Deciphering erectile dysfunction drug trials

Purpose: Erectile dysfunction affects more than 20 million men in the United States. Currently, there are at least 10 novel erectogenic agents in development. It is incumbent on clinicians and especially urologists to be facile in interpreting data from drug trials investigating such medications. Materials and Methods: A comprehensive review of the literature addressing novel Food and Drug Administration approved erectogenic drugs was conducted using MEDLINE to highlight the key points in the analysis of data arising from these trials. Results: The major points for analysis include trial design, patient population studied, end points used and adverse event profile. The patients enrolled in erectile dysfunction drug trials should be representative of the general erectile dysfunction population. Assessment of the population includes defining baseline erectile dysfunction severity, co-morbidity profiles and concomitant medication use. Defining clinically meaningful end points is difficult. Several validated questionnaire instruments are available, the most commonly used being the International Index of Erectile Function. Much of the data gathered are based on this self-report inventory. Factors relating to adverse events include frequency of events-per patient and per administration rates-and severity and duration of side effects. Conclusions: Several key factors in trial design, patient enrollment and outcome analysis need to be assessed to interpret accurately the data generated from erectile dysfunction drug trials.