The substance is the same under both trade names. Sexual activity may be a strain on your heart, especially if you have heart disease. Both Cialis and Viagra are effective at these doses. Condensation with 1-methylpiperazine. Other uses for this medicine This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Follow the manufacturer’s directions to use and clean the oral syringe.Viagra (sildenafil) as low as. $ View other PDE5 Inhibitors. Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. It is also used to treat . Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP. Viagra generic form. Viagra is a brand-name medication. It’s also available in a generic form called sildenafil. mg. Viagra comes in these strengths: 25 milligram (mg), 50 mg, and mg.