However, the regulatory control is not stringent, and thus illegal drug marketing is very common which leads to difficulty in monitoring their utilization and improve their outcome 19 , Rarely reported side effects include: an erection that will not go away priapism. Operational Definitions Recreational use: Use of a drug to advance certain activity sexual performance without a definite need or any medical condition. Dose adjustments due to interactions for sildenafil When used for Erectile dysfunction Manufacturer advises a starting dose of 25 mg with concurrent use of moderate and potent inhibitors of CYP3A4. Please expect up to 4 to 6 weeks for reimbursement. · Viagra comes as an oral tablet that contains the active drug sildenafil. Sildenafil is also available in generic form. Viagra is classified as a phosphodiesterase type 5 (PDE5) inhibitor. These medicines all work well for ED. When choosing one, tell your doctor or other health care professional what your preferences are, such as cost, ease of use, how long the drug’s effects last and side effects. Generic versions of sildenafil, vardenafil and tadalafil are available. Find Care near you; Buy 1, Get 1 50% OFF Buy 1, Get 1 50% OFF. Extra 15% off $30 Sitewid Not sold at your store. Check other stores Opens a simulated dialog. Shipping Available. Add for shipping will open overlay for Astroglide Rocket .