Moderate
Alprazolam × Valproic acid
Benzodiazepines. Short-to-medium-acting anxiolytics×Antiepileptics. Fatty acid derivatives
Mechanism
Valproate weakly suppresses hepatic alprazolam metabolism; alprazolam plasma levels may rise slightly. Plus additive sedation.
Symptoms
Additional drowsiness, ataxia. Older patients: fall risk. Symptoms appear in the first 1–2 weeks.
Management
Reduce alprazolam by 25% if needed. In older patients and prolonged therapy, monitor cognition and fall risk. Alternative anxiolytic without CYP dependence: lorazepam or oxazepam.