Viagra.

Viagra (sildenafil) helps achieve a harder and more stable erection in patients with erectile dysfunction. It is supposed to be taken as needed but you must never use it more often than once a day (every 24 hours). Viagra works by affecting the blood flow in your penis and helping you maintain the erection for longer than usual. However, you will need to take Viagra every time you want to have sex, as it's not a cure rather than a treatment. You will need to inform your doctor of the fact of using cimetidine, antifungal medications, rifampin, bosentan, diclofenac, enoxacin, isoniazid, heart or blood pressure medications, antibiotics, antidepressants, imatinib, conivaptan, or HIV/AIDS medicines, as any of those can interact with Viagra. Try to avoid drinking alcohol or using Viagra after a meal that contains fat – otherwise the absorption of Viagra can be slowed down and its side effects may be worsened. The following side effects are considered normal as long as they go away on their own: nosebleeds, heartburn, light sensitivity, diarrhea, insomnia, numbness, burning, or tingling, headache, muscle aches, flushing, and some changes in color vision.