Multiplex PCR have also been shown to provide a low-cost alternative to DNA probe
methods for rapid identification of MAC [17]. Biopsies from other normally sterile body sites can prove diagnostic. Stains of biopsy specimens from bone marrow, lymph http://www.selleckchem.com/products/icg-001.html node or liver may demonstrate acid-fast organisms or granulomata weeks before positive blood culture results are obtained [18,19]. 8.3.4.1 Treatment regimens for DMAC. • Antimycobacterial treatment of DMAC requires combination therapy that should include a macrolide and ethambutol, with or without rifabutin (category Ib recommendation). Macrolide-containing regimens are associated with superior clinical outcomes in randomized clinical trials as compared to non-macrolide-containing regimens [20] (category Ib recommendation). Clarithromycin and azithromycin have both demonstrated clinical and microbiological activity in a number of studies; however, macrolide monotherapy is associated Selleckchem Mitomycin C with rapid emergence of resistance [21]. Clarithromycin has been studied more extensively than azithromycin and is associated with more rapid clearance of MAC from the blood [22,23]. However, azithromycin has fewer drug interactions and is better tolerated
[24]. The dose of clarithromycin should not exceed 500 mg bd as higher doses have been associated with excess mortality [25]. Emergence of macrolide resistance is associated with a return of clinical symptoms and/or increased bacterial
counts in some patients [21]. Therefore, addition of at least one further class is recommended. Ethambutol is the most commonly recommended second drug [25] and GBA3 its addition to combinations used for MAC treatment reduces the development of macrolide resistance [26,27]. Ethambutol does not interact with currently available antiretroviral agents. A third drug (usually rifabutin) may be included in the regimen. One randomized clinical trial demonstrated that the addition of rifabutin to the combination of clarithromycin and ethambutol improved survival and the chance of complete microbiological response during the study period, though not microbiological clearance at the primary end-point of 12 weeks or relapse rate, while another study showed it reduced emergence of drug resistance [28,29]. Rifabutin dosage should not exceed 300 mg/day (or 450 mg if given with efavirenz or 150 mg three times a week if given with ritonavir) as cases of uveitis have been reported with higher doses, especially when given with clarithromycin [30–32]. It should be noted that many of the benefits of rifabutin were described pre-HAART and the benefits may be more marginal if HAART is administered.