**Moxifloxacin**

*In-vitro m*oxifloxacin (MXF) show to kill a subpopulation of tubercle bacilli that not killed by RIF, while the older FQs, (ciprofloxacin) CPX, and (ofloxacin) OFX did not have any major bactericidal effect. The MXF obstructs protein synthesis in gradually metabolizing bacteria through a mechanism that varies from that used by RIF. In mice models, the effect of MXF against tubercle bacilli was comparable to that of INH [59]. In combination with MXF and PZA has been killing the bacilli more successfully than the INH + RIF + PZA combination [60]. The substitution of MXF with INH in the standard drug therapy could relieve a probable antagonism among the presently used drugs [61]. The MXF might be a promising candidate drug to shorten TB treatment [62, 63].

**Nitroimidazopyrans and Nitroimidaoxazoles derivatives**

*Study of Various Chemically and Structurally Diverse Currently Clinically Used…*

be used in combination therapy [74]. *Nitroimidazole PA-824*

*DOI: http://dx.doi.org/10.5772/intechopen.95538*

*Nitroimidazoles CGI 17341*

*Mtb*, including MDR strains. *Nitroimidazole OPC-67683*

**Imidazole Analogues**

progressing TB indication [76].

INH and RIF.

**39**

treated mice [2–4].

In this series, the lead molecules are CGI 17341 and PA824/PA1343 and inhibit the cell wall synthesis. However, two key areas of concern also require to attendpossible mutagenicity resulting from the presence of a nitro group, and the chance for the development of drug resistance. The latter is encouraged by the reality that the nitroimidazoles induce a high rate of mutation [2–4], leading to uncertainties that this might cause the appearance of MDR bacteria. Since the drugs will certainly

The PA-824 is a nitroimidazole derivative and used as anti-TB agent. PA-824 acts mainly as synthesis of cell wall components inhibitor. *In vitro*, PA-824 showed

resistance with currently used anti-TB drugs. Moreover, PA-824 has shown *in-vitro* bactericidal activity against both replicating and static bacteria [4]. The PA-824 bactericidal effect against nonreplicating bacteria was equivalent to the RIF. Use of PA-824 as monotherapy in mice and cause reduced bacterial counts in the lungs is better than RIF or INH monotherapy. After 12 weeks of treatment with PA-824, RIF, or INH, complete removal of the bacterial load was not getting in any of the

The CGI 17341 has substantial potential as anti-TB agent in a preclinical study. *In-vitro* at 0.04 to 0.3 μg/ml, it inhibited both drug-susceptible and MDR-TB strains and exhibited no cross-resistance with INH, RIF, SM, or EBM. *In-vitro* against *Mtb*,

ciprofloxacin, and the oxazolidinone DuP 721. In *Mtb*-infected mice, oral treatment with CGI 17341 on days 11 and 12 after infection resulted in an ED50 of 7.7 mg/kg and showed a significant dose-dependent progress in survival time [75]. These drugs were not mutagenic and showed potent activity against replicating and static

It is mycolic acid inhibitors and interferes with the biosynthesis of the mycobacterial cell wall. *In vitro*, OPC-67683 was exhibited high activity against drugsensitive as well as DR strains with MICs varying 6–24 ng/mL. There is no crossresistance with any of the current first-line anti-TB drugs. Moreover, OPC-67683 exhibited strong intracellular activity against the *Mtb*H37Rv residing within human macrophages and type II pneumocytes. The OPC-67683 is active against *Mtb*H37v and MDR-TB strains *in-vivo* starting from a concentration of 0.03125 mg/body [2– 4]. The OPC-67683 exhibited 6–7 fold elevated activity compared to first-line drugs

Miconazole is a well-known antifungal drug that has been accounted for to have anti-TB activity *in vitro* against *Mtb*H37Ra (MIC 2 μg/ml). It inhibiting replicating bacteria and also has some effect on stationary phase bacilli [88]. Unfortunately, miconazole is not active orally and therefore is little additional interest in

its action was similar to that of INH and RIF and higher to SM, norfloxacin,

high activity against drug-sensitive and MDR-TB strains, there is no cross-
