**3.7 Thioridazine (phenothiazine)**

Thioridazine was a drug used in the treatment of anxiety disorders and schizophrenia. Manufactured by Novartis, it was removed from the market in 2005 due to associated cardiac arrhythmias and other adverse effects. The removal of this drug had a devastating effect on patients being treated for schizophrenia, and a study in Finland indicated a doubling of hospital admitted relapsed patients after the withdrawal of the drug [32]. Thioridazine was coincidentally the only drug that appeared in the network analysis on the topic of repurposing drugs for TB (**Figures 2** and **3**). It has shown *in vitro* bactericidal activity against susceptible and resistant strains of *M. tuberculosis* as well as intracellular activity on human macrophages with limited cellular toxicity [33, 34]. A retrospective study on a trial conducted in Argentina on 17 XDR-TB patients revealed the potential use of this drug in a last-resort treatment. Thioridazine was combined with linezolid and moxifloxacin. Although clinically relevant adverse effects (neurotoxicity and haematological disorders) were observed, and two patients had to have the treatment halted, the combination was able to achieve negative cultures in 15 patients and status of "cured" in 11 patients. The authors have recommended the use of this combination for compassionate use [35].
