CONCOMITANT USE OF DULOXETINE WITH FLUVOXAMINE, AN INHIBITOR OF CYP1A2, RESULTS IN APPROXIMATELY A 6-FOLD INCREASE IN AUC AND ABOUT A 2.5-FOLD INCREASE IN CMAX OF DULOXETINE. SOME QUINOLONE ANTIBIOTICS WOULD BE EXPECTED TO HAVE SIMILAR EFFECTS AND THESE COMBINATIONS SHOULD BE AVOIDED.
PAROXETINE INCREASES THE CONCENTRATION OF DULOXETINE BY ABOUT 60%, AND GREATER DEGREES OF INHIBITION ARE EXPECTED WITH HIGHER DOSES OF PAROXETINE.
CO-ADMINISTRATION OF DRUGS WHICH HAVE A NARROW THERAPEUTIC INDEX, INCLUDING CERTAIN ANTIDEPRESSANTS (TRICYCLIC ANTIDEPRESSANTS [TCAS). SUCH AS DESIPRAMINE, NORTRIPTYLINE, AMITRIPTYLINE, AND IMIPRAMINE), PHENOTHIAZINES AND TYPE 1C ANTIARRHYTHMICS (E.G., PROPAFENONE. FLECAINIDE), SHOULD BE APPROACHED WITH CAUTION.
DUXET AND THIORIDAZINE SHOULD NOT HE CO-ADMINISTERED BECAUSE OF THE RISK OF SERIOUS VENTRICULAR ARRHYTHMIAS AND SUDDEN DEATH.
BECAUSE DUXET IS AN INHIBITOR OF BOTH SEROTONIN AND NOREPINEPHRINE REUPTAKE, IT IS RECOMMENDED THAT DUXET NOT BE USED IN COMBINATION WITH AN MAOI, OR WITHIN AT LEAST 14 DAYS OF DISCONTINUING TREATMENT WITH AN MAOI TO AVOID A SUDDEN RISE IN SEROTONIN AND NOR EPINEPHRINE SERUM LEVELS.