Cardiac Safety of Cetirizine

Introduction to Cardiac Safety

The British Journal of Dermatology guidelines note that cetirizine does not interact with medications that inhibit hepatic metabolism, unlike some other antihistamines that require caution with macrolide antibiotics, imidazole antifungals, or drugs with arrhythmic properties 1
The British Journal of Dermatology guidelines specifically state that mizolastine should not be taken with drugs that have arrhythmic properties, but make no such warnings for cetirizine, indicating a fundamental difference in cardiac safety profiles between the two antihistamines 1

Cetirizine is associated with mild sedation (13.7% vs 6.3% with placebo), which is a central nervous system effect rather than cardiovascular toxicity, according to the Journal of Allergy and Clinical Immunology 2
Renal impairment requires dose adjustment of cetirizine (halve the dose in moderate impairment, avoid in severe impairment with creatinine clearance <10 mL/min), due to drug accumulation and increased sedation risk, as noted in the British Journal of Dermatology 1, 4