Is the sildenafil product information adequate to facilitate informed therapeutic decisions?

BACKGROUND: Optimal therapeutics and the prevention of adverse drug effects begin with complete information. When new drugs are released, the manufacturer's product information is the main and often only readily available source of drug information and, therefore, greatly influences treatment strategies. Thus, it is vital that the information in the package insert is not only complete, but also as relevant as possible for the great diversity of patients that physicians encounter. OBJECTIVE: To review the product information for sildenafil for comprehensiveness and accuracy, with respect to whether the information is sufficient to facilitate optimal therapeutics and to prevent avoidable adverse events in the wide diversity of patients with erectile dysfunction seen in clinical practice. DATA SOURCES: Sildenafil package inserts, unpublished information provided by the manufacturer, Food and Drug Administration reports, and articles retrieved through MEDLINE through March 2000. DATA SYNTHESIS: Deficiencies or inaccuracies persist in the sildenafil product information regarding sildenafil's effects on blood pressure; potential drug interactions with cimetidine, protease inhibitors, some antihypertensive drugs, alcohol, and drugs that may competitively inhibit cytochrome P450 pathways; and recommended sildenafil doses for older patients. CONCLUSIONS: For physicians to practice optimal therapeutics, adequate, clinically relevant drug information is required. Several brief changes and additions in the sildenafil product information would assist physicians in making therapeutic decisions regarding the use of sildenafil in a very diverse patient population and in avoiding preventable adverse events.