Clarithromycin tuberculosis

M kansasii Resembles tuberculosis Ciprofloxacin, clarithromycin, ethambutol, isoniazid, rifampin, trimethoprim-sulfamethoxazole... 

Resistant organisms. Initial resistance occurs in about 4% of isolates in the UK, usually to isoniazid. Multiple-drug-resistant tuberculosis, i.e. resistant to rifampicin and isoniazid at least, should be treated with three or four drugs to which the organisms are sensitive and should extend for 12-24 months after cultures become negative. Treatment of such cases requires expert management. Atypical mycobacteria are often resistant to standard drugs their virulence is low but they can produce serious infection in immunocompromised patients which may respond, e.g. to clarithromycin or a quinolone, often in combination. 

Ototoxicity was attributed to clarithromycin in a 76-year-old man 4 days after he started to take clarithromycin for atypical pulmonary tuberculosis (17). When the clarithromycin was withdrawn his hearing improved subjectively, but it worsened again on re-exposure. 

Macrolides/Azalides. The macrohde clarithromycin and azalide azithromycin represent substantial advances in the treatment of MAC but demonstrate limited activity against M. tuberculosis and are not used frequently for... 

Unfortunately, MAC is resistant to the standard drugs used for tuberculosis, such as isoniazid and pyrazinamide. Multiple agents such as rifampin, rifabutin (ansamycin), clofazimine, imipenem, amikacin, ethambutol, ciprofloxacin, clarithromycin, and azithromycin have varying degrees of in vitro anti-MAC activity. Controversy formerly existed as to whether treatment for MAC is beneficial, but data indicate that an aggressive therapeutic approach decreases symptoms... 

MAC prophylaxis is now strongly recommended for all HIV-infected adults and adolescents with CD4 counts of fewer than 50 cells/mcL. The first-line choices are either azithromycin (1200 mg once weekly) or clarithromycin (500 mg twice daily) rifabutin is an alternative. Persons considered for prophylaxis should be evaluated to be sure that they do not have active disease owing to MAC or M. tuberculosis. 

Rifabutin is effective for the prevention of MAC infection in HIV-infected individuals. At a dose of 3(X) mg per day, rifabutin decreased the frequency of MAC bacteremia (2%). However, azithromycin or clarithromycin are more effective and less likely to interact with highly active antiretroviral therapy (HAART) drugs. Rifabutin also is commonly substituted for rifampin in the treatment of tuberculosis in HIV-infected patients, as it has a less profound CYP-dependent interaction with indinavir and nelfinavir. Rifabutin also is used in combination with clarithromycin and ethambutol for the therapy of MAC disease. 

MAC is much less susceptible than M tuberculosis to conventional antimycobacterial drugs. Both isoniazid and pyrazinamide have minimal activity against MAC. Currently, the optimum regimen consists of clarithromycin for azithromycin) with ethambutol and rifabutin. The answer is (D). 

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