Effect of antituberculosis treatment on human liver

Antituberculosis treatment is the common cause of drug induced liver injuries or hepatotoxicity in the patients. It has been proved in many studies that the effect occure due the elevated level of the liver enzymes like ALT, AST, ALP.The study was carried on the patients of DOTs centre at Shree Ramjivan Choudhary Medical Hospital and Research Centers and all the estimation were done in Sarasvati Pathology laboratory, Mahal, Nagpur. During three months observation the elevated level of the liver enzymes like ALP and SGPT has been detected in most o the patients. Out of 20 patients, who include 14 males and 6 females, the elevated level of SGPT was found in two males. One male showed the levels of both the enzymes and reported to have drug induced hepatitis. In females no such effects was found on the liver as the level of the enzymes were found raised but the levels were within the normal range. Thus, it can be concluded that the antituberculosis treatment impose hazardous on the patients liver leading to hepatotoxicity or drug induced liver injuries, most commonly drug induced hepatitis. Results obtained vary for person to person depending upon the immune response mounted by the individual. INTRODUCTION:Tuberculosis is a disease caused by Mycobacterium tuberculosis mostly in lungs. M. tuberculosis is pathogenic bacteria; it was first isolated by Robert Koch in 1882. The organisms shows mycolic acid on its cell surface, hence does not stain with normal bacteriological stain but is able to stain with acid fast stain and therefore classified as acid fast Gram positive bacteria [1]. In lungs it is taken up by Alveolar macrophages but these macrophages fails to digest the bacteria as the cell wall prevents the phagosomes to fuse with lysosomes. This is known as Pulmonary Tuberculosis [2]. Apart from lungs the bacteria may enter the blood stream and cause the infection in other organ such as kidney, brain, spine and other vital organ, this is known as extrapulmonary tuberculosis. It includes TB meningitis, TB of bones, TB of lymph glands and TB of abdomen, etc [3]. The infection is spread through air, droplets due to forceful activities like coughing, sneezing, etc. the person at high risk of exposure are HIV infected patients, coworker in industries especially working in mines, construction works, crushing and hospital staffs of DOT centers, etc [2]. For treatment of tuberculosis U. S. Food and Drug Administration [FDA] approved 10 drugs [4]. Out of these four drugs are most commonly used . They are –  Isoniazid (INH).  Rifampicin. (Rifampin)  Ethambutol (EMB)  Pyrazinamide(PZA) Preeti Dharmik et al. / International Journal of Pharma Sciences and Research (IJPSR) ISSN : 0975-9492 Vol 4 No 2 Feb 2013 5 Starting with the treatment of tuberculosis initially four drugs are prescribed which are called as the extensive period or initial phase which continues for two months following the continuation period in which drugs are reduced to two which continues for 4-8 months depending upon condition of patients. [4] These antituberculosis treatments though very effective have many side effects on patient’s liver. As compared to another treatments such antimicrobial and anticonvulsants etc antituberculosis treatment is found to be main cause of drug induced hepatitis or hepatotoxicity. [5] The drugs and its side effects are: 1. Isoniazide [INH]:This drug is effective bactericidal against some strain of Mycobacterium species like M. bovis , M. tuberculosis, M. kanaess. Isoniazid first undergoes acetylation and get converted into acetyl isoniazide which further hydrolysed into two products acetyl hydrazine and isoniotinic acid. Some part is converted into hydrazine. This causes the hepatotoxicity of liver [6] and Asparate transaminase level get elevated at first few months.