TRIMETHOPRIM/SULFAMETHOXAZOLE FAVORED OVER AEROSOLIZED PENTAMIDINE
Executive Summary
TRIMETHOPRIM/SULFAMETHOXAZOLE FAVORED OVER AEROSOLIZED PENTAMIDINE for prevention of both primary and secondary cases of Pneumocystis carinii pneumonia in people with AIDS in new guidelines that will be issued by the Public Health Service's special task force on PCP, Henry Masur, National Institute of Health Clinical Center, told a recent meeting of the National Institute of Allergy and Infectious Diseases' AIDS Clinical Trials Group. The guidelines are expected to be issued sometime in the next month, Masur said Dec. 3. The guidelines recommend that people with AIDS with an absolute CD4 count of less than 300 cells be treated with 80 mg trimethoprim/40 mg sulfamethoxazole four times daily to prevent onset or recurrence of PCP. Patients with "only a minor intolerance to TMP/SMX should be rechallenged" at least once before switching them to pentamidine, Masur added. Masur explained that the decision to revise the task force's original 1987 guidelines, which recommended primary and secondary treatment with aerosolized pentamidine, "was based on the results of ACTG 021 . . . and a series of other clinical trials" demonstrating the superior efficacy of trimethoprim therapy. A recently completed, head-to-head trial comparing the efficacy of the two PCP treatments, ACTG 021 demonstrated that the risk of recurrent PCP was 3.25 times greater among patients receiving aerosolized pentamidine and AZT than among patients receiving the less expensive TMP/SMX in combination with AZT ("The Pink Sheet" Sept. 9, p. 9). TMP/SMX is marketed by Hoffmann-La Roche as Bactrim, Burroughs Wellcome as Septra and in generic versions. The ACTG's working group on PCP prophylaxis plans to follow up protocol 021 with a series of additional trials (ACTG 081, ACTG 173 and ACTG 108) testing the efficacy of other, less prominent PCP prophylactics. Some of the therapies to be tested include dapsone, steroids and a new compound developed by the Walter Reed Army Medical Center, WR6026. All of these ACTG trials are currently in the protocol planning or enrollment phases.