Alprazolam × Cetirizine

Alprazolam depresses the central nervous system, and its label approved by the US Food and Drug Administration (FDA) lists antihistamines among the drugs that add to this effect. At the recommended 10 mg dose, objective tests show no relevant effect of cetirizine on driving ability, but in sensitive patients other CNS depressants can further reduce attention and performance (cetirizine SmPC).

Drowsiness, reduced attention and slower reactions, impaired coordination (cetirizine SmPC; alprazolam SmPC). In older or debilitated patients alprazolam more often causes ataxia and oversedation (alprazolam SmPC).

The alprazolam label approved by the US Food and Drug Administration (FDA) requires limiting the dose and duration of alprazolam used with CNS depressants and lists antihistamines among them. The Spanish alprazolam SmPC sets the same limit for sedating antihistamines (alprazolam SmPC). The patient is warned about drowsiness and told not to drive or operate machinery until it is clear how they tolerate the combination; the cetirizine dose is not exceeded (cetirizine SmPC; alprazolam label, FDA). In older or debilitated patients alprazolam is started at 0.25 mg two or three times daily and kept at the lowest effective dose to avoid ataxia and oversedation (alprazolam SmPC). The US over-the-counter cetirizine label tells people taking tranquilizers or sedatives to ask a doctor or pharmacist before use (cetirizine label, FDA).