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Updated: May 23, 2026

A High-throughput Compatible Assay to Evaluate Drug Efficacy against Macrophage Passaged Mycobacterium tuberculosis
Published on: March 24, 2017
Why thioridazine in combination with antibiotics cures extensively drug-resistant Mycobacterium tuberculosis
Leonard Amaral1, Miguel Viveiros
1Institute of Hygiene and Tropical Medicine, Universidade Nova de Lisboa, Rua Junqueira 100, 1049-008 Lisbon, Portugal. lamaral@ihmt.unl.pt
Abstract:
Thioridazine (TDZ) in combination with antibiotics to which extensively drug-resistant Mycobacterium tuberculosis (XDR-TB) is initially resistant yields a cure. This is due to the fact that TDZ enhances the killing of intracellular M. tuberculosis by non-killing macrophages, inhibits the genetic expression of efflux pumps of M. tuberculosis that extrude antibiotics prior to reaching their intended targets, and inhibits the activity of existing efflux pumps that contribute to the multidrug-resistant phenotype of M. tuberculosis. The combination of these effects of TDZ probably contributes to the successful recent cures of XDR-TB cases when the phenothiazine TDZ is used in combination with antibiotics to which the patient with XDR-TB was initially unresponsive.
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