The commonly prescribed drug by the doctors is
sildenafil or
Vardenafil (Levitra), which causes erections to be stronger and long lasting. However it may not be effective if you have uncontrolled diabetes, very low blood pressure (hypotension) or uncontrolled high blood pressure (hypertension), heart disease or heart failure, stroke or you are taking any nitrate drugs for angina, blood-thinning (anticoagulant) medications, antihypertensives or alpha blockers for enlarged prostate.