Salvage therapy with clindamycin/primaquine for Pneumocystis carinii pneumonia

Clindamycin/primaquine is effective for treating mild-to-moderate cases of Pneumocystis carinii pneumonia (PCP) in patients with AIDS. We retrospectively reviewed our experience with this combination among patients in whom conventional therapy had failed or was not tolerated. Twenty-six patients who experienced 28 episodes of PCP received salvage therapy with clindamycin/primaquine at two university-affiliated medical centers. Clindamycin was administered intravenously, (usually 900 mg every 8 hours), after which oral therapy was instituted. Primaquine (30 mg) was given orally to all patients except three; two of these patients received 15 mg of the drug daily and another 30 mg of drug on alternate days. In 11 of the episodes, the patients received clindamycin/primaquine as initial therapy for PCP because of previous intolerance of conventional therapy. In 13 of the episodes, conventional therapy had failed or the patients were unable to tolerate the regimen, while in four episodes conventional therapy failed and the patients were unable to tolerate their therapeutic regimens. Twenty-four (86%; 95% confidence interval, 73%-99%) of 28 episodes were successfully treated with clindamycin/primaquine. The most common adverse effect was the development of an erythematous rash. Clindamycin/primaquine appears to be an attractive alternative for patients in whom standard therapy for PCP has failed or cannot be tolerated.