Pneumocystis jiroveci is a fungus causing pneumonia mainly among patients with an impaired immune system, such as those infected with the human immunodeficiency virus (HIV), cancer patients, following organ transplantation, patients receiving immune suppressive medications, etc. Previous evidence showed that preventive antibiotic treatment (before the onset of the disease) could lower mortality and morbidity from PCP among patients with HIV. We assessed whether this is also true for immunocompromised non-HIV patients. This review of randomised controlled trials (RCTs) found that prophylaxis with trimethoprim/sulfamethoxazole, an antibiotic effective against PCP, significantly reduced the occurrence of PCP by > 90%. The patients included in the 11 trials we identified were adults with acute leukemia or solid organ transplantation and children with acute leukemia. We found no evidence for reduction in all cause mortality.
Preventive treatment was not associated with an increased rate of adverse events.
Trimethoprim/sulfamethoxazole may be administered thrice weekly as effectively as once daily.
PCP is a rare disease. The number of patients needed to be treated with trimethoprim/sulfamethoxazole for a prolonged period of time (ranging between several weeks to three years in included trials) in order to prevent one episode of PCP infection is 15. Given the low rate of adverse events, prophylaxis should be considered for patients similar to those included in the trials.