MajorBenzodiazepines. Short-to-medium-acting anxiolytics×Macrolide antibiotic
Updated · Methodology
Mechanism
Clarithromycin blocks CYP3A4 – the main alprazolam metabolic route. Alprazolam plasma levels rise 2- to 3-fold, with prolonged and stronger effect.
Symptoms
Prolonged sedation, drowsiness, dizziness, ataxia. Falls and fracture risk in older patients. Symptoms appear within 1–2 days.
Management
During clarithromycin therapy, halve the alprazolam dose. Alternative antibiotics: azithromycin or doxycycline (minimal CYP3A4 impact). Alternative benzodiazepines without CYP3A4 dependence: lorazepam, oxazepam.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Xanax (alprazolam) prescribing information (2016)– ; DailyMed setid 388e249d-b9b6-44c3-9f8f-880eced0239f
- AEMPS: Ficha técnica: Claritromicina (nº registro 75638), sección 4.5 (2025)– AEMPS, CIMA, nº registro 75638, sección 4.5
- AEMPS: Ficha técnica: Alprazolam (nº registro 61880), sección 4.5 (2026)– AEMPS, CIMA, nº registro 61880, revisión 09/2026, sección 4.5