Her T-cell count fell anyway in 1992. T cells allow the body to fight infections. Healthy individuals have around 800 to 1,300 in a microliter, or about a teaspoon of blood. A person with AIDS has T-cell numbers below 200.
With such low levels, doctors diagnosed her as having AIDS, and said she needed additional medication. Her doctor recommended she take ddI, another reverse transcriptase inhibitor; an antibiotic to prevent pneumonia; an antifungal, since she was having chronic yeast infections, and an antidepressant.
"You had to grind ddI up like Alka-Seltzer, and it just tasted awful," says Lewis-Thornton. She took the antidepressant because she says, "it was hard to cope."
By 1993, she had her first bout with pneumocystis pneumonia and had become extremely skinny — wasting syndrome is another symptom of AIDS. Her doctor stopped her AZT and ddI, gave her two new antivirals, an appetite stimulant and continued the antifungals, the antibiotic and the antidepressant.
But in 1996, she had to be hospitalized with pneumocystis pneumonia and she received yet a new antibiotic to fight yet another opportunistic infection called mycobacterium avium complex.
Protease Inhibitors: A Major Advance
The year 1998 was a turning point. Lewis-Thornton had suffered two more bouts with pneumonia needing hospitalization and was very thin. But a new class of drug, the so-called protease inhibitors, approved in 1996, made a big difference.
"I got better," says Lewis-Thornton. "I gained weight. My T-cell numbers increased. My viral lode became non-detectable. My energy was improved. I could go shopping and cook when before I only had enough strength to do either one."
She was able to stop taking half her drugs, keeping to three antivirals, including the protease inhibitor, and one antibiotic.
While Lewis-Thornton now lives with the side effects of the current drugs she takes, her experience highlights the problems with treatment regimens for AIDS patients.
Half the people who try the medications do not respond to them and the side effects, such increased cholesterol levels and diabetes, may be so severe that the risk of taking the drug outweighs their benefits.
Lewis-Thornton experienced the protease inhibitor side effect that causes the redistribution of fat on the body. She gained enough weight to become a size 6, but the drug increased her girth on the upper part of her body to a size 12.
Taking the drugs also is not trivial. Some people take a dozen pills at different times during the day. Forgetting a pill can be lethal. During the time of a missed dose, a mutant virus can grow within a person's body that no longer responds to the medication.
Some current formulations of AIDS medications include more than one drug, making it easier for patients to take.
New Drugs in Development
While the reverse transcriptase and protease inhibitors affect two different aspects of the life cycle of the virus, new drugs in development take aim at other weak spots.
Reverse transcriptase inhibitors, for example, prevent the virus from making DNA out of the viral RNA. Protease inhibitors block the enzyme in the virus from breaking apart long strands of viral proteins to make smaller active HIV proteins that comprise the viral particle.
A new type of drug tries to stop the virus from fusing with the protein on the surface of T-cells, one of the earliest steps in the infection process.