New method measures adherence to HIV drug prescriptions

May 14, 2001

CHAPEL HILL - Researchers have developed a more accurate way to determine how well people with HIV are sticking to their drug regimens.

The new method involves a combination of measures, including a dated record made by an electronic pill bottle cap.

The study appears May 15 in the Annals of Internal Medicine. The findings clearly show higher blood levels of HIV among patients who failed to take their antiretroviral regimen as prescribed.

"AIDS cases and deaths have dropped dramatically since new drug cocktails came on the market in the late 1990s," said Carol Golin, MD, research assistant professor of general medicine at UNC-CH School of Medicine and research associate with the UNC Cecil G. Sheps Center for Health Services Research. "But if patients aren't taking their medications all the time the virus can mutate and become resistant, and then the drugs don't work. In addition, that resistant virus can be transmitted to another person. Then that person would acquire a virus that's resistant to those drugs from the start."

The new study revealed that after taking antiretroviral drugs for six months, people with undetectable levels of HIV were taking their medication as prescribed about 85 percent of the time. But those with detectable virus blood levels were taking their pills about 66 percent of the time.

Compared to patients on other chronic medications, that's a relatively high adherence rate, according to study co-author Andrew Kaplan, MD, associate professor of medicine at UNC-CH.

"When you look at patients with high blood pressure, they typically take their medication 40 to 50 percent of the time," Kaplan said. He noted that it is difficult to get patients to take any kind of medication regularly.

Moreover, noted Kaplan, patients may take anywhere from six to 30 pills a day and may experience "a potpourri of side effects" including nausea, vomiting, headaches, rashes, and kidney stones.

"These are complex [antiretroviral] regimens, they have side effects, and they are chronic--people have to take them for life," said Golin.

In their report, the authors pointed to several limitations in measuring adherence to drug regimens. They noted that measures of drug levels in blood or urine "provide only a snapshot of behavior, are largely impractical in clinical venues and are affected by factors other than adherence." In addition, counting the pills in a patient's prescription bottle is time consuming, and patients may just throw away pills they haven't taken.

Golin and her collaborators at UNC and UCLA followed 108 HIV patients for one year. Once a month they checked medication adherence three ways. They counted the number of pills remaining in the patients' medicine bottles. They asked patients how well they had followed the regimen.

But the "backbone" of the study, Golin said, was an electronic pill bottle cap called MEMS, for Medication Event Monitoring System. "MEMS records the exact time and date every time the pill bottle is opened. Each method had shortcomings, but MEMS was the most objective way to measure adherence," she said.

The researchers used the three measures to generate a Combined Adherence Score, CAS. The CAS was both more sensitive and more specific than any of the measures used alone. In other words, it was the best at spotting people who were not taking their medication, and also at distinguishing those who were from those who were not.

Because of the amount of information that needs to be collected, most health clinics probably wouldn't use the CAS, Golin said. "But for research purposes, particularly where you want to link this behavior to reductions in the amount of virus in a patient's blood, it's really critical that you measure adherence as accurately as possible. And this gives people a new way of doing that that's not been done before."
-end-
Support for this study came from the National Institute of Allergy and Infectious Diseases, National Institutes of Health.

By Steven Baragona
UNC-CH School of Medicine

media note: Contact Dr. Golin at 919-966-7939; carol_golin@unc.edu. Contact Dr. Kaplan at 919-966-2536.
School of Medicine contact: Leslie Lang, 919-843-9687; llang@med.unc.edu

University of North Carolina Health Care

Related HIV Articles from Brightsurf:

BEAT-HIV Delaney collaboratory issues recommendations measuring persistent HIV reservoirs
Spearheaded by Wistar scientists, top worldwide HIV researchers from the BEAT-HIV Martin Delaney Collaboratory to Cure HIV-1 Infection by Combination Immunotherapy (BEAT-HIV Collaboratory) compiled the first comprehensive set of recommendations on how to best measure the size of persistent HIV reservoirs during cure-directed clinical studies.

The Lancet HIV: Study suggests a second patient has been cured of HIV
A study of the second HIV patient to undergo successful stem cell transplantation from donors with a HIV-resistant gene, finds that there was no active viral infection in the patient's blood 30 months after they stopped anti-retroviral therapy, according to a case report published in The Lancet HIV journal and presented at CROI (Conference on Retroviruses and Opportunistic Infections).

Children with HIV score below HIV-negative peers in cognitive, motor function tests
Children who acquired HIV in utero or during birth or breastfeeding did not perform as well as their peers who do not have HIV on tests measuring cognitive ability, motor function and attention, according to a report published online today in Clinical Infectious Diseases.

Efforts to end the HIV epidemic must not ignore people already living with HIV
Efforts to prevent new HIV transmissions in the US must be accompanied by addressing HIV-associated comorbidities to improve the health of people already living with HIV, NIH experts assert in the third of a series of JAMA commentaries.

The Lancet HIV: Severe anti-LGBT legislations associated with lower testing and awareness of HIV in African countries
This first systematic review to investigate HIV testing, treatment and viral suppression in men who have sex with men in Africa finds that among the most recent studies (conducted after 2011) only half of men have been tested for HIV in the past 12 months.

The Lancet HIV: Tenfold increase in number of adolescents on HIV treatment in South Africa since 2010, but many still untreated
A new study of more than 700,000 one to 19-year olds being treated for HIV infection suggests a ten-fold increase in the number of adolescents aged 15 to 19 receiving HIV treatment in South Africa, according to results published in The Lancet HIV journal.

Starting HIV treatment in ERs may be key to ending HIV spread worldwide
In a follow-up study conducted in South Africa, Johns Hopkins Medicine researchers say they have evidence that hospital emergency departments (EDs) worldwide may be key strategic settings for curbing the spread of HIV infections in hard-to-reach populations if the EDs jump-start treatment and case management as well as diagnosis of the disease.

NIH HIV experts prioritize research to achieve sustained ART-free HIV remission
Achieving sustained remission of HIV without life-long antiretroviral therapy (ART) is a top HIV research priority, according to a new commentary in JAMA by experts at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

The Lancet HIV: PrEP implementation is associated with a rapid decline in new HIV infections
Study from Australia is the first to evaluate a population-level roll-out of pre-exposure prophylaxis (PrEP) in men who have sex with men.

Researchers date 'hibernating' HIV strains, advancing BC's leadership in HIV cure research
Researchers have developed a novel way for dating 'hibernating' HIV strains, in an advancement for HIV cure research.

Read More: HIV News and HIV Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.