VIAGRA (sildenafil citrate) is indicated for the treatment of erectile dysfunction.

For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity. However, VIAGRA (sildenafil citrate) may be taken anywhere from 4 hours to 0.5 hour before sexual activity. Based on effectiveness and toleration, the dose may be increased to a maximum recommended dose of 100 mg or decreased to 25 mg. The maximum recommended dosing frequency is once per day.

The following factors are associated with increased plasma levels of sildenafil: age > 65 (40% increase in AUC), hepatic impairment (e.g., cirrhosis, 80%), severe renal impairment (creatinine clearance < 30 mL/min, 100%), and concomitant use of potent cytochrome P450 3A4 inhibitors [ketoconazole, itraconazole, erythromycin (182%), saquinavir (210%)]. Since higher plasma levels may increase both the efficacy and incidence of adverse events, a starting dose of 25 mg should be considered in these patients.

Ritonavir greatly increased the systemic level of sildenafil in a study of healthy, non-HIV infected volunteers (11-fold increase in AUC, see DRUG INTERACTIONS) Based on these pharmacokinetic data, it is recommended not to exceed a maximum single dose of 25 mg of VIAGRA (sildenafil citrate) in a 48 hour period.

VIAGRA (sildenafil citrate) was shown to potentiate the hypotensive effects of nitrates and its administration in patients who use nitric oxide donors or nitrates in any form is therefore contraindicated.

When VIAGRA (sildenafil citrate) is co-administered with an alpha-blocker, patients should be stable on alpha-blocker therapy prior to initiating VIAGRA (sildenafil citrate) treatment and VIAGRA (sildenafil citrate) should be initiated at the lowest dose (see DRUG INTERACTIONS).

VIAGRA® (sildenafil citrate) is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to the nominally indicated amount of sildenafil as follows:

Recommended Storage: Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature].

Distributed by: Pfizer Labs, Division of Pfizer Inc, NY, NY 10017. Revised January 2010

Last reviewed on RxList: 1/3/2011
This monograph has been modified to include the generic and brand name in many instances.