The FDA Adverse Event Reporting System (FAERS) is a spontaneous reporting system for adverse events associated with pharmaceutical drugs. In this study, we aimed to assess the adverse events and patient outcomes associated with the current clinical treatment of Toxoplasma gondii infections using real-world data reported to FAERS.

Toxoplasma gondii is a highly prevalent opportunistic pathogen that frequently causes neurologic disease. First-line treatments for toxoplasmosis include antifolate and antibiotic drugs. Previous studies of adverse events associated with these treatments have focused on individual regimens in case reports or specific populations. Adverse events and outcomes associated with the treatment of T. gondii infections in patients with various health backgrounds have not been characterized.

Data submitted to the FAERS between 2013 and 2019 were retrieved and analyzed. Reporting odds ratio of death was calculated for the drugs having > 25 reports of adverse outcomes. The adverse event profiles for the same drugs were analyzed and the reporting odds ratio was calculated relative to all other drugs used in the treatment of Toxoplasma infections.

There were 503 cases reporting the treatment of Toxoplasma infections in the FAERS database. Death (DE) was the adverse outcome in 102 reports, of which 23 (22.5%) anti-Toxoplasma drugs were listed as the primary suspect drug (PS). Clindamycin (2.04; 1.07-3.90) followed by pyrimethamine (1.53; 0.99-2.36) were the most likely to be associated with death. Adverse events analysis suggest that sulfonamide formulations may have a less favorable safety profile. 

Our study represents the first real-world analysis of adverse outcomes and events associated with the treatment of Toxoplasma infections. Our findings support the need to better understand the current first-line agents for Toxoplasma infections, in addition to underscoring the need to identify safer regimens.