Bedaquiline 20mg tablets

Bedaquiline is primarily subjected to oxidative metabolism leading to the formation of N-monodesmethyl metabolite (M2). M2 is not thought to contribute significantly to clinical efficacy given its lower average exposure (23% to 31%) in humans and lower antimycobacterial activity (4-fold to 6-fold lower) than the parent compound. However, M2 plasma concentrations appeared to correlate with QT prolongation.[L48506]

Bedaquiline inhibits mycobacterial TB at a minimal inhibitory concentration (MIC) from 0.002-0.06 μg/ml and with a MIC₅₀ of 0.03 μg/ml. The proportion of naturally resistant bacteria is low, estimated to be in one strain over 10⁷/10⁸ bacteria. Bacteria that have smaller ATP stores (such as dormant, nonreplicating bacilli) are more susceptible to bedaquiline.[A7484]

Additionally, bedaquiline is also effective against nontuberculous mycobacteria, with MICs ranging from 0.06 to 0.5 μg/ml.[A7484]

A potential for the development of resistance to bedaquiline in M. tuberculosis exists. Modification of the atpE target gene, and/or upregulation of the MmpS5-MmpL5 efflux pump (Rv0678 mutations) have been associated with increased bedaquiline MIC values in isolates of M. tuberculosis. Target-based mutations generated in preclinical studies lead to 8- to 133-fold increases in bedaquiline MIC, resulting in MICs ranging from 0.25 to 4 micrograms per mL. Efflux-based mutations have been seen in preclinical and clinical isolates. These lead to 2- to 8-fold increases in bedaquiline MICs, resulting in bedaquiline MICs ranging from 0.25 to 0.5 micrograms per mL.[L48506]