Men with untreated ED had relatively low baseline scores for all aspects of sexual function measured again using a 5-point scale in the IIEF. Sexual problems may be due to difficulties with arousal, a lack of desire or both. Patients should always ask their doctors for medical advice about adverse events. This site is intended only for U. The pharmacokinetics of sildenafil are dose-proportional over the recommended dose range. The pattern of responses was similar for the other principal question, the ability to achieve an erection sufficient for intercourse. Although the interaction between other protease inhibitors and sildenafil has not been studied, their concomitant use is expected to increase sildenafil levels.de venta promedio de Viagra Precio de Viagra en SingleCare; CVS Pharmacy: $ $ Walmart: $ $ Walgreens: $ $ Kroger Pharmacy: . Por otro lado, según el NHS, la Viagra puede causar efectos secundarios graves en menos de 1 de cada pacientes. Se recomienda dejar de tomar las pastillas y consultar con un médico: si. 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.