Are there any problems in your relationship with your sexual partner? What medications do you take, including any herbal remedies or supplements? Use only the brand of this medicine that your doctor prescribed. Involve your sexual partner. It is important to tell your doctor about any heart problems you have now or may have had in the past. Write down any symptoms you’ve had, including any that might seem unrelated to erectile dysfunction.Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in adult . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes . VIAGRA can cause your blood pressure to drop suddenly to an unsafe level if taken with certain other medicines. Do not take VIAGRA if you take any other medicines called .