Montelukast has been evaluated for safety in approximately 2950 adult and adolescent patients 15 years of age and older in clinical trials. In placebo-controlled clinical trials, the following adverse experiences reported with montelukast (M) occurred in greater than or equal to 1% of patients and at an incidence greater than that in patients treated with placebo (P), regardless of causality assessment.
Body As A Whole:
Asthenia/fatigue M (1.8%), P (1.2%). Fever: M (0.6%), P (3.0%). Abdominal Pain: M (2.9%), P (2.5%) Trauma: M (1.0%), P (0.8%).
Digestive System Disorders:
Dyspepsia M (2.1%), P (1.1%). Infectious gastroenteritis: M (2.1%), P (1.1%). Dental Pain: M (1.7%), P (1.0%).
Dizziness M (1.9%), P (1.4%). Headache: M (18.4%), P (18.1%).
Respiratory System Disorders:
Congestion, nasal M (1.6%), P (1.3%). Cough M (2.7%), P (2.4%). Influenza: M (4.2%), P (3.9%).
Skin/Skin Appendages Disorder:
Rash M (1.6%), P (1.2%).
Laboratory Adverse Experiences:
* ALT increased M (2.1%), P (2.0%). AST increased M (1.6%), P (1.2%). Pyuria: M (1.0%), P (0.9%).
There have been occasional reports of mild and transient subjective side effects e.g., headache, dizziness, drowsiness, agitation, dry mouth and gastrointestinal discomfort.
The ECG effects of Cetirizine when administered a dose of up to six times the usual recommended dose did not prolong the QT interval.
Hypersensitivity reactions manifest as urticaria and fixed drug eruptions have been reported with Cetirizine.
CNS depression is the most common adverse effect of Cetirizine. The sedative effect can range from slight drowsiness to deep sleep.