Scientific Poster Session I - Case Reports

Abstract

Case: A 60-year-old El Salvadoran man with a heart transplant for Chagas cardiomyopathy on tacrolimus, mycophenolate, and prednisone was evaluated for abdominal wall induration and left knee erythema. Trypanosomes were histologically identified on skin biopsy. Inpatient oral benznidazole 5 mg/kg every 12 hours was started after obtaining the medication from a facility in Boston. Due to a concomitant bacterial infection, mycophenolate was held and the tacrolimus goal trough range was reduced from 12-15 to 10-12 ng/mL. The tacrolimus dose was initially reduced by 50% and its levels monitored daily given potential benznidazole-tacrolimus interactions. Tacrolimus levels dropped to below target range, and the dose needed gradual upward adjustment. Cutaneous Chagas disease reactivation resolved after 60 days of benznidazole, with nausea and weight loss as the main adverse effects

Discussion: Because azole antifungals inhibit the metabolism of tacrolimus, thereby increasing its blood levels, it is imperative to consider that similar effects may occur with other azole agents such as benznidazole. Tacrolimus itself can decrease benznidazole excretion, leading to higher serum levels and more adverse effects. Tacrolimus levels can vary during benznidazole therapy, necessitating frequent dosage adjustments.

Conclusion: Benznidazole treats cutaneous Chagas disease reactivation after transplantation, but its complex interactions with tacrolimus mandate close monitoring of tacrolimus levels and associated adverse effects of both drugs.

Presenting Author

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