Johns Hopkins University researchers are starting two studies that explore ways of extending to AIDS patients the benefits of a life-prolonging medication called Bactrim.
The sulfa-based antibiotic is used to prevent and treat pneumocystitis carinii pneumonia (PCP), an opportunistic infection that preys on people with severely damaged immune systems.
Unlike AZT, an anti-viral treatment prescribed to slow the progress of the AIDS virus itself, Bactrim is used to treat the complications that arise when the virus reaches an advanced stage. And, in the absence of a miracle AIDS drug, many doctors call Bactrim the most broadly effective treatment available for people in the later stages of infection with human immunodeficiency virus.
The catch is that about half of them cannot tolerate the medication.
"Among the drugs we've researched to use in treating HIV and AIDS, the use of Bactrim is perhaps the single greatest achievement," said Dr. Judith Feinberg, director of the studies at the Johns Hopkins Medical Institutions.
And "of all the advances we've made in the management of HIV disease in the past few years, nothing has had the impact in terms of prolonging life that preventing PCP has."
The two studies will investigate the use of alternatives to Bactrim and a method of building patients' tolerance to the drug. Initially used to treat leukemia patients suffering from PCP, Bactrim long has been among the arsenal of drugs used to treat AIDS patients with PCP.
But in the late 1980s, doctors realized that if the drug was prescribed to patients before they had PCP, the drug could fend off the pneumonia.
During the 1980s, the pneumonia was the first sign of the onset of acquired immune deficiency syndrome in 65 percent of HIV-positive patients. That figure has dropped by about 20 percent, said Dr. Feinberg.
"When I give lectures to health care providers who care for people with AIDS, I tell them that if your patient only takes one pill a day that pill should be Bactrim," Dr. Feinberg said.
However, in many patients, Bactrim causes severe rashes, fevers and upset stomachs, she said.
In the first Hopkins study, AIDS patients who cannot tolerate Bactrim will be treated instead with one of two nonsulfa-based drugs called Dapsone and Atovaquone.
Volunteers for this study must come to Hopkins for clinical examinations every four months and to pick up medicine every two months for as long as four years, she said. In the second trial, which will run three months, patients who have never taken Bactrim will be administered small doses of that drug, then gradually increasing amounts to see if a tolerance can be developed.
For information about the studies, call (410) 614-0926.