Early Bactericidal Activity of Linezolid, Gatifloxacin, Levofloxacin, Isoniazid (INH) and Moxifloxacin in HIV Negative Adults With Initial Episodes of Sputum Smear-Positive Pulmonary Tuberculosis

Inclusion Criteria

-Adults, male or female, age 18 to 65 years. -Women with child-bearing potential (not surgically sterilized or postmenopausal for less than 1 year) must be using or agree to use an adequate method of birth control [condom; intravaginal spermicide (foams, jellies, sponge) and diaphragm; cervical cap or intrauterine device] during study drug treatment. -Newly diagnosed sputum smear-positive pulmonary tuberculosis as confirmed by sputum acid fast bacilli (AFB) smear and chest X-ray findings consistent with pulmonary tuberculosis. -Willing and able to provide informed consent. -Reasonably normal hemoglobin (greater than or equal to 8 gm/dL), renal function (serum creatinine less than 2 mg/dL), hepatic function [serum aspartate aminotransferase (AST) less than 1.5 times the upper limit of normal for the testing laboratory and total bilirubin less than 1.3 mg/dL], and random blood glucose less than 150 mg/dL.

Exclusion Criteria

-Human immunodeficiency virus (HIV) infection. -Weight less than 75 percent of ideal body weight. -Presence of significant hemoptysis. Patients who cough up frank blood (more than blood streaked sputum) will not be eligible for enrollment. -Pregnant or breastfeeding women and those who are not practicing birth control. -Significant respiratory impairment (respiratory rate greater than 35/minute). -Clinical suspicion of disseminated tuberculosis or tuberculosis meningitis. -Presence of serious underlying medical illness, such as liver failure, renal failure, diabetes mellitus, chronic alcoholism, decompensated heart failure, hematologic malignancy or patients receiving myelosuppressive chemotherapy. -Patients receiving any of the following medications - monoamine oxidase inhibitors (phenelzine, tranylcypromine), adrenergic/serotonergic agonists such as pseudoephedrine and phenylpropanolamine (frequently found in cold and cough remedies), tricyclic antidepressants (amitriptyline, nortriptyline, protriptyline, doxepin, amoxapine, etc), antipsychotics such as chlorpromazine and buspirone, serotonin re-uptake inhibitors (fluoxetine, paroxetine, sertraline, etc.), buproprion, agents known to prolong the QTc interval [erythromycin, clarithromycin, astemizole, type Ia (quinidine, procainamide, disopyramide) and III (amiodarone, sotalol) anti-arrhythmics, carbamazepine, insulin, sulfonylureas, and meperidine. -Presence of QTc prolongation (greater than 450 msec) on baseline electrocardiogram (EKG). -Allergy or contraindication to use of study drugs. -Treatment with antituberculosis medications or other antibiotics with known activity against M. tuberculosis during the preceding 6 months. -Inability to provide informed consent. -Total white blood cell count less than 3000/mm^3. -Platelet count less than 150,000/mm^3. -Patients with suspected drug resistant tuberculosis (e.g., contact to source patient with drug resistant tuberculosis, patients who have relapsed after previous treatment for tuberculosis). -Patients likely, in the opinion of the local investigator, to be unable to comply with the requirements of the study protocol.