A variety of side effects have been reported for these drugs. These adverse effects can be grouped into the 5 groups listed in section B. Generally, once patients stop taking Bactrim/Septra (B/S) symptoms of allergy/toxicity go away. Patients can be switched to intravenous pentamidine, the new drug Mepron(R) (atovaquone, 566C80) or several other drugs to complete anti-PCP therapy.
Once the patient has recovered some doctors try to help them reduce their sensitivity to the offending drug. At first doctors may give them very small doses of Bactrim/Septra (sometimes in liquid form) and over a period of weeks gradually increase their dose until it reaches the strength needed for prevention or treatment. This process is called desensitization. Should allergic reactions occur, doctors may use Tylenol and the antihistamine Benadryl and prednisone to reduce symptoms. Desensitization will not work for every patient. A schedule for desensitization has already appeared in TreatmentUpdate 24.
Researchers in Australia have been working at predicting which of their patients will develop allergies to Bactrim/Septra. Unfortunately these allergies can happen at any stage of HIV infection and more accurate ways of predicting this are needed. In separate studies in the USA and Zaire, black patients seem to be less likely than white patients to have skin rashes and reactions to B/S. In patients with liver disease, B/S may decrease the ability of kidneys to remove AZT from the blood. Other researchers think that supplements of anti-oxidants such NAC may help reduce these allergic reactions.
Other drugs containing sulpha such as dapsone, sulfadoxine (Fansidar(R)) and Sulphadiazine can also cause adverse reactions in people with HIV infection. See the section on drugs for toxo for more information on Fansidar and pyrimethamine. People of color may also get more side effects when given dapsone than white people.
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Copyright © 1993 - 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
This information is designed to support, not replace, the relationship that exists between you and your doctor.