Moderate
Alprazolam × Cetirizine
Benzodiazepines. Short-to-medium-acting anxiolytics×Second-generation antihistamines
Mechanism
Additive sedation. Cetirizine is a second-generation antihistamine with minimal blood-brain barrier penetration, but the effect adds up with alprazolam.
Symptoms
Drowsiness, sedation, ataxia. Older patients: fall risk. Symptoms appear in the first 1–2 days.
Management
Warn the patient about drowsiness, especially with the first dose. Alternative antihistamines with minimal sedation: fexofenadine or bilastine. In patients needing alprazolam, take antihistamines during the day, not at bedtime.