A Pilot Study of Methodology to Rapidly Evaluate Drugs for Bactericidal Activity, Tolerance, and Pharmacokinetics in the Treatment of Pulmonary Tuberculosis Using Isoniazid and Levofloxacin

To evaluate the methodology for rapidly determining the early bactericidal activity (EBA), tolerance, and pharmacokinetics of isoniazid and levofloxacin in the treatment of pulmonary tuberculosis (TB). Traditionally, in trials for treatment of TB, a new drug is administered in combination with two or more other antituberculous agents of known effectiveness over a long period of time. In this setting, it is difficult to determine the effect of any single drug or dose level. Development of new agents for the treatment of TB may be accelerated by a methodology in which a new agent could be evaluated for activity by administering it as a single agent over a short time period. This study utilizes a method to measure the amount of bacteria present each day in the lungs. Traditionally, in trials for treatment of TB, a new drug is administered in combination with two or more other antituberculous agents of known effectiveness over a long period of time. In this setting, it is difficult to determine the effect of any single drug or dose level. Development of new agents for the treatment of TB may be accelerated by a methodology in which a new agent could be evaluated for activity by administering it as a single agent over a short time period. This study utilizes a method to measure the amount of bacteria present each day in the lungs. An initial cohort of patients receive isoniazid (with pyridoxine) daily for 5 days. Sputum samples are collected daily for determination of the EBA (decline in colony-forming units/ml sputum). If the methodology is validated, additional patients are randomized to receive one of two doses of levofloxacin daily for 5 days, with determination of EBA. All patients are hospitalized for 2 days of baseline evaluation and 5 days of treatment.