Ondansetron usage in HIV positive patients: a pilot study on the control of nausea and vomiting in patients on high dose co-trimoxazole for Pneumocystis carinii pneumonia.

This was an open, single centre study, to evaluate the safety and efficacy of ondansetron in the treatment of co-trimoxazole associated nausea and vomiting in AIDS patients. Sixteen patients presenting with their first episode of HIV-associated Pneumocystis carinii pneumonia (PCP) on high dose co-trimoxazole were given ondansetron 8 mg orally, every 8 h. Measurements were made from data recorded by each patient on diary cards. In this study 11 out of 16 (69%) patients on ondansetron experienced good control of emesis (2 or less emetic episodes) on their 'worst day' of therapy and 8 out of 16 (50%) of patients demonstrated good control of emesis throughout their treatment with co-trimoxazole. Good control of nausea (mild or none) was achieved in 7 out of 16 (47%) patients. A total of 7 patients were able to complete the full course of co-trimoxazole whilst on ondansetron. One serious adverse event (Stevens-Johnson syndrome) was reported and felt to be unrelated to ondansetron. If conventional anti-emetics fail to achieve control of symptoms or have unacceptable side effects, ondansetron may represent a possible alternative.