A Smart + Strong Site
Subscribe to:
Newsletters
POZ magazine
JOIN AIDSMEDS YouTube

Back to home » Treatment News » Top Stories

Most Popular Stories
Undetectable Viral Load Essentially Eliminates Transmission Risk in Straight Couples
FDA Approves New Single-Tablet HIV Regimen, Triumeq
Life Expectancy for Young People With HIV Is Nearly Normal
A 15-Year Jump in Life Expectancy for People With HIV
Scientists Devise Method of Snipping HIV From Immune Cells
Monkey HIV Vaccine Success Opens Door for Human Trials
HIV Combo Pill Less Toxic Thanks to New Form of Tenofovir
What's That Mean?
(just double-click it!)

If you don't understand one of the words in this article, just double-click it. A window will open with a definition from mondofacto's On-line Medical Dictionary. If the double-click feature doesn't work in your browser, you can enter the word below:

Most Popular Lessons
Aging & HIV
The HIV Life Cycle
Shingles
Herpes Simplex Virus
Syphilis & Neurosyphilis
Treatments for Opportunistic Infections (OIs)
What is AIDS & HIV?
More News

Have medical or treatment news about HIV? Send press releases, news tips and other announcements to news@aidsmeds.com.

Click here for more news


emailprint

April 27, 2011

HIV Drug Levels in Snips of Hair Predict Treatment Success

Measuring the levels of the antiretroviral (ARV) drug Reyataz (atazanavir) in snippets of hair might be the best way to predict treatment success, even among people with previous adherence problems, according to a study published in the May 15 issue of the journal Clinical Infectious Diseases. The new method could add a much-needed and more accurate way to detect people who are having a hard time taking their medication as prescribed.

Maintaining adequate levels of ARV drugs in the blood stream is key to preventing HIV from developing resistance to those drugs. That’s why good adherence—taking all drug doses on time as prescribed—is so important. In fact, the majority of the treatment failures that occur within the first year after a person starts ARV drugs for the first time are believed to be related to poor adherence.

Unfortunately, numerous studies have documented two factors that make it quite difficult to uncover and respond to adherence problems. First, most doctors are very poor at predicting which of their patients will have adherence problems. Second, most patients minimize—both to themselves and to others—the extent of their adherence challenges when their adherence is poor. Given that as few as three or four missed doses per month can allow HIV to develop drug resistance, there isn’t a big margin for error.

In previous experiments, Monica Gandhi, MD, MPH, from the University of California in San Francisco, and her colleagues with the Women’s Interagency HIV Study (WIHS) showed that looking at the levels of either Kaletra (lopinavir plus ritonavir) or Reyataz in hair samples gave a very accurate estimation of whether people had enough drugs in their system to suppress HIV. It also easily identified those struggling with adherence. Hair snippets can be an ideal measure of adherence, because they indicate how much Reyataz has been taken over a longer stretch of time, while blood levels might only indicate a single missed dose.

To expand on this earlier study, Gandhi’s team again looked at Reyataz levels in hair of 424 HIV-positive women enrolled in WIHS. This time, however, in addition to assessing the ability of hair samples to predict HIV treatment success, they also looked at whether hair sampling could help determine whether someone who formerly struggled with adherence could get his or her HIV back under control.

The majority of the women in this newer study had failed on other ARV regimens before starting their current regimen including Reyataz, and Gandhi’s team found that self-reported adherence was a very poor indicator of actual adherence among study participants. Whereas 77 percent claimed to have taken at least 95 percent of their Reyataz doses, hair sampling revealed that fewer than 20 percent had done so.

As with the previous study, Gandhi and her team found that the levels of Reyataz in hair perfectly corresponded to the percentage of women in each group who had achieved undetectable HIV levels. Only 25 percent of those with very low Reyataz hair levels and 52 percent of those with low Reyataz hair levels achieved undetectable viral loads. By comparison, 73 percent of the women with moderate Reyataz levels, 78 percent with high levels and 87 percent with very high levels achieved virological control. In fact, the women with the highest levels of Reyataz in their hair samples were 63 times more likely to achieve undetectable HIV levels than women with the lowest levels.

Gandhi’s team also found, however, that measuring hair levels offered a way to determine who would be able to get virus back under control after adherence problems were uncovered. In those women who continued to have the lowest levels of Reyataz in hair samples, less than 10 percent were able to reach an undetectable viral load. By comparison, in women who formerly struggled with adherence—whether measured by self-report, blood HIV levels or Reyataz hair levels—but who later had high Reyataz levels in hair (and presumably improved adherence), 88 percent were able to reestablish control of their HIV.

The authors are proposing that testing drug levels in hair could offer an important method to boost adherence rates and reduce the number of people who fail on their HIV regimens. One possibility would be to measure drug levels in hair soon after a person starts HIV therapy, and then to conduct a viral load test in those with the lowest levels. What’s more, Gandhi and her colleagues are thinking about the needs in resource-poor countries as well.

“We are currently working on developing a lower cost, point-of-care method of analyzing antiretroviral levels in hair for resource constrained settings to increase the feasibility of this tool,” they explain.

“The results of the analyses presented here argue for the possibility of hair antiretroviral concentrations serving as a method of HIV therapeutic drug monitoring that may increase the durability of current antiretroviral regimens in a variety of settings,” they conclude.

Search: Hair, drug levels, blood levels, adherence, Monica Gandhi, University of California in San Francisco, UCSF, Reyataz, atazanavir, Kaletra, lopinavir, ritonavir


Scroll down to comment on this story.



Name:

(will display; 2-50 characters)

Email:

(will NOT display)

City:

(will display; optional)

Comment (500 characters left):

(Note: The AIDSmeds team reviews all comments before they are posted. Please do not include ":" "@" "<" ">" in your comment. The opinions expressed by people providing comments are theirs alone. They do not necessarily reflect the opinions of Smart + Strong, which is not responsible for the accuracy of any of the information supplied by people providing comments.)

Comments require captcha.
Please enter this number for verification:

| Posting Rules



Show comments (0 total)


[Go to top]

Quick Links
About HIV and AIDS
The Cure
Lab Tests
Clinical Trials
HIV Meds
Starting Treatment
Switching Treatment
Drug Resistance
Side Effects
Disclosure
Lipodystrophy
Hepatitis & HIV
Women & Children
Fact Sheets
Treatment News
Community Forums
Blogs
Conference Coverage
Health Services Directory
POZ Magazine


    guycmh328
    Columbus
    Ohio


    Poz_Qt
    Columbus
    Ohio


    latinpozdallas
    Dallas
    Texas


    thebake
    Sioux Falls
    South Dakota
Click here to join POZ Personals!
Conference Coverage

XX International AIDS Conference
(AIDS 2014)
Melbourne, Australia
July 20 - 25, 2014


21st Conference on Retroviruses and Opportunistic Infections
(CROI 2014)
Boston, MA
March 3 - 7, 2014


7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention
(IAS 2013)
Kuala Lumpur, Malaysia
June 30 - July 3, 2013


more conference coverage

[ about AIDSmeds | AIDSmeds advisory board | our staff | advertising policy | advertise/contact us]
© 2014 Smart + Strong. All Rights Reserved. Terms of use and Your privacy.
Smart + Strong® is a registered trademark of CDM Publishing, LLC.