[Early recurrence of pneumocystis pneumonia post trimethoprim-sulfamethoxazole therapy that developed after chemotherapy for follicular lymphoma].

A 75-year-old man was treated with bendamustine-containing chemotherapy for follicular lymphoma. Trimethoprim-sulfamethoxazole (TMP-SMX) for pneumocystis pneumonia (PCP) prophylaxis was discontinued at the last course of the chemotherapy. However, the patient developed PCP 6 months after the last course, and treatment with TMP-SMX (480 mg/day) was initiated. The TMP-SMX dose was reduced after 3 weeks of treatment. However, PCP recurred 6 days after dose reduction. Increasing the TMP-SMX dose to the therapeutic dose improved PCP. The dose was reduced to a maintenance dose after 7 weeks of the therapeutic dose of TMP-SMX treatment, and PCP did not recur thereafter. This case demonstrated that the early recurrence of PCP after appropriate treatment duration in immunocompromised conditions after chemotherapy, including bendamustine, may require prolonged treatment.