Rifabutin is well-tolerated in people with HIV-related TB, but new findings suggest that those with low CD4+ cell counts have a higher risk of treatment failure or relapse due to acquired rifamycin resistance. Since patients co-infected with TB and HIV are likely to be treated for TB first, when the CD4+ cell population is depressed at the time TB treatment begins, doctors and patients should be aware of the possibility for rifamycin resistance to develop.Rifamycins, including rifabutin, are useful in the treatment of Chlamydophila pneumoniae (Cpn) infection. Rifabutin is being tested in clinical trials for treating Crohns disease as part of the anti-MAP therapy. In a Phase III study administering sub-therapeutic doses of rifabutin in combination therapy to patients not identified with MAP infections, it was associated with significant short term benefits.Rifabutin is also being investigated for the treatment of infections caused by the Gram-negative bacillus Acinetobacter baumannii, which has shown promise in animal studies. History
Scientists at the Italian drug company Achifar discovered rifabutin in 1975. (Eventually Archifar became part of Farmitalia Carlo Erba, a unit of the conglomerate Montedison which was subsequently bought by Pharmacia) This companys Adria Laboratories subsidiary filed for Food and Drug Administration (FDA) approval of rifabutin under the brand name Mycobutin in the early 1990s and the drug gained FDA approval in December 1992.Rifabutin is primarily bactericidal antibiotic drug used to treat tuberculosis. Its effect on bacteria is based on the DNA-dependent RNA polymerase blocking drug rifamycin S, a semi-synthetic derivative.
It is effective, for example, in highly resistant mycobacteria, Gram-positive bacteria (and some are effective against Gram-negative bacteria), but also against Mycobacterium tuberculosis, M. leprae, and M. avium intracellulare. References
External links
"Rifabutin". Drug Information Portal. U.S. National Library of Medicine.