If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. Other uses for this medicine This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Take sildenafil at around the same times every day. What side effects can this medication cause? If you experience chest pain, dizziness, or nausea during sexual activity, call your doctor immediately and avoid sexual activity until your doctor tells you otherwise. Do not keep outdated medicine or medicine no longer needed. John’s wort.Refill and transfer prescriptions online or find a CVS Pharmacy near you. Shop online, see ExtraCare deals, find MinuteClinic locations and more. Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the . Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour.