We considered cost, medications available, and whether generic versions were offered to help reduce costs. Dose-related visual disturbances occurred more frequently at toxic levels, while blood pressure changes showed a low correlation. Some platforms have a digital pharmacy that ships the medication to your home, while others send an electronic prescription to your local pharmacy. The following information includes only the average doses of this medicine. Some examples of nitrates are nitroglycerin Nitro-Dur, Nitrostat, others , isosorbide mononitrate Monoket and isosorbide dinitrate Bidil. Viagra is typically taken at a dose of 50mg about one hour before sex. These are commonly prescribed for an enlarged prostate or male pattern baldness.Sildenafil is a prescription drug. It comes in the form of a tablet and suspension (liquid). Both are taken by mouth. It also comes in an intravenous (IV) form, which is only given by a doctor. Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or alcohol. Its effects often last for 4 to 5 hours. It might work longer if you have mild to moderate erectile dysfunction. Make sure you get the right prescription and dose.  · Detailed Sildenafil dosage information for adults and the elderly. Includes dosages for Erectile Dysfunction and Pulmonary Hypertension; plus renal, liver and dialysis adjustments. provides accurate and independent information on more than 24, prescription drugs, over-the-counter medicines and natural products. This .