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Reverse transcriptase rifamycins

Drugs that might affect amprenavir include abacavir, aldesleukin, antacids, anticonvulsants, azole antifungals, clarithromycin, cyclosporine, dexamethasone, buffered didanosine, disulfiram, ethanol, indinavir, methadone, metronidazole, nelfinavir, nonnucleoside reverse transcriptase inhibitors, oral contraceptives, rifamycins, ritonavir, saquinavir, St. John s wort, tacrolimus, and zidovudine. [Pg.1826]

Rifabutin is derived from rifamycin and is related to rifampin. It has significant activity against M tuberculosis, M avium-intracellulare, and M fortuitum (see below). Its activity is similar to that of rifampin, and cross-resistance with rifampin is virtually complete. Some rifampin-resistant strains may appear susceptible to rifabutin in vitro, but a clinical response is unlikely because the molecular basis of resistance, rpoB mutation, is the same. Rifabutin is both substrate and inducer of cytochrome P450 enzymes. Because it is a less potent inducer, rifabutin is indicated in place of rifampin for treatment of tuberculosis in HIV-infected patients who are receiving concurrent antiretroviral therapy with a protease inhibitor or nonnucleoside reverse transcriptase inhibitor (eg, efavirenz)—drugs that also are cytochrome P450 substrates. [Pg.1050]

As has already been mentioned, some lipophilic rifamycins and some strepto-varicins and geldanamycins affect the growth of cells transformed by RNA tumour viruses or the RNA-dependent DNA polymerase (reverse transcriptase) characteristic of these viruses. Again, high drug concentrations are needed to produce an effect and only partial, but never absolute, selectivity of enzyme inhibition has been found. [Pg.36]

Nonnucleoside reverse transcriptase inhibitors Delavirdine should not be used with any rifamycin. Doses of nevirapine... [Pg.2029]

The mechanism of action of rifamycins involves primarily a strong, but noncovalent, interaction with DNA-dependent RNA polymerase enzyme in sensitive bacterial cells. The mammalian enzyme is not affected, which explains the selective toxicity neither is it mutated to resistant organisms. RNA polymerase has two components. The core enzyme contains polypeptide subunits a, J3, and i and a c factor, which are needed for recognition of RNA synthesis initiation sites. The drug binds to the J subunit of the complete enzyme only. The result is effective inhibition of RNA synthesis. It is of interest that many rifampinlike hydrazine derivatives were also found to be potent inhibitors of reverse transcriptase and shown to have antiviral properties. [Pg.259]

Certain rifamycin derivations can inhibit reverse transcriptase. [Pg.320]

Drug interactions are a special concern in patients receiving highly active antiretroviral therapy (H AART). The rifamycins accelerate the metabohsm of protease inhibitors and nonnucleoside reverse transcriptase inhibitors. Rifabutin has the least effect on serum levels and is indicated in this setting. [Pg.791]

Maytansine s ansa macrolide structure shows noteworthy similarities to those of the rifamycins [255], streptovaricins [256], tolypomycins [257], and geldanamycin [258]. The ansamycin antibiotics and their derivatives have aroused considerable interest as antiviral and antimicrobial agents, and as inhibitors of RNA tumor virus reverse transcriptases. [Pg.720]

Centers for Disease Control and Prevention. Updated guidelines for the use of rifamycins fcr tile treatment of tuberculosis among HIV-infected patients taking protease inhibitors or nonnucleoside reverse transcriptase inhibitors. MMWR (2004) 53,37. [Pg.790]

Rifamycin Antibiotics - Derived from the fermentation of Streptomyces mediterranei, this family of ansa-macrollde drugs possesses a very broad spectrum of antimicrobial activity against gram-positive and gram-negatire bacteria, mycobacteria, chlamydia, and several viruses. The activity of rifampin, the only clinical candidate of this group, has recently been reviewed by Lester.35 its efficacy is presumably due to the inhibition of bacterial derived DNA-dependent RNA polymerase and the inhibition of viral RNA-dependent DNA polymerase (reverse transcriptase). [Pg.129]

Rifampin (4,2ob)y discussed in Section 4.0, inhibits replication of vaccinia virus in mouse cells (Heller et a/., 1969). Also rifamycin SV (4.20a) inhibits reverse transcriptase, the RNA-dependent synthesizer of DNA in viruses. Unfortunately, no clinical applications of these discoveries have been made. Apart from these and the phleomycins (Section 4.0, p. 115), antiviral action has rarely been found among antibiotics. [Pg.203]

Two recent reviews of derivatives of rifamycin employed as inhibitors of reverse transcriptase have shown structures of 24-dialkylamino substituted rifamycins. However, no references were given to their preparation and it seems possible they may have been 25-dialkylamino-substituted hydroquinones, instead (40,163). [Pg.264]

The second major activity investigated for the ansamycins - reverse transcriptase inhibition - does not follow closely that of bacterial inhibition. Thus, the most active antibacterial rifamycin derivatives are rather... [Pg.280]

Thompson, F. M., L. J. Libertini, U. R. Joss, and M. Calvin Detergent Effects on a Reverse Transcriptase Activity and on Inhibition by Rifamycin Derivatives. Science 178, 505 (1972). [Pg.306]

Ting, R. C., S. S. Yang, and R. C. Gallo Reverse Transcriptase, RNA Tumour Virus Transformation and Derivatives of Rifamycin SV. Nature (London) New Biol. 236, 163(1972). [Pg.306]

Yang, S. S., F. M. Herrera, R. G. Smith, M. S. Reitz, G. Lancini, R. Ting, and R. C. Gallo Rifamycin Antibiotics Inhibitors of Rauscher Murine Leukemia Virus Reverse Transcriptase and of Purified DNA Polymerases from Human Normal and Leukemic Lymphoblasts. J. Nat. Cancer Inst. 49, 7 (1972). [Pg.308]


See other pages where Reverse transcriptase rifamycins is mentioned: [Pg.1115]    [Pg.39]    [Pg.887]    [Pg.108]    [Pg.1099]    [Pg.42]    [Pg.236]    [Pg.1580]    [Pg.1936]    [Pg.214]    [Pg.129]    [Pg.253]    [Pg.499]    [Pg.828]    [Pg.545]    [Pg.130]    [Pg.130]    [Pg.232]    [Pg.263]    [Pg.268]   
See also in sourсe #XX -- [ Pg.231 , Pg.233 ]

See also in sourсe #XX -- [ Pg.231 , Pg.233 ]




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