TY - JOUR
T1 - Promising antituberculosis activity of the oxazolidinone PNU-100480 relative to that of linezolid in a murine model
AU - Williams, K. N.
AU - Stover, C. K.
AU - Zhu, T.
AU - Tasneen, R.
AU - Tyagi, S.
AU - Grosset, J. H.
AU - Nuermberger, E.
PY - 2009/4
Y1 - 2009/4
N2 - Oxazolidinone antibiotics have activity against Mycobacterium tuberculosis. Linezolid, the only marketed oxazolidinone, has been used off-label in combination regimens to treat multidrug-resistant tuberculosis, but its precise contribution to the efficacy of such combinations is unclear. Another oxazolidinone, PNU-100480, has been demonstrated to have more potent activity in vitro and in a murine model of tuberculosis. In this study, we compared the pharmacokinetics and the antituberculosis activities of these two oxazolidinones over a range of doses and found that linezolid has limited activity at clinically relevant doses in the murine model compared to that of PNU-100480, which has potent bactericidal activity, even at lower drug exposures. These findings were unexpected, given the similar in vitro activities of PNU-100480, its major metabolites, and linezolid. Moreover, the incorporation of PNU-100480 dramatically improved the bactericidal activities of regimens containing current first-line antituberculosis drugs and moxifloxacin. For example, the addition of PNU-100480 (100 mg/kg of body weight/day) to the standard daily regimen of rifampin (rifampicin), isoniazid, and pyrazinamide resulted in an additional 2.0-log10-unit reduction in lung CFU counts during the first 2 months of treatment. The combination of PNU-100480, moxifloxacin, and pyrazinamide, which does not contain either rifampin or isoniazid, was also more active than rifampin, isoniazid, and pyrazinamide. These results suggest that PNU-100480 may have the potential to significantly shorten the duration of therapy for drug-susceptible as well as multidrug-resistant tuberculosis.
AB - Oxazolidinone antibiotics have activity against Mycobacterium tuberculosis. Linezolid, the only marketed oxazolidinone, has been used off-label in combination regimens to treat multidrug-resistant tuberculosis, but its precise contribution to the efficacy of such combinations is unclear. Another oxazolidinone, PNU-100480, has been demonstrated to have more potent activity in vitro and in a murine model of tuberculosis. In this study, we compared the pharmacokinetics and the antituberculosis activities of these two oxazolidinones over a range of doses and found that linezolid has limited activity at clinically relevant doses in the murine model compared to that of PNU-100480, which has potent bactericidal activity, even at lower drug exposures. These findings were unexpected, given the similar in vitro activities of PNU-100480, its major metabolites, and linezolid. Moreover, the incorporation of PNU-100480 dramatically improved the bactericidal activities of regimens containing current first-line antituberculosis drugs and moxifloxacin. For example, the addition of PNU-100480 (100 mg/kg of body weight/day) to the standard daily regimen of rifampin (rifampicin), isoniazid, and pyrazinamide resulted in an additional 2.0-log10-unit reduction in lung CFU counts during the first 2 months of treatment. The combination of PNU-100480, moxifloxacin, and pyrazinamide, which does not contain either rifampin or isoniazid, was also more active than rifampin, isoniazid, and pyrazinamide. These results suggest that PNU-100480 may have the potential to significantly shorten the duration of therapy for drug-susceptible as well as multidrug-resistant tuberculosis.
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U2 - 10.1128/AAC.01182-08
DO - 10.1128/AAC.01182-08
M3 - Article
C2 - 19075058
AN - SCOPUS:65649089528
SN - 0066-4804
VL - 53
SP - 1314
EP - 1319
JO - Antimicrobial agents and chemotherapy
JF - Antimicrobial agents and chemotherapy
IS - 4
ER -