Follow-up to management strategies for candidates for protease inhibitors and requiring treatment for Mycobacterium tuberculosis.

42280. Source: A Tseng, Pharm D, Immunodeficiency Clinic, The Toronto Hospital, Department of Pharmacy, University of Toronto; S Walmsley, MD, Immunodeficiency Clinic, The Toronto Hospital, Department of Medicine, University of Toronto, Toronto ON. MORE ON MANAGEMENT STRATEGIES FOR CANDIDATES FOR PROTEASE INHIBITORS AND REQUIRING TREATMENT FOR MYCOBACTERIUM TUBERCULOSIS In the preceding article, Drs. Tseng and Walmsley have nicely expanded on the potential interactions of several antiretrovial agents with rifabutin and rifampin. As they pointed out, delavirdine has a clearly established interaction with rifabutin and rifampin. The clinical significance of the pharmacokinetic interactions between nevirapine or efavirenz with rifabutin and rifampin are less clear. A new option not covered in the original article or in the follow-up by Tseng and Walmsley was recently discussed during the recent World AIDS Conference in Geneva. This involves a potent new nucleoside analogue, abacavir, also known as 1592 or Ziagen™. Preliminary data suggest that the antiviral effect which can be achieved with triple nucleoside combination including AZT, 3TC/ZDV, and abacavir is of similar magnitude to that described for triple drug combination regimens using two nucleosides plus a potent protease inhibitor or two nucleosides plus a non-nucleoside reverse transcriptase inhibitor in antiretroviral therapy naïve patients. If and when these results are confirmed, this approach may offer a valid treatment option which will be unlikely to create problems when used concomitantly with rifampin or rifabutin.