BACKGROUND & OBJECTIVE There is a need to understand the nature of drug resistance patterns and predictors of emergence of drug resistance in Mycobacterium tuberculosis. There could be common factors/mechanisms for resistance to the drugs, isoniazid and ethambutol, both acting on cell wall. The present study was conducted to analyze the antimycobacterial susceptibility patterns of M. tuberculos...

Treatment of tuberculosis: A 6-month regimen consisting of isoniazid, rifampin, and pyrazinamide given for 2 months followed by isoniazid and rifampin for 4 months is effective treatment in patients with fully susceptible organisms who comply with the treatment regimen. It may be advisable to include ethambutol in the initial phase when isoniazid resistance is suspected. A 9-month regimen consi...

CONTEXT Isoniazid preventive therapy for latent tuberculosis (TB) infection has been debated because of the risk of hepatotoxicity. The frequency of hepatotoxicity was 0.5% to 2.0% in early studies but may have changed with new criteria for diagnosis and patient selection. OBJECTIVE To determine the rate of isoniazid hepatotoxicity in patients managed according to current guidelines and pract...

BACKGROUND It is believed that the cessation of isoniazid's early bactericidal activity during the initial phase of antituberculosis therapy is due to the depletion of Mycobacterium tuberculosis in the exponential phase of growth. We examined the veracity of this cornerstone belief. METHODS We used an in vitro infection model in which M. tuberculosis was exposed to isoniazid concentration-tim...

The bactericidal activity of gatifloxacin, alone and in combination with isoniazid and rifampin, was studied on both exponential- and stationary-phase cultures of Mycobacterium tuberculosis strain H37Rv. On log-phase cultures, the bactericidal activity of gatifloxacin at 4 microg/ml was rapid and was very similar to that of isoniazid. At concentrations of 0.25 and 4 microg/ml, gatifloxacin enha...

Objective of the resent study was to determine the effect of ofloxacin (OXC) on the pharmacokinetics of isoniazid (INH). Five healthy volunteers aged 18 – 39 years participated in this study after an informed consent. The study was carried out in two phases with an interval of one-week drug wash out period in between phases. In phase one (INH alone), each subject received 300mg of isoniazid (IN...

By designing a novel electrolytic flow cell, the strong oxidant BrO2 was electrogenerated on-line in KBr solution and its concentration could be readily adjusted on-line with the flow-injection technique and an electrochemical method. The chemical reaction between BrO2 and luminol in alkaline medium is accompanied by weak emission of light due to chemiluminescence (CL). It was found that the is...

Interventional bronchology techniques have been employed as an effective first-line treatment in patients with tracheobronchial obstruction. However, recurrent stenosis produced by granulation tissue requires repeated procedures. Previous studies have indicated that isoniazid regulates collagen deposition and decreases collagen content. Thus, isoniazid has been successfully administered to pati...

Isoniazid and thioacetazone are the two important antitubercular drugs. In case of thioacetazone it is established that it inhibits mycolic acid cyclopropane synthase but the exact binding site accounting for such inhibition is presently unknown. In case of isoniazid its action on the said enzyme is unexplored. In this work we have analyzed the binding of isoniazid and thioacetazone with mycoli...

One of the proposed mechanisms for the action of iwonicotinic acid hydrazide (isoniazid) has been the inhibition of enzyme systems which require pyridoxal phosphate (Cymerman-Craig, Rubbo, Willis & Edgar, 1955). However, it appeared unlikely that the inhibition of an enzyme system present in many bacteria could account for the highly specific activity of isoniazid in low concentrations against ...