Low-dose trimethoprim-sulfamethoxazole treatment for pneumocystis pneumonia in non-human immunodeficiency virus-infected immunocompromised patients: A single-center retrospective observational cohort study.

BACKGROUND/PURPOSE: The efficacy of low-dose trimethoprim-sulfamethoxazole (TMP-SMX) may be acceptable for the treatment of pneumocystis pneumonia (PCP) in non-human immunodeficiency virus (HIV)-infected patients, with a low incidence of adverse reactions. This study is aimed to evaluate the efficacy and safety of such a regimen for the treatment of non-HIV PCP.

METHODS

We retrospectively enrolled 24 consecutive patients diagnosed with non-HIV PCP who were treated with low-dose TMP-SMX (TMP, 4-10 mg/kg/day; SMX, 20-50 mg/kg/day). Data of the conventional-dose treatment were used as reference. The primary endpoints were the 30- and 180-day survival rates from the day of treatment, and secondary endpoints were the incidence of each adverse reaction and dropout rate from the initial TMP-SMX regimen. The survival rate was estimated using the Kaplan-Meier method with 95% confidence interval (CI).

RESULTS

The median age of patients was 72 years (54.2% men), and connective tissue disease was the most frequent underlying disease (66.7%) in the low-dose group. The 30- and 180-day survival rates were 95.8% (95% CI: 88.2-100.0%) and 91.0% (95% CI: 79.9%-100.0%), respectively, in the low-dose group and 69.0% (95% CI: 54.0%-88.0%) and 51.5% (95% CI: 36.1%-73.4%), respectively, in the conventional-dose group. The total adverse reaction rate was 58.3% in the low-dose group and 72.4% in the conventional-dose group. A total of 75.0% of patients in the low-dose group and 31.0% in the conventional-dose group completed treatment with the initial regimen.

CONCLUSION

Low-dose TMP-SMX may be a treatment option for patients with non-HIV PCP.