Clindamycin-primaquine for pneumocystis jiroveci pneumonia in renal transplant patients.

Background: Trimethoprim/sulfamethoxazole (TMP/SMX) is considered first-line therapy for pneumocystis jiroveci pneumonia (PCP) in renal transplant patients. Alternatives have not been formally studied. Clindamycin-primaquine (C-P) is effective in HIV-associated PCP, but data in renal transplant patients are lacking.
Patients and Methods: Retrospective cohort study of 57 consecutive renal transplant patients who developed PCP and were treated with C-P (n = 23) or TMP/SMX (n = 34).
Results: A non-significantly higher failure rate was observed in patients on C-P due to lack of efficacy (30.4 versus 20.6%, p = 0.545). The difference was more pronounced in severe PCP (60 versus 37.5%, p = 0.611) and a significantly lower efficacy of C-P was seen when used as salvage therapy. The two patients who had received C-P after not responding to TMP/SMX failed this regimen, but all seven patients who had failed initial treatment with C-P and had been switched to TMP/SMX were cured (p = 0.028). No treatment-limiting adverse reactions were reported for patients on C-P while six patients (17.6%) on TMP/SMX developed possibly related treatment-limiting toxicity (p = 0.071). However, in only two patients adverse events were definitely related to TMP/SMX (5.9%).
Conclusions: Clindamycin-primaquine appears to be safe and well tolerated for treating PCP in renal transplant patients but is probably less effective than TMP/SMX, the standard regimen. However, our data indicates that C-P represents an acceptable alternative for patients with contraindications or treatment emergent toxicities during TMP/SMX use. Notably, TMP/SMX was also acceptably tolerated in most patients. TMP/SMX remains an effective salvage regimen in case of C-P failure.