Moderate
Probable
説明
Cetirizine has mild CNS depressant properties that can be additive with the sedative effects of alprazolam, increasing the risk of excessive sedation, psychomotor impairment, and respiratory depression.
機序
Cetirizine, although a second-generation H1 antihistamine with reduced CNS penetration, still exerts measurable H1 antagonism in the brain, producing additive CNS depression with benzodiazepines acting on GABA-A receptors.
臨床的意義
Studies confirm additive sedation on psychomotor testing; the interaction is clinically relevant when both are used at higher doses or in elderly patients.
対処法
Advise patients against driving or operating machinery; consider reducing alprazolam dose; counsel on alcohol avoidance.