Comparison of FDA reports of patient deaths associated with sildenafil and with injectable alprostadil.
BACKGROUND
Sildenafil (Viagra) has been linked to 240 deaths (128 verified, 112 unverified) reported to the Food and Drug Administration (FDA) during 7.5 months of availability, and to 522 reported deaths after 13 months of availability. To date, no updated information about FDA-reported deaths has emerged, and no comparative analyses have been published.


OBJECTIVE
To compare the mortality rates between sildenafil and injectable alprostadil, both of which are used exclusively for treating erectile dysfunction.


METHODS
A comparison of the number of deaths per filled prescriptions reported to the FDA involving sildenafil and injectable alprostadil was undertaken to perhaps provide further insight into this issue. Materials included FDA statements on sildenafil adverse event reports to the FDA involving sildenafil and injectable alprostadil, and data on prescriptions filled for sildenafil and injectable alprostadil.


RESULTS
The number of deaths per prescriptions filled reported in association with sildenafil was significantly greater (5.15-6.28 times) than in association with injectable alprostadil.


CONCLUSIONS
Previous explanations for sildenafil-associated deaths have been based on the expected attrition within the population of men with erectile dysfunction and its commonly associated disorders, the physiologic stress of renewed sexual activity, and a pharmacologic effect of sildenafil. The results of this analysis may indicate that a pharmacologic effect of sidenafil is responsible for these deaths. However, other factors may also explain these findings: a greater frequency of reporting of sildenafil-associated events by physicians, a difference in the populations using these two drugs, or the number of prescriptions filled may not accurately reflect actual exposure.


CONCLUSIONS
Further study should be undertaken to clarify the issues associated with sildenafil-related deaths. In the meantime, reasonable precautions might be considered in prescribing sildenafil, such as initiating treatment with a low test dose of sildenafil.
Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, USA. jacohen@ucsd.edu
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Cohen
D000527:Alprostadil / Q000008:administration & dosage / Q000009:adverse effects*; D007172:Erectile Dysfunction / Q000150:complications*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D009026:Mortality; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D010879:Piperazines / Q000008:administration & dosage / Q000009:adverse effects*; D016012:Poisson Distribution; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D014481:United States; D014486:United States Food and Drug Administration; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects*
D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate; D000527:Alprostadil