Fildena 50 is commonly prescribed to men with ED to help them regain sexual function. It is typically taken in pill form about 30 minutes to an hour before sexual activity, with effects lasting for around 4 to 6 hours. Fildena 50mg does not work automatically, as sexual arousal is still needed for the medication to be effective. After undergoing major surgery or dealing with a serious illness, many men experience ED as part of their recovery process. Surgeries like prostatectomy (removal of the prostate) or heart surgery can cause physical changes that lead to ED. For example, nerve damage during prostate surgery or reduced blood flow due to heart surgery can interfere with the normal process of achieving an erection.