In vitro and ex vivo antimycobacterial potential of azole drugs against Mycobacterium tuberculosis H37Rv

The antimycobacterial activity of two clinically approved antifungal azole drugs, clotrimazole and econazole, was evaluated against Mycobacterium tuberculosis H₃₇Rv under in vitro and ex vivo conditions. The minimum inhibitory concentration (MIC₉₀) was 0.120 μg ml⁻¹, whereas the minimum bactericidal concentration and effective concentration was 0.125 μg ml⁻¹ for both the drugs demonstrating their potent antimycobacterial activity. Further, the azole drugs exhibited a synergistic activity with either rifampicin or isoniazid as evaluated on the basis of reduction of colony forming units. The results suggest that azole compounds bear the potential to enhance the efficacy of currently prescribed antitubercular drugs.