Morphine, one of the most commonly abused narcotic drugs, could provide protection against the tuberculosis causing bug Mycobacterium tuberculosis, the first ever study1 testing the known pain-reliever for a completely different application, has found.
A team of researchers from Mohali-based National Institute of Pharmaceutical Education and Research in Punjab has reported that infected mice treated with low doses of morphine showed clear protection from the bug. The team found that morphine exerted maximum effect at a dose of 5 mg per kg body weight of the mice.
"Low doses of morphine can modulate the immune system in such a way that bacterial load in target organs is lowered. Also, the preferential elimination of bacteria in the lungs of infected mice, as found in our experiments, is of direct clinical relevance," says Sarbjit Singh Jhamb, one of the researchers.
In vitro, M. tuberculosis -infected macrophages (the very cells involved in protection from infection), on treatment with low concentration of morphine inhibited the intracellular growth of the bug.
The finding could help go around the nagging problem of multi-drug resistance in TB, which kills close to three million people annually. The team feels that newer opioid compounds could be used alone or in combination with existing antitubercular drugs to treat TB.