Alcohol and other CNS depressants (opioids, antihistamines, antipsychotics, sedative antidepressants), strong CYP3A4 inhibitors (ketoconazole, itraconazole, clarithromycin, erythromycin, ritonavir/cobicistat) increase alprazolam levels, CYP3A4 inducers (rifampicin, carbamazepine, phenytoin, St John’s wort) reduce effect, fluconazole and diltiazem/verapamil may increase levels, grapefruit juice may increase sedation