Medical uses
Its use was approved in December 2012 by the U.S. Food and Drug Administration (FDA) for use in tuberculosis (TB) treatment, as part of a Fast-Track accelerated approval, for use only in cases of multidrug-resistant tuberculosis, and the more resistant extensively drug resistant tuberculosis.As of 2013 both the World Health Organization (WHO) and US Centers for Disease Control (CDC) have recommended (provisionally) that bedaquiline be reserved for people with multidrug-resistant tuberculosis when an otherwise recommended regimen cannot be designed. Clinical trials
Bedaquiline has been studied in phase IIb studies for the treatment of multidrug-resistant tuberculosis while phase III studies are currently underway. It has been shown to improve cure rates of smear-positive multidrug-resistant tuberculosis, though with some concern for increased rates of death (further detailed in the Adverse effects section).Small studies have also examined its use as salvage therapy for non-tuberculous mycobacterial infections.It is a component of the experimental BPaMZ combination treatment (bedaquiline + pretomanid + moxifloxacin + pyrazinamide). Side effects
The most common side effects of bedaquiline in studies were nausea, joint and chest pain, and headache. The drug also has a black-box warning for increased risk of death and arrhythmias, as it may prolong the QT interval by blocking the hERG channel. Everyone on bedaquiline should have monitoring with a baseline and repeated ECGs.
Co-administration with ketoconazole, a strong CYP3A4 inhibitor, results in a 22% increase in the AUC, and potentially an increase in the rate of adverse effects experiencedSince bedaquiline can also prolong the QT interval, use of other QT prolonging drugs should be avoided. Other medications for tuberculosis that can prolong the QT interval include fluoroquinolones and clofazimine. Mechanism of action
Bedaquiline blocks the proton pump for ATP synthase of mycobacteria. It is the first member of a new class of drugs called the diarylquinolines. Bedaquiline is bactericidal. ATP production is required for cellular energy production and its loss leads inhibition of mycobacterial growth within hours of the addition of bedaquiline. The onset of bedaquiline-induced mycobacterial cell death does not occur until several days after treatment, but nonetheless kills consistently thereafter. Resistance
The specific part of ATP synthase affected by bedaquiline is subunit c which is encoded by the gene atpE. Mutations in atpE can lead to resistance. Mutations in drug efflux pumps have also been linked to resistance. Ongoing research
In vitro experiments have indicated that Bedaquiline may also target the mitochondrial ATP synthase of malignant mammalian cells and reduce the rate of metastasis. History
Bedaquiline was described for the first time in 2004 at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) meeting, after the drug had been in development for over seven years.