Serious reactions w/ MAOIs (do not use concomitantly w/ MAOIs or w/in 14 days of MAOI discontinuation; not to be administered w/in 7 days of dapoxetine discontinuation). Inhibits metabolism of thioridazine (resulting to augmented QTc interval prolongation; do not use concomitantly w/ dapoxetine or w/in 14 days of thioridazine discontinuation; do not administer w/in 7 days of dapoxetine discontinuation). May lead to incidence of serotonin-associated effects w/ serotonergic medicinal/herbal products (including MAOIs, L-tryptophan, triptans, tramadol, linezolid, SSRIs, SNRIs, lithium & St. John's wort prep) (do not use concomitantly w/ MAOIs or w/in 14 days of MAOI discontinuation; not to be administered w/in 7 days of dapoxetine discontinuation). Caution in use w/ CNS-active medicinal products eg, antiepileptics, antidepressants, antipsychotics, anxiolytics, sedative hypnotics. Clearance may be reduced w/ CYP2D6, CYP3A4 & flavin monooxygenase 1 inhibitors. Increased exposure w/ potent CYP3A4 inhibitors (eg, ketoconazole, itraconazole, ritonavir, saquinavir, telithromycin, nefazodone, nelfinavir & atazanavir) & moderate CYP3A4 inhibitors (eg, erythromycin, clarithromycin, fluconazole, amprenavir, fosamprenavir, aprepitant, verapamil, diltiazem); potent CYP2D6 inhibitors (eg, fluoxetine). Possible reduced orthostatic tolerance w/ PDE5 inhibitors; α-adrenergic receptor antagonists. Warfarin (chronic therapy) & other medicines that affect coagulation &/or platelet function. Increased somnolence & decreased alertness w/ ethanol.