Efficacy and safety of a low-dose sulfamethoxazole/trimethoprim regimen in preventing pneumocystis pneumonia: A retrospective study using a large-scale electronic medical record database.

Introduction: Sulfamethoxazole/trimethoprim (ST) is a first-line drug for preventing pneumocystis pneumonia (PCP). Several small-scale studies have suggested the usefulness of the low-dose regimen of ST (200/40 mg/day) over the standard-dose one (400/80 mg/day). Thus, this study aimed to investigate the efficacy and safety of low-dose and standard-dose regimens of ST in preventing PCP in patients with non human immunodeficiency virus infection using a large-scale electronic medical record database.