minocycline and Tuberculosis--Multidrug-Resistant

Treatment of multidrug-resistant (MDR) tuberculosis (TB) is challenging because of the high toxicity of second-line drugs and the longer treatment duration than for drug-susceptible TB patients. In order to speed up novel treatment for MDR-TB, we suggest considering expanding the indications of already available drugs. Six drugs with antimicrobial activity (phenothiazine, metronidazole, doxycycline, disulfiram, tigecycline and co-trimoxazole) are not listed in the World Health Organization guidelines on MDR-TB treatment but could be potential candidates for evaluation against Mycobacterium tuberculosis. A systematic review was conducted to evaluate antituberculous activity of these drugs against M. tuberculosis. We searched PubMed, Google Scholar and Embase for English articles published up to December 31, 2012. We reviewed in vitro, in vivo and clinical antituberculous activity of these drugs in addition to pharmacokinetics and side-effects. Of the drugs effective against actively replicating M. tuberculosis, co-trimoxazole seems to be the most promising, because of its consistent pharmacokinetic profile, easy penetration into tissue and safety profile. For the dormant state of TB, thioridazine may play a potential role as an adjuvant for treatment of MDR-TB. A strategy consisting of pharmacokinetic/pharmacodynamic studies, dose finding and phase III studies is needed to explore the role of these drugs in MDR-TB treatment.

Topics: Anti-Infective Agents; Antitubercular Agents; Chemistry, Pharmaceutical; Clinical Trials as Topic; Disulfiram; Doxycycline; Drug Design; Humans; Metronidazole; Minocycline; Mycobacterium tuberculosis; Phenothiazines; Tigecycline; Trimethoprim, Sulfamethoxazole Drug Combination; Tuberculosis, Multidrug-Resistant

Drug-resistant tuberculosis represents a global emergency, requiring new drugs. We found that minocycline was highly potent in laboratory strains of Mycobacterium tuberculosis and that 30 drug-susceptible and multidrug/extensively drug-resistant clinical strains were susceptible to clinically achievable concentrations. In the hollow fiber system model, lung concentration-time profiles of 7 mg/kg/day human-equivalent minocycline dose achieved bacterial kill rates equivalent to those of first-line antituberculosis agents. Minocycline killed extracellular bacilli directly. Minocycline also killed intracellular bacilli indirectly, via concentration-dependent granzyme A-driven apoptosis. Moreover, minocycline demonstrated dose-dependent antiinflammatory activity and downregulation of extracellular matrix-based remodeling pathways and, thus, could protect patients from tuberculosis immunopathology. In RNA sequencing of repetitive samples from the hollow fiber system and in independent protein abundance experiments, minocycline demonstrated dose-dependent inhibition of sonic hedgehog-patched-gli signaling. These findings have implications for improved lung remodeling and for dual immunomodulation and direct microbial kill-based treatment shortening regimens for drug-susceptible and drug-resistant latent and active M. tuberculosis infection.

Topics: Anti-Inflammatory Agents; Antitubercular Agents; Apoptosis; Granzymes; Hedgehog Proteins; Humans; Microbial Sensitivity Tests; Minocycline; Mycobacterium tuberculosis; Signal Transduction; THP-1 Cells; Tuberculosis; Tuberculosis, Multidrug-Resistant

In the Horn of Africa, there is a high prevalence of tuberculosis that is reported to be partly driven by multidrug-resistant (MDR) Mycobacterium tuberculosis strictu sensu strains. We conducted a prospective study to investigate M. tuberculosis complex species causing tuberculosis in Djibouti, and their in vitro susceptibility to standard anti-tuberculous antibiotics in addition to clofazimine, minocycline, chloramphenicol and sulfadiazine. Among the 118 mycobacteria isolates from 118 successive patients with suspected pulmonary tuberculosis, 111 strains of M. tuberculosis, five Mycobacterium canettii, one 'Mycobacterium simulans' and one Mycobacterium kansasii were identified. Drug-susceptibility tests performed on the first 78 isolates yielded nine MDR M. tuberculosis isolates. All isolates were fully susceptible to clofazimine, minocycline and chloramphenicol, and 75 of 78 isolates were susceptible to sulfadiazine. In the Horn of Africa, patients with confirmed pulmonary tuberculosis caused by an in vitro susceptible strain may benefit from anti-leprosy drugs, sulfamides and phenicol antibiotics.

Topics: Adult; Antitubercular Agents; Chloramphenicol; Clofazimine; Djibouti; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Minocycline; Mycobacterium kansasii; Mycobacterium tuberculosis; Prospective Studies; Sulfadiazine; Tuberculosis, Multidrug-Resistant; Tuberculosis, Pulmonary