Doxycycline Highly Effective Against Tuberculosis, According To New Study

Doxycycline Highly Effective Against Tuberculosis, According To New Study

According to a new finding, a new oral antibiotic is very efficient as a treatment option for tuberculosis.

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. It affects particularly the lungs, but it can affect other parts of the body, such as lymph nodes, kidneys and bones. The main symptoms are weight loss, chronic cough, blood tinged sputum, night sweats. It is considered that one-third of the world population has been infected with M. tuberculosis at some point.

Although it has been introduced in 1967, up until now, doxycycline has not been acknowledged as being efficient against tuberculosis. According to a new study, published in the American Journal of Respiratory and Critical Care Medicine, doxycycline not only fights against bacterial  growth, but also stops the progression of the disease.

Doxycycline is a semisinthetic tetracycline that kills the bacteria at certain doses or stops growth at lower doses . It is currently used to treat a variety conditions such as sinusitis, syphilis, prostatitis, pelvic inflammatory disease or acne. It is efficient not only as an antibacterial drug, but also as an antiprotozoal (can be used for prophylaxis, against malaria), and as anthelmintic (against parasites such as Wuchereria bancrofti).

Researchers at Imperial College London found that doxycycline stops the secretion of MMP-1, an enzyme that destroys lung tissue. Another interesting discovery was that doxycycline is also effective against the growth of Mycobacterium tuberculosis in guinea pigs. This finding is really astonishing considering that this particular antibiotic has been used in medical practice for over 40 years but has never been included in the tuberculosis treatment scheme.

Tuberculosis

The effect of MMP-1 on HIV-infected TB patients in South Africa was also studied. In HIV-infected TB patients, the levels of MMP-1 were low,  which explains why these patients do not suffer from such extensive lung destruction.

Currently TB is treated with isoniazid ,rifampicin and pyrazinamide for two months, followed by isoniazid and rifampicin for four months. These drugs are considered first line anti-tuberculous drugs. Second line anti-tuberculosis drugs are amynoglicosides, polypeptides, fluoroquinolones, thioamides. Tuberculosis has been treated with this combination therapy for over 30 years. This is why drug-resistant strains have emerged. Dr. Paul Elkington, from the Department of Medicine at Imperial College London, who led the study, points out the necessity of a new effective drug that could fight TB. He also underlined the idea that doxycycline is a cheap, safe and widely available antibiotic that could be used as an alternative for treating TB.

Even though the study results are very promising, a clinical trial still needs to be conducted on patients for more detailed results.