ROXITHROMYCIN FAILS IN ADVANCED TOXOPLASMOSIS

On March 10, AIDS TREATMENT NEWS reported that roxithromycin had been found effective in treating toxoplasmosis in mice, and had also been found to reach extremely high concentration in brain tissue when the drug was given to humans scheduled to undergo neurosurgery (so that the brain concentration could be measured). This preliminary work suggested that roxithromycin should be tried as a treatment for toxoplasmosis. We could only find one human case where the treatment had been tried, however, and the result was inconclusive. No trials were planned in the United States, where 20,000 to 40,000 cases of toxoplasmosis have been predicted by 1991 (Luft and Remington, "Toxoplasmic Encephalitis", The Journal of Infectious Diseases, January 1988). We mentioned that we had heard a report that a small trial would soon begin in France.

At the Montreal conference, physicians from a hospital in Paris reported that they gave three times the usual dose of roxithromycin to eight patients who could no longer tolerate pyrimethamine/sulfadiazine (P/S), the conventional treatment for toxoplasmosis (poster # W.B.P.29 in the conference abstracts). However, symptoms of toxoplasmosis reappeared after 28 to 45 days of treatment. In four of these eight patients, P/S treatment could be started again, and it was successful. The conclusion was that the roxithromycin was not effective.

In addition, on June 6 a French physician wrote to us that roxithromycin had been found ineffective, at least when used after cerebral abscesses had already formed, although he noted that it might prove useful earlier.