Opportunistic Infections & Other Complications: Toxoplasmosis


Opportunistic Infections & Other Complications: Toxoplasmosis

Seattle Treatment Education Project (STEP) Perspective, Vol. 5, No. 2 - July 1993 * 127 Broadway E. Ste 200 Seattle, WA 98102
Laury McKean, RN

The biggest news in toxoplasmosis at the conference concerned the use of TMP-SMX for primary prophylaxis. Although this really is not news to most of us, the data is finally available to confirm what has been suspected for some time now. Dr. Tournerie presented data on a study conducted in which investigators looked at the 597 individuals enrolled in the Alpha trial in France. This population was chosen because the seroprevalence of toxoplasmosis was high (73%). Of the 499 individuals who had never experienced toxoplasmosis, 80 individuals who received TMP-SMX for PCP prophylaxis were compared with the 419 other participants who received mainly aerosolized pentamidine for PCP prophylaxis who served as controls. Only one of the 80 individuals (1.3%) in the TMP-SMX group got toxoplasmosis compared with 49 cases (11.7%) in the control group (WS-B13- 2). The protective effect of TMP-SMX against toxoplasmosis was also reported on in several posters presented at the conference (PO-B10-1443, PO-B10-1476, PO-B10-1505, PO-B10-1518).

Dr. Shumann presented data of a German study comparing dapsone/pyrimethamine with Fansidar for primary prevention of toxoplasmosis. Twenty-three individuals received 100 mg of dapsone and 50 mg of pyrimethamine twice a week. Twenty-nine individuals received 500 mg of sulfadoxine and 25 mg of pyrimethamine twice a week. The median follow- up period was 14 months. Two individuals in both the dapsone/pyrimethamine group and the Fansidar group got toxoplasmosis, however non-compliance was documented by serum blood levels in both the individuals in the Fansidar group, explaining the two cases in this group. Two additional individuals in the dapsone group discontinued therapy due to adverse reactions and none of the individuals discontinued therapy in the Fansidar group. Fansidar is widely used in Europe however it is currently rarely used in the United States because many physicians fear a severe allergic reaction called Steven Johnson's syndrome which can occur (although extremely rare) with the drug (WS-B14-3).

Numerous posters presented data showing very positive results with the use of atovaquone for treatment of cerebral and ocular toxoplasmosis which did not respond to conventional therapies or when other therapies could not be tolerated (PO-B10-1449, PO-B10-1451, PO-B10-1453, PO-B10-1481, PO-B10-1498, PO-B10-1507, PO-B10-1504). All of the studies concluded that atovaquone was effective and well tolerated. However, in some of the studies individuals were switched to maintenance therapy with pyrimethamine which was not effective in preventing recurrence. Therefore consideration should be given to indefinate therapy with atovaquone (PO-B10-1507, PO-B10-1507).

An interesting poster presentation was on seven individuals with toxoplasmosis who were treated with tetracycline derivatives. The individuals were given either doxycycline alone (four mg/kg/day), minocycline alone (four mg/kg/day), or minocycline combined with pyrimethamine. All seven individuals experienced complete alleviation of symptoms as well as shrinkage of brain lesions by at least 75%. There were no significant toxicities. Three of the individuals died of unrelated AIDS complications and the two who were autopsied showed no evidence of CNS or systemic toxoplasmosis. The other four individuals are still asymptomatic, two on minocycline alone and two on minocycline and pyrimethamine. The maximum follow-up time to date is 15 months (PO-B10-1427).
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Always watch for outdated information. This article first appeard in 1993. This material is designed to support, not replace, the relationship that exists between you and your doctor.

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This information is designed to support, not replace, the relationship that exists between you and your doctor.
©1993. AEGIS.