Perfection Required By HIV Drugs

HIV patients must take pills perfectly to achieve full suppression of virus

(RxWiki News) It's a challenge to take medication perfectly every day, especially if you're on it for the rest of your life. So is it a big deal if you slip up every once in a while?

For HIV patients, it is.

According to a new study, patients must maintain their medication perfectly – with no exceptions – in order to completely ensure that the virus is not spreading in their cells.

"Take your HIV medications as prescribed."

The study was conducted by a team of researchers in the Netherlands, at the Laboratory of Experimental Virology. It was published in the Journal of Infectious Diseases.

Antiretroviral therapy (ART), or treatment with a HIV-fighting drugs, has had widespread success in controlling the virus and helping people live long lives.

But there are differences in the levels of success that come with ART. A patient could have undetectable levels of HIV in their bodies, but the virus is still able to replicate within infected cells.

Completely suppressing the virus means that the virus is essentially inactive. It doesn't mean the patient is cured, but it is the ideal result of ART.

According to the study, it's been widely assumed that even if a patient misses a few pills every once in a while, viral suppression can still be achieved. The statistic is that adherence to the medication regimen up to 70 percent of the time with certain powerful drugs is good enough for viral suppression.

Despite this accepted wisdom, the study authors said, it's unknown whether the virus is actually suppressed at these levels. Previous tests had been based on changes in the viral load in plasma, not within the cells themselves.

To find out whether this different type of test came up with a different result, the researchers conducted a long-term study on 40 patients taking ART. They monitored their adherence to their medications.

When they tested the participants' viral loads, they looked at two biological markers within the cell that would give them a measure of how much of the virus was present.

Most of the participants (58 percent) had perfect adherence. Patients who did not have perfect adherence had a median of 82 percent adherence.

The viral levels detected by the regular test were the same, but the levels found by a more sensitive biomarker, called usRNA, saw some changes. Those who didn't have perfect adherence – even those who had improved their adherence to 100 percent over time - had more HIV-associated usRNA in their cells.

This means that to truly block the replication of the virus, patients need to have perfect adherence to ART over their entire lifetimes. That's a challenge.

On the other side of the coin, regular non-adherence to HIV drugs is a major problem in fighting the virus. People who interrupt their treatment for days or months at a time can develop and spread a dangerous drug-resistant form of HIV.

The study was published in September 2012.

Review Date: 
September 24, 2012