Propranolol + Fluvoxamine Maleate Interaction

Description

Propranolol or Metoprolol: Reduce dose if coadministered with fluvoxamine and titrate more cautiously ( 7.3 ) . Based on a finding of substantial interactions of fluvoxamine with certain of these drugs (see later parts of this section and also WARNINGS AND PRECAUTIONS [ 5 ] for details) 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). Propranolol and Other Beta-Blockers: Coadministration of immediate-release fluvoxamine maleate tablets 100 mg per day and propranolol 160 mg per day in normal volunteers resulted in a mean five-fold increase (range 2 to 17) in minimum propranolol plasma concentrations.