TreatmentUpdate59; Vol 7, No. 5 - May 1995
Sean Hosein

Researchers in Paris reported results from 8 men and 4 women whose average CD4+ cell count was about 100 cells. These subjects had been using Bactrim/Septra (containing 160 mg of trimethoprim and 800 mg of sulphamethoxazole) to prevent infections such as PCP/toxo (11 of them were taking 160/800 - one double strength tablet as PCP prevention). The remaining subject took a 'treatment' dose (640 mg trimethoprim/ 3200 sulphamethoxazole mg/day). Half of the subjects developed side effects within 15 days of using Bactrim/Septra. Eleven subjects had a rash without fever or [puritis].

* THE PROTOCOL

The researchers kept the subjects in hospital for 2 days so that if a life-threatening reaction to Bactrim/Septra occurred, subjects' lives could be saved. Researchers started giving subjects small doses of liquid Bactrim/Septra every 3 hours. The first dose had 0.2 mg of trimethoprim and 1 mg sulphamethoxazole. Eventually subjects would take 80 mg trimethoprim and 400 mg/day of sulphamethoxazole (both drugs) once daily. The researchers did not raise the dose of Bactrim/Septra nor did subjects receive any new drug for the first month after they had been desensitized. Subjects did not receive any antihistamines or corticosteroids.

* RESULTS

Four subjects developed side effects - rash - despite the desensitization protocol. Another 4 subjects developed side effects within the first month after being desensitized. Ten months after being desensitized only 4 subjects could continue to use Bactrim/Septra. Researchers could not understand why some subjects remained desensitized. They checked the CD4+ cell counts amongst the subjects but there were no statistically significant differences. This research team suggests that a longer period of desensitization may be more useful.

REFERENCES:

1. Bachmeyer C, Salmon D, Guérin C, et al. Trimethoprim-sulphamethoxazole desensitization in HIV-infected patients: an open study. AIDS 1995;9(3):299-300

2. Rieder MJ, Krause R, Bird LX and Dekaban G. Toxicity of sulfonamide-reactive metabolites in HIV-infected HTLV-infected, and non-infected cells. Journal of Acquired Immunodeficiency Syndromes and Human Retrovirology 1995;8(2):134-140.

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Copyright © 1995 - TreatmentUpdate. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the Editor, The Canadian AIDS Treatment Information Exchange, 555 Richmond St. West, Suite 505, Box 1104, Toronto, ON, M5V 3B1 • Phone: 416-203-7122 • Toll Free: 1-800-263-1638 • Fax: 416-203-8284  http://www.catie.ca