At the same time, on-treatment function was better in treated patients who were less impaired at baseline. Storage Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. In addition, patients were asked a global efficacy question and an optional partner questionnaire was administered. Concomitant administration of strong CYP3A4 inducers, such as rifampin, is expected to cause greater decreases in plasma levels of sildenafil. This medicine comes with a patient information leaflet. What Are the Symptoms of Erectile Dysfunction? In many of the studies, of both fixed dose and titration designs, daily diaries were kept by patients. · Initially named compound UK,, sildenafil (sold under the brand name Viagra) was developed to treat hypertension and angina, when reduced blood flow to the heart causes chest pains.. In the. $12 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 pulmonary arterial hypertension, a serious heart and lung condition. This drug is more popular than comparable drugs. It is available in generic and brand versions.  · For treatment of erectile dysfunction: For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. Your doctor may adjust your dose if needed.