Tuberculosis chemoprophylaxis

Despite these advances in our understanding of the risk factors that predispose to isoniazid-induced hepatotoxicity/ it remains unclear whether age/ the predominant risk factor (Table 16.3)/ exerts its effects either on isoniazid metabolism or on protective mechanisms that as yet remain undefined. Clearly/ more work is needed in this area/ especially because understanding the biochemical basis of these risk factors plays a central role in developing guidelines for using isoniazid for chemoprophylaxis of tuberculosis (35). 

Sorresso DJ, Mehta JB, Harvil LM, Bendy S. Underutilization of isoniazid chemoprophylaxis in tuberculosis contacts 50 year of age and older. A prospective analysis. Chest 1995 108 706-11. 

CHEMOPROPHYLAXIS OF TUBERCULOSIS Chemoprophylaxis of tuberculosis involves treating latent infection to prevent progression to active disease. Latent infection may be... 

Prophylactic therapy should be considered in patients exposed to tuberculosis who have evidence of infection, including immunosuppressed patients e.g., HIV-infected) with >5 mm induration on PPD testing immunocompetent patients with >10 mm induration on PPD testing and risk factors for TB but no apparent disease and those with a history of tuberculosis in whom the disease is currently inactive. The main risk of chemoprophylaxis is isoniazid-induced hepatitis. Monitored isoniazid prophylaxis minimizes this risk, even in patients over the age of 35. 

Burry JN (1974) Persistent phototoxicity due to nalidixic acid. Arch Dermatol 109 263 Byrd RB, Horn BR, Solomon DA, Griggs GA (1979) Toxic effects of isoniazid in tuberculosis chemoprophylaxis. Role of biochemical monitoring in 1,000 patients. JAMA 241 1239... 

Tuberculosis chemoprophylaxis has been retrospectively evaluated in 63 Spanish patients with latent tuberculosis out of 497 with inflammatory bowel disease who were candidates for anti-TNFa therapy [31 ]. Skin tests for tuberculosis were positive in 86% after a single exposure, but 14% needed a booster. There were no susceptibility factors for hepatotoxicity. All but one was treated with isoniazid alone for 6 or 9 months, and only one required chemoprophylaxis withdrawal because of hepatotoxicity. There were no cases of active tuberculosis in the patients who were treated with anti-TNFa therapy. The authors concluded that chemoprophylaxis is safe in patients with inflammatory bowel disease, even in those taking concomitant, potentially hepatotoxic drugs. 

In a retrospective study in Brazil in 319 patients who underwent liver transplant and survived more than 1 month tuberculosis was identified in five women, mean age 40 years [ST f. None received chemoprophylaxis before or after liver transplant. Two had disseminated tuberculosis, two had pulmonary disease, and one had extrapulmonary disease. Cultures were positive in four. Four patients received isoniazid, rifampicin, and... 

Migita K, Umeno T, Miyagawa K, Izumi Y, Sasaki E, Kakugawa T, et al. Development of interstitial pneumonia in a patient with rheumatoid arthritis induced by isoniazid for tuberculosis chemoprophylaxis. Rheumatol Int 2012 32(5) 1375-7. 

About 1.8 billion individuals, or about one-third of the world s population, are infected with Mycobacterium tuberculosis, and most of these individuals have latent infection. Although malnutrition is a major risk factor for the progression of tuberculosis, tuberculosis control programs have tended to focus upon chemoprophylaxis and chemotherapy alone, rather than upon improvement of host nutritional status. For over one hundred years, cod-liver oil, a rich source of vitamins A and D, was used as a treatment for tuberculosis. The role of nutrition and tuberculosis remains a major area of neglect, despite the promise that micronutrients have shown as therapy for other types of infections and the long record of the use of vitamins A and D for treatment of pulmonary and miliary tuberculosis in both Europe and the United States. A recent clinical trial suggests that high dose vitamin A supplementation does not alter the morbidity of tuberculosis in children [65]. Studies have not been conducted which address the use of multivitamins and minerals or vitamins A plus D as an adjunct therapy for tuberculosis. 

Infections may be caused by reactivation of a primary infection in the recipient, reactivation of a lesion from the donor lung, or as a primary infection. The (Morales et al. 2005) increase in the number of solid organ transplants has resulted in an increased incidence of opportunistic infections, including infection by typical and atypical mycobacteria, with the risk of developing tuberculosis. Pretransplant chemoprophylaxis with isoniazid has become increasingly common in an attempt to prevent the disease. The source of infection in tuberculosis (TB) may be difficult to identify. There are few reports on TB in lung transplantation (Baldi et al. 1997 Miller et al. 1995). 

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