Old antibiotics for emerging multidrug-resistant/extensively drug-resistant tuberculosis (MDR/XDR-TB)

•Drug-resistant TB is a serious obstacle to progress in global TB control.•Multidrug-resistant (MDR), extensively drug-resistant (XDR) and even totally drug-resistant (TDR) TB have been reported.•Drug adverse events, intravenous delivery, cost and availability of some antibiotics are additional problems.•MDR/XDR-TB treatment must be efficient, with few adverse events, and inexpensive, easily available, affordable oral drugs.•These conditions can only be met by old compounds (e.g. clofazimine, sulfonamides and minocycline).

Recently, multidrug-resistant tuberculosis (MDR-TB) has become a therapeutic challenge. In addition to drug resistance, drug adverse events, intravenous delivery, cost and availability of some antibiotics in low-income countries have led to a look back to old drugs, especially those efficient against closely related organisms such as Mycobacterium leprae. Here we review the available drugs that respect the conditions above and could be upgraded to first-line therapy for treating MDR-TB and extensively drug-resistant tuberculosis (XDR-TB).