Rezafungin as Primary Prophylaxis of Pneumocystis jirovecii Pneumonia in a Critically Ill Person Presenting with AIDS with Trimethoprim/Sulfamethoxazole Allergy: A Case Report

Primary prophylaxis of <i>Pneumocystis jirovecii</i> pneumonia (PCP) in people with HIV (PWH) and CD4+ counts <200 cells/µL using trimethoprim/sulfamethoxazole (TMP-SMX) is highly effective but often poorly tolerated. Alternative agents may have limited efficacy or availability. Although rezafungin demonstrated PCP protection comparable to TMP-SMX in animal models, human data are limited to the ongoing ReSPECT trial, and evidence in PWH is lacking. We report the first use of rezafungin as PCP prophylaxis in a PWH. A 43-year-old man presenting with AIDS (HIV-RNA 8.48 × 10⁶ copies/mL; CD4+ 20 cells/µL) was admitted with disseminated tuberculosis and multiple bowel perforations requiring urgent surgery. The postoperative course was marked by infectious and surgical complications. Antitubercular therapy and TMP-SMX prophylaxis were initiated postoperatively, followed by antiretroviral therapy (ART). Later, TMP-SMX was discontinued due to hypersensitivity. Because drug-drug interactions precluded atovaquone or dapsone and pentamidine was unavailable, rezafungin was started. No adverse events or fungal breakthrough infections occurred despite abdominal complications. Further data are needed to determine whether rezafungin represents a viable prophylactic option when standard agents are contraindicated or unavailable.