Cetirizine side effects
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Common Side Effects of Cetirizine
Cetirizine, a widely used second-generation antihistamine, is generally considered safe but is associated with several side effects. The most frequently reported side effect is somnolence (drowsiness), which occurs more often with cetirizine than with placebo or some other antihistamines. Studies consistently show that somnolence is a notable concern, especially at standard or higher doses, and can impact activities requiring alertness, such as driving 15710. Other common side effects include attention disturbance and mild psychomotor impairment, though these are less pronounced than with first-generation antihistamines 15.
Nervous System and Psychiatric Side Effects
Cetirizine has a higher potential for nervous system and psychiatric side effects compared to some other antihistamines. These can include somnolence, attention disturbance, hallucinations, aggression, and abnormal behavior. Such effects are more prominent in cetirizine than in loratadine, another popular antihistamine . Rarely, cetirizine has been linked to acute dystonic reactions and involuntary movements, particularly in pediatric patients and infants 239. Oculogyric crisis, a specific type of dystonic reaction affecting the eyes, has also been reported, especially in children .
Rare and Serious Adverse Reactions
Although rare, cetirizine can cause serious adverse reactions. Anaphylaxis, a severe allergic reaction, has been reported in isolated cases, even though cetirizine is often used to treat allergic reactions itself. This reaction can occur rapidly after ingestion and requires immediate medical attention . Additionally, there are reports of cetirizine causing pericarditis, a potentially serious inflammation of the heart lining, though this is very uncommon .
Overdose and Toxicity
While cetirizine is less likely to cause anticholinergic toxicity than first-generation antihistamines, overdose can still result in symptoms such as agitation, hallucinations, dilated pupils, rapid heartbeat, and high body temperature. These symptoms are more likely to occur in children and require prompt medical intervention .
Side Effects in Special Populations
Long-term use of cetirizine, especially in children, the elderly, and those with kidney problems, may increase the risk of side effects. These populations should be monitored closely for any adverse reactions, and dose adjustments may be necessary .
Comparison with Other Antihistamines
Compared to loratadine, cetirizine is less likely to cause nasal symptoms but more likely to cause nervous system and psychiatric side effects. Both drugs can cause drowsiness, but the risk is higher with cetirizine .
Conclusion
Cetirizine is effective for treating allergic conditions and is generally well-tolerated. However, it can cause drowsiness, attention disturbances, and, rarely, more serious nervous system or allergic reactions. Overdose can lead to anticholinergic toxicity, especially in children. Patients and clinicians should be aware of these potential side effects, particularly in vulnerable populations, and monitor for any unusual symptoms during treatment.
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