They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. Side effects Side effects of oral ED medicines are often mild. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. Tadalafil Cialis. Medicines that block an enzyme called CYP3A4. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines. The body takes longer to absorb it after a high-fat meal or alcohol.The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles . Schedule a COVID test now Virtual Care Don’t want to leave the house? Connect with a licensed provider 7 days a week from the comfort of home. Explore Virtual Care Loading MinuteClinic can treat over different conditions. Find a walk in location near you today. For further information, call , visit , or write: Viatris Inc., P.O. Box , Mission, KS See risks & benefits. Learn more about what VIAGRA® (sildenafil citrate), a prescription treatment for ED.