 The emergence and spread of multi-drug resistant and extensively-drug resistant strains of Mycobacterium tuberculosis MDRXDR-TB have posed a great threat to global TB control and elimination, limiting treatment success rate at worrisome 50 for MDR-TB. Among various factors contributing to the development of drug resistance, low drug exposure is well recognized. To overcome this, either new drugs have to be developed or the dose of currently used therapy be optimized, or both. Fluoroquinolones levofloxacin and moxifloxacin and aminoglycosides are important drugs in the MDR-TB treatment regimen. Development of acquired drug resistance to these drugs could complicate and narrow down the available options, and further exacerbate to pre-XDR and XDR-TB. 