Duloxetine Cimetidine

D6 Tricyclic antidepressants (TCAs), benztropine, perphenazine, clozapine, haloperidol, codeine/oxycodone, risperidone, class Ic antiarrhythmics, 3 blockers, trazodone, paroxetine, maprotiline, amoxapine, duloxetine, mirtazapine (partly), venlafaxine, bupropion Fluoxetine, paroxetine, duloxetine, hydroxybupropion, methadone, cimetidine, haloperidol, quinidine, ritonavir Phenobarbital, rifampin... 

Fluoxetine, paroxetine, bupropion, duloxetine, and other CYP450 2D6 inhibitors may increase TCA concentrations Cimetidine may increase plasma concentrations of TCAs and cause anticholinergic symptoms Phenothiazines or haloperidol may raise TCA blood concentrations May alter effects of antihypertensive drugs may inhibit hypotensive effects of clonidine Use of TCAs with sympathomimetic agents may increase sympathetic activity Methylphenidate may inhibit metabolism of TCAs... 

Cimetidine may increase duloxetine and venlafaxine plasma levels, which may lead to an increase in their adverse effects. Famotidine does not appear to interact with duloxetine. 

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