Please expect up to 4 to 6 weeks for reimbursement. These are commonly prescribed for an enlarged prostate or male pattern baldness. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. Tadalafil Cialis. Side effects Side effects of oral ED medicines are often mild.CHOOSE BRAND-NAME VIAGRA The original little blue pill prescribed by doctors for over 20 years Clinically proven to treat men with erectile dysfunction (ED) Ongoing . Cost Overdose Ask your doctor Q&A Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a . Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or .