A Bayesian Approach to Assessment of Adverse Drug Reactions: Evaluation of a Case of Fatal Anaphylaxis

Abstract

A case of unexplained sudden death in a previously healthy 42-year-old woman is analyzed using the Bayesian approach. Autopsy findings were consistent with anaphylaxis, which appeared to have occurred one to three hours after a tooth extraction procedure. Four candidate drugs are considered in the analysis: zomepirac, lidocaine, and two doses of penicillin V (one taken before and the other after the dental procedure). The analysis shows that each of the four candidate drugs, if considered alone, would be a likely cause of sudden death in this case. Despite the fact that lidocaine is the only one of the four known to have been taken (from the case summary), the drug with the highest posterior odds, by far, is zomepirac. Although this result might at first seem counterintuitive, the initial (prior) uncertainty that the drug had been taken preceded the knowledge that the patient did indeed die suddenly from apparent anaphylaxis without another drug or nondrug cause of comparable likelihood.