Daily antibiotics may prevent drug-resistant TB

Prescribing antibiotic doses once or twice a week for tuberculosis (TB) treatment are more likely to lead to drug resistant strains than daily antibiotic regimens, new research has found.

The finding could lead to better treatment of the roughly 10 million people worldwide who fall ill with tuberculosis each year, the researchers said.

"We wanted to address open questions regarding treatment for tuberculosis," said study first author Elsje Pienaar from University of Michigan in the US.

"First, can we use the antibiotics that we have in a better way? And if we can change the ones that we have in some way, what modifications would be best?," Pienaar said.

The study looked into how treatments with the standard antibiotics isoniazid and rifampin fare when taken according to different regimens approved by the US Center for Disease Control.

These include larger doses a few times per week and smaller daily doses.

The computer simulations used in the study showed that daily treatment with both antibiotics is the best way to go, but even then, the drugs have a hard time killing off all of the TB bacteria.

Part of the problem is that bacteria can hide out in tumour-like lesions called granulomas.

Looking for a way to kill these holdouts, the team investigated whether increasing the number of doses would help raise the antibiotic concentrations inside the granulomas.

They found that upping the doses to nine per week, they were able to cut the time until the bacteria were wiped out by about 10 days, on average.

The computer model is based on data from experiments with rabbits and macaque monkeys.

The study was published in the journal BMC Systems Biology.