A Case Report of Fatal Desmethyl Carbodenafil Toxicity.

We present the case report of a 34-year-old Hispanic male who was found unresponsive in the carport of his residence. Surveillance video footage from a security camera showed that he collapsed as he was walking to his vehicle. The decedent had no medical history and no history of illicit drug use. Initial toxicology testing revealed no alcohol or illicit drugs. Autopsy findings indicated a need for additional toxicological analysis due to a lack of trauma and the paucity of pathophysiologically significant natural disease. Liquid chromatography time-of-flight mass spectrometry of postmortem blood revealed the presence of two large peaks corresponding to desmethyl carbodenafil, an unapproved sildenafil analogue and its hydroxy metabolite. Species that are probable desmethyl and hydroxydesmethyl metabolites of desmethyl carbodenafil were also found. The mass and retention time of the parent compound in the decedent's sample were matched to those of a commercial standard. Based on this preliminary match, a method was developed and validated to quantify desmethyl carbodenafil in human blood. This is the first known case of fatal intoxication by desmethyl carbodenafil, a phosphodiesterase-5 inhibitor that is not approved for use in the United States. Over the past several years, retailers have issued voluntary recalls for dietary supplements marketed as sexual performance enhancers on the basis that these supplements may contain undeclared desmethyl carbodenafil.