- Subjects who require medications that inhibit the CYP450 2D6 pathway such as: Quinidine; Cimetidine; Type 1 antiarrhythmics; Phenothiazines; Selective serotonin reuptake inhibitors such as fluoxetine, paroxetine, and sertraline; Reserpine, other anticholinergic drugs, and sympathomimetic drugs