New York, May 19 (IANS): Instead of just one drug, prescribing patients drug combinations that reach similar parts of the body could be an effective way of combating pathogens such as viruses or bacteria, says a new study.

Prescribing patients two or more drugs that do not reach the same parts of the body could accelerate a pathogen's resistance to all of the drugs being used in treatment, the findings showed.

Not all drugs can reach all parts of the body, a situation known as "imperfect drug penetration."

In this study, researchers found that when there is a "pocket" of the body where only one drug is present, such as the brain or the digestive system, a pathogen can quickly develop resistance to one drug at a time.

"If there is a space where there is only one drug, that is the place where the pathogen can start its escape," said co-author of the study Pleuni Pennings, assistant professor of biology at San Francisco State University.

"Once it no longer has the first drug to deal with, it is very easy for it to quickly become resistant to a second drug," Pennings said.

The study could have major implications for how treatment plans are designed and prescribed to patients of HIV, malaria, tuberculosis and other ailments.

Because pathogens can quickly develop resistance to a single drug, providers often prescribe multiple drugs to increase their effectiveness.

The results of the study suggest that, when doing so, doctors should carefully consider which parts of the body each drug will reach.

For the study, the researchers ran computer simulations to look at the behaviour of pathogens in response to changes in the drugs used in treatment and their levels of penetration.

The study was published in the journal Proceedings of the National Academy of Sciences.