Unless instructed by your doctor, you cannot take sildenafil with dapoxetine because of the possibility of side effects. Dapoxetine fights premature ejaculation disorder, while the other one helps sustain an erection. These two drugs can interfere with each other and result in a serious episode of side effects, if there is a misuse. Your doctor always recommends the actual dosage. Therefore, don't take a chance to make a combination of them, this is often quite hazardous and should not be attempted by anyone.