Featured Research

from universities, journals, and other organizations

New way to ensure effectiveness of TB treatment?

Date:
January 3, 2012
Source:
UT Southwestern Medical Center
Summary:
A new study using a sophisticated "glass mouse" research model has found that multidrug-resistant tuberculosis is more likely caused in patients by speedy drug metabolism rather than inconsistent doses, as is widely believed.

A UT Southwestern Medical Center study using a sophisticated "glass mouse" research model has found that multidrug-resistant tuberculosis (TB) is more likely caused in patients by speedy drug metabolism rather than inconsistent doses, as is widely believed.

If the study published in The Journal of Infectious Diseases is borne out in future investigations, it may lead to better ways to treat one of the world's major infectious diseases. Health workers worldwide currently are required to witness each administration of the combination of drugs during months of therapy.

"Tuberculosis is a common ailment, accounting for up to 3 percent of all deaths in many countries. Although effective therapy exists, there are still cases of treatment failure and drug resistance remains a threat," said Dr. Tawanda Gumbo, associate professor of internal medicine and senior author of the study.

The results seem to challenge the current approach endorsed by the World Health Organization.

Under that method, directly observed therapy-short-course strategy (DOTS), TB that responds to medication is treated with a cocktail of drugs under the supervision of health care workers, who in many countries must travel to isolated villages -- a costly and time-consuming process.

"Every TB patient is supposed to be watched as they swallow their pills in order to increase adherence and decrease emergence of drug resistance. This is the most expensive part of the program, but has been felt to be cost-effective since it improves compliance," said Dr. Gumbo, administrative director of research programs for the Office of Global Health at UT Southwestern.

In this study, UT Southwestern researchers created a sophisticated system of high-tech test tubes, which they called a "glass mouse," that mimicked standard therapy being given daily for 28 to 56 days, with dosing adherence varying between 0 percent and 100 percent. The threshold for defined non-adherence (failure to take a required dose of medication) was reached at 60 percent of the time or more.

"The first main finding in our laboratory model was that in fact non-adherence did not lead to multidrug resistance or emergence of any drug resistance in repeated studies, even when therapy failed. In fact, even when we started with a bacterial population that had been spiked with drug-resistant bacteria, non-adherence still did not lead to drug resistance," he said.

In fact, using computer simulations based on 10,000 TB patients in Cape Town, South Africa, the researchers discovered that approximately 1 percent of all TB patients with perfect adherence still developed drug resistance because they cleared the drugs from their bodies more quickly.

The body sees drugs as foreign chemicals and tries to rid itself of them, Dr. Gumbo said. A population of individuals with a genetic trait that speeds the process has been found in one area of South Africa that has a high rate of multidrug-resistant TB. In that population, patients who receive standard doses of drugs end up with concentrations in their bodies that are too low to kill the TB bacillus and drug resistance develops, he said.

A Journal of Infectious Diseases editorial that accompanies the study suggests that monitoring the levels of TB drugs in a patient's blood could be as important as monitoring compliance with therapy -- in contrast to current WHO guidelines.

"These data, based on our preclinical model, show that non-adherence alone is insufficient for the emergence of multidrug-resistant TB," Dr. Gumbo said. "It might be more cost-effective to measure patients' drug concentrations during treatment and intervene with dosage increases in those who quickly clear the drugs from their systems."

The work was supported by a grant from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.


Story Source:

The above story is based on materials provided by UT Southwestern Medical Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Srivastava, J. G. Pasipanodya, C. Meek, R. Leff, T. Gumbo. Multidrug-Resistant Tuberculosis Not Due to Noncompliance but to Between-Patient Pharmacokinetic Variability. Journal of Infectious Diseases, 2011; 204 (12): 1951 DOI: 10.1093/infdis/jir658

Cite This Page:

UT Southwestern Medical Center. "New way to ensure effectiveness of TB treatment?." ScienceDaily. ScienceDaily, 3 January 2012. <www.sciencedaily.com/releases/2011/12/111228111724.htm>.
UT Southwestern Medical Center. (2012, January 3). New way to ensure effectiveness of TB treatment?. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2011/12/111228111724.htm
UT Southwestern Medical Center. "New way to ensure effectiveness of TB treatment?." ScienceDaily. www.sciencedaily.com/releases/2011/12/111228111724.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
US to Track Everyone Coming from Ebola Nations

US to Track Everyone Coming from Ebola Nations

AP (Oct. 22, 2014) Stepping up their vigilance against Ebola, federal authorities said Wednesday that everyone traveling into the US from Ebola-stricken nations will be monitored for symptoms for 21 days. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Doctors Help Paralysed Man Walk Again, Patient in Disbelief

Doctors Help Paralysed Man Walk Again, Patient in Disbelief

AFP (Oct. 22, 2014) Polish doctors describe how they helped a paralysed man walk again, with the patient in disbelief at the return of sensation to his legs. Duration: 1:04 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins