Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. Cialis helps you get and keep stronger erections with a daily or as-needed pill. PDE5 Inhibitors. Typically this takes the form of a tick box medical questionnaire, which is then reviewed by the pharmacist prior to supply. You can take this medicine with or without food 30 minutes before sex, depending on the dose. However, just like other medications, ED medications do have the potential to cause side effects and drug interactions in certain situations.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). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes . Clinically proven to treat men with erectile dysfunction (ED) Ongoing commitment to product quality and safety monitoring Learn More IF YOU CHOOSE BRAND-NAME VIAGRA, .