HIV Therapy: What is HAART? Video Transcript

Participants

Andrew Carr MD, Peter Reiss MD, Kathleen E. Squires MD

Summary

When people with HIV have good access to health care, they can expect to live long and well. That's because doctors have learned to combine drugs into regimens that successfully attack the virus at multiple places in its life cycle.

Webcast Transcript

ANNOUNCER: Doctors use drugs against HIV in carefully-planned combinations, known as HAART, or Highly Active Anti-Retroviral Therapy.

KATHLEEN SQUIRES, MD: We now have over 15 antiretroviral medications that are available to us. And the concept behind putting medications together is to try and shut down multiple steps in the life cycle of this virus.

ANNOUNCER: None of these drugs were available during the earliest years of the AIDS epidemic.

KATHLEEN SQUIRES, MD: The first cases of HIV infection were described in 1981 and it wasn't really until the second half of the 80s that we identified agents that were active against HIV.

ANDREW CARR, MD: The first HIV drug was AZT. AZT is a drug that stops the virus inserting itself into the genetic machinery of a human cell.

PETER REISS, MD: It's called a nucleoside analog reverse transcriptase inhibitor, or NRTI, abbreviated... It inhibits reverse transcriptase, and reverse transcriptase is an enzyme, is a protein which is in the virus particle, in the virus, which will translate RNA which is the genetic material that HIV carries in it, into DNA.

ANNOUNCER: When AZT blocks the action of the reverse transcriptase, it prevents the HIV from inserting its genetic material into the human cell, usually certain white blood cells called T cells.

PETER REISS, MD: And what was found out -- what was discovered is that particularly in patients who were already advanced, patients with AIDS, with established AIDS, is to some extent you could prevent new complications.

But, after a while it also became clear that the effect was transient.

ANNOUNCER: Over the course of several years, researchers developed other drugs like AZT.

Then, in the mid 1990s, another class of drugs became available, called Non-Nucleoside Reverse Transcriptase Inhibitors.

They, too, prevent the incorporation of viral genetic material into the host cell.

Also in the mid 1990s came the discovery of drugs called Protease Inhibitors, that work at a different point in the HIV replication cycle.

PETER REISS, MD: Protease inhibitors is different because they target a different viral enzyme which acts a later stage of the life cycle and importantly acts after this integration of DNA into the host genetic material.

ANDREW CARR, MD: Protease drugs don't stop the virus getting into your cells at all. What they do is they stop the cells producing new mature, healthy virus.

ANNOUNCER: It was only in the mid-1990s, with these many new drugs available, that doctors learned to combine three drugs at a time -- what's commonly known as HAART therapy.

This led to a dramatic change in patients' response to treatment.

KATHLEEN SQUIRES, MD: For the latter part of the 80s and until the mid-90s what we did was give patients single drugs, or then combination of two drugs. Certainly it made a difference in the lives of people who had advanced HIV infection. But the drugs just weren't strong enough in twos or in ones to be able to effectively shut off viral replication.

PETER REISS, MD: The real revolution came was the introduction of combination therapy... back in '96. I mean then it was at the end of the first year, it was very obvious that this was a major step forward compared to what we had before. To give you my personal perspective, looking at my own clinic, from '96 up till now, I think out of a patient population of about 70-80 patients, I haven't lost a single patient whereas before... at the end of the year, 50% of them would be gone.

ANNOUNCER: Choosing from among all of the available HIV drugs, and picking the right combination, can be challenging.