Safety and efficacy of reduced-dose pentamidine as second-line treatment for HIV-related pneumocystis pneumonia

Abstract

Objectives: Parenteral pentamidine isethionate (PM) 4 mg/kg/day is recommended as an alternative therapeutic regimen after failure of first-line treatment for pneumocystis pneumonia (PCP). However, the dose is often reduced to 3 mg/kg/day in clinical settings because of high rates of adverse events and drug toxicity. Although considered equally efficacious, this lower dose has not been well evaluated.

Methods: This was a single-center, retrospective cohort study that analyzed 75 patients with HIV-PCP who were treated with trimethoprim-sulfamethoxazole, but discontinued treatment because of treatment failure or adverse events; they were then administered 3 mg/kg/day of intravenous PM as a salvage therapy. The primary outcomes were the regimen completion rate with the reduced PM dose.

Results and conclusions: In total, 40 (53.3%) of the eligible patients completed PCP therapy with reduced-dose PM salvage treatment. The overall survival rate of PCP was 73 (97.3%). The median duration of second-line PM treatment was 8.0 days (interquartile range: 6.0-10.0). Although, the adverse events with reduced-dose PM were observed in 41 (54.7%), including 35 treatment-limiting adverse events, grade 3 or 4 adverse events occurred in only three patients (thrombocytopenia, one patient; neutropenia, two patients). Life-threating adverse events, such as hypoglycemia and arrhythmia, were not observed with reduced-dose PM. Salvage therapy with reduced-dose PM for patients with HIV-PCP is relatively safe and effective; moreover, life-threating adverse events did not occur. This therapy could be recommended for patients with HIV-PCP who fail to respond to first-line treatment with trimethoprim-sulfamethoxazole.

Keywords: Drug toxicity; Human immunodeficiency virus; Hypoglycemia; Pentamidine; Pneumocystis pneumonia.