirizine commonly causes somnolence in approximately 8% of patients, with other common side effects including dry mouth, fatigue, and headache, and it is contraindicated in patients with kidney disease. 1, 2
Common Side Effects
- Somnolence/drowsiness (8%) - less sedating than first-generation antihistamines but still causes significant drowsiness 1
- Fatigue (6%) 1
- Dry mouth 1
- Headache 3
- Mild gastrointestinal effects (nausea, vomiting) 4
Severe or Important Side Effects
- Performance impairment - can affect driving and school performance even without subjective awareness of sedation 1
- CNS effects - can be enhanced when combined with alcohol or other CNS depressants 1
- Anticholinergic effects - less pronounced than first-generation antihistamines but still present 1
Special Populations and Contraindications
Absolute Contraindications
- Kidney disease - levocetirizine is explicitly contraindicated in patients with kidney disease 2
- History of allergic reactions to levocetirizine, cetirizine, or any ingredients in the formulation 2
Use with Caution
- Elderly patients - increased risk of adverse effects due to decreased renal clearance 5
- Children under 6 years - consultation with a doctor is necessary before use 5
- Pregnancy - especially first trimester, should be avoided unless clearly needed 5
Dosage Considerations
- Standard adult dose is 5 mg once daily 4
- Higher doses (up to 20 mg) may be used in difficult-to-treat urticaria cases but increase the risk of side effects 6
- In moderate renal impairment, the dose should be halved to 2.5 mg daily 5
- Completely avoid in severe renal impairment (creatinine clearance <10 mL/min) 5
Advantages Over Other Antihistamines
- Rapid onset of action 7, 3
- Long duration of antihistaminic effect 7
- High bioavailability 3
- Low potential for drug interactions 7
- Limited distribution in the body 3
- Minimal hepatic metabolism 3
Monitoring and Patient Education
- Patients should be warned about possible drowsiness and advised to avoid driving or operating machinery until they know how the medication affects them 1
- Patients should avoid alcohol and other CNS depressants while taking levocetirizine 1
- Monitor for increased sedation, particularly in elderly patients or those on other sedating medications 5
Clinical Pearls
- Levocetirizine is the R-enantiomer of cetirizine and is generally more potent than other second-generation antihistamines like desloratadine and fexofenadine 7
- The side effect profile is generally better than first-generation antihistamines but somnolence remains a significant concern 1
- Even when taken at bedtime, the long half-life means sedative effects can persist into the next day 1