Bedaquiline for Drug-Resistant TB: 24-Week Regimen, Combination Duration, and When to Stop or Extend

　　1.Why duration cannot be self-decided

　　Bedaquiline is a diarylquinoline antimycobacterial agent and is used only as part of combination therapy,never alone.Stopping depends on the full regimen:resistance pattern,susceptibility of companion drugs,sputum-culture conversion,cavity and lesion response,treatment interruptions,and safety signals such as QT prolongation and liver tests.

　　Symptom improvement does not equal bacterial eradication or cure.

　　2.Classic 24-week framework

　　Adults commonly receive 400mg once daily for weeks 1–2,then 200mg three times weekly for weeks 3–24,with at least 48 hours between doses,total about 24 weeks.Take with food,swallow whole,do not split or crush.

　　This framework fits many classic MDR-TB plans.With newer all-oral regimens,bedaquiline duration follows the chosen combination rather than a fixed“6 months then stop”rule.

　　3.Duration in modern combination regimens

　　6-month all-oral short course:eligible patients may receive bedaquiline+pretomanid+linezolid+moxifloxacin(BPaLM);if fluoroquinolone-resistant,bedaquiline+pretomanid+linezolid(BPaL).Bedaquiline usually covers the early phase,total regimen about 6 months.

　　9-month all-oral:fluoroquinolone-sensitive patients who are not suitable for 6 months may receive bedaquiline with linezolid,a fluoroquinolone,clofazimine,pyrazinamide,and others;total about 9 months,with bedaquiline duration defined by the protocol.

　　Long/individualized courses:XDR,prior failures,few effective drugs,or complex site involvement may require 18–20 months or individualized design;extending bedaquiline beyond 24 weeks is a specialist decision.

　　4.When extension may be considered

　　Extension is not“longer is better.”It may be reviewed when:

　　sputum culture remains positive at around 3 months or radiographic response is slow;

　　companion core drugs are poorly tolerated and removing them leaves no effective regimen;

　　XDR/pre-XDR,heavily pretreated,bedaquiline still susceptible and well tolerated.

　　Extension requires regular ECG,electrolytes,liver tests,and sputum monitoring.

　　5.Safety stop rules

　　Hold or discontinue bedaquiline and review all QT-prolonging companions if:

　　clinically significant ventricular arrhythmia,or repeated QTcF>500ms;

　　transaminase elevation with hyperbilirubinemia or other preset hepatotoxicity thresholds;

　　severe drug-induced liver injury,marked uncorrected electrolyte disturbance;

　　other serious adverse events where continuing risks outweigh benefit.

　　Baseline and on-treatment ECG,potassium/magnesium/calcium,and LFTs are needed;moxifloxacin and clofazimine add QT burden.

　　6.Patient execution

　　Do not reduce,skip,or stop the overall resistant-TB regimen independently.For the first 2 weeks,a missed dose is usually not made up and the schedule continues;under the thrice-weekly phase,follow product rules to make up within the weekly total.All stops,extensions,or switches should be decided by a TB specialist using susceptibility testing and cultures.