Alprazolam and Fluvoxamine interaction

Examples Nefazodone, fluvoxamine, cimetidine, erythromycin CYP3A Inducers Clinical implication Concomitant use of CYP3A inducers can increase alprazolam metabolism and therefore can decease plasma levels of alprazolam [see Clinical Pharmacology (12.3) ] .

Drugs demonstrated to be CYP3A inhibitors on the basis of clinical studies involving alprazolam: nefazodone, fluvoxamine, and cimetidine [see Drug Interaction (7.1) , Clinical Pharmacology (12.3) ] .

Alprazolam - When fluvoxamine maleate (100 mg q.d.) and alprazolam (1 mg q.i.d.) were coadministered to steady state, plasma concentrations and other pharmacokinetic parameters (AUC, C max , T ½ ) of alprazolam were approximately twice those observed when alprazolam was administered alone; oral clearance was reduced by about 50%.

The elevated plasma alprazolam concentrations resulted in decreased psychomotor performance and memory.

If alprazolam is coadministered with Fluvoxamine Maleate Tablets, the initial alprazolam dosage should be at least halved and titration to the lowest effective dose is recommended.

Moreover, as noted with alprazolam, the effect of fluvoxamine may even be more pronounced when it is administered at higher doses.

…Warnings and Precautions ( 5 ) ] and limited in vitro data for CYP3A4, it appears that fluvoxamine inhibits several cytochrome P450 isoenzymes that are known to be involved in the metabolism of other drugs such as: CYP1A2 (e.g., warfarin, theophylline, propranolol, tizanidine), CYP2C9 (e.g., warfarin), CYP3A4 (e.g., alprazolam), and CYP2C19 (e.g., omeprazole).