Adult Use: For the majority of individuals, a dose of 50 mg given as needed an hour before sexual activity is advised. The dose may be increased up to the maximum advised amount of 100 mg or decreased up to 25 mg depending on effectiveness and tolerability. The highest dose that is advised is 100 mg. One dose per day is the most frequently advised frequency.

Use in patients with impaired renal function: Patients with mild to moderate impaired renal function (creatinine clearance = 30-80 mL/min) do not require dose adjustment.

A 25-mg dose should be taken into consideration because sildenafil clearance is decreased in patients with substantially compromised renal function (creatinine clearance 30 mL/min).

Use in Patients with Impaired Hepatic Function: A dose of 25 mg should be taken into consideration since sildenafil clearance is decreased in patients with impaired hepatic function (such as cirrhosis).

Use in patients taking other medications: It is advised not to take more sildenafil than the maximum single dose of 25 mg during a 48-hour period due to the level of interaction in patients receiving concomitant therapy with ritonavir (see Interactions with Other Drugs).

Patients taking concurrent treatment with CYP3A4 inhibitors, such as erythromycin, saquinavir, ketoconazole, or itraconazole, should be given a beginning dose of 25 mg. Check out Drug and Other Interactions.

Patients should be stable on alpha-blocker therapy before beginning sildenafil treatment to reduce the risk of developing postural hypotension. Sildenafil should also be started at reduced doses (see General Precautions and Drug and Other Drug Interactions).