Intravenous pentamidine is effective as second line Pneumocystis pneumonia prophylaxis in pediatric oncology patients.

BACKGROUND: Pneumocystis jirovecii, formerly carinii, pneumonia (PCP) poses a life-threatening risk to oncology patients. The use of trimethoprim-sulfamethoxazole (TMP-SMZ) prophylaxis virtually eliminates the risk of infection; however, many patients cannot tolerate TMP-SMZ. We performed a retrospective analysis to determine the PCP breakthrough rate in pediatric oncology patients receiving intravenous pentamidine as second line PCP prophylaxis.

PROCEDURE: We conducted a retrospective chart review of pediatric oncology patients who received intravenous pentamidine from 2001 to 2006 at our institution. The diagnosis, age and bone marrow transplant (BMT) status were determined. A subset of patients had review of their records to determine the justification for discontinuing TMP-SMZ. Children who developed symptoms of pneumonia with a clinical suspicion of PCP underwent bronchoscopy, allowing for identification of Pneumocystis.

RESULTS: A total of 232 patients received 1,706 doses of intravenous pentamidine and no toxicities were identified. The main reasons for discontinuing TMP-SMZ were bone marrow suppression and drug allergy. Three children developed PCP, equating to a breakthrough rate of 1.3%. Two of these children had undergone BMT (1.9% breakthrough rate) and both were under the age of two (6.5% breakthrough rate).

CONCLUSIONS: The use of intravenous pentamidine as PCP prophylaxis results in a breakthrough rate of 1.3%. TMP-SMZ is the first choice for PCP prophylaxis. However, when necessary, the use of intravenous pentamidine has an acceptably low failure rate, even in high-risk BMT patients. Other options should be considered for children less than 2 years of age.