Cimetidine and Duloxetine interaction

Inhibitors of CYP1A2 or Thioridazine : Avoid co-administration with CYMBALTA ( 5.12 )

Potential for Other Drugs to Affect CYMBALTA CYP1A2 Inhibitors — Co-administration of CYMBALTA with potent CYP1A2 inhibitors should be avoided [see Drug Interactions ( 7.1 )] .

Potent inhibitors of CYP1A2 should be avoided ( 7.1 )

The risk of BP decreases may be greater in patients taking concomitant medications that induce orthostatic hypotension (such as antihypertensives) or are potent CYP1A2 inhibitors [see Warnings and Precautions ( 5.12 ) and Drug Interactions ( 7.1 )] and in patients taking CYMBALTA at doses above 60 mg daily.

Inhibitors of CYP1A2 When CYMBALTA 60 mg was co-administered with fluvoxamine 100 mg, a potent CYP1A2 inhibitor, to male subjects (n=14) duloxetine AUC was increased approximately 6-fold, the C max was increased about 2.5-fold, and duloxetine t 1/2 was increased approximately 3-fold.

…apparently through an effect on certain microsomal enzyme systems, has been reported to reduce the hepatic metabolism of warfarin-type anticoagulants, phenytoin, propranolol, nifedipine, chlordiazepoxide, diazepam, certain tricyclic antidepressants, lidocaine, theophylline, and metronidazole, thereby delaying elimination and increasing blood levels of these drugs.