Early and extended early bactericidal activity of levofloxacin, gatifloxacin and moxifloxacin in pulmonary tuberculosis

Int J Tuberc Lung Dis. 2006 Jun;10(6):605-12.


Objective: To evaluate the early bactericidal activity (EBA) of the new fluoroquinolones levofloxacin, gatifloxacin and moxifloxacin in patients with pulmonary tuberculosis (PTB).

Design: Randomized, open-label trial. Forty adults with newly diagnosed smear-positive PTB (10 per arm) were assigned to receive isoniazid (INH) 300 mg, levofloxacin 1000 mg, gatifloxacin 400 mg, or moxifloxacin 400 mg daily for 7 days. Sputum for quantitative culture was collected for 2 days before and daily during 7 days of monotherapy. Bactericidal activity was estimated by measuring the decline in bacilli during the first 2 days (EBA 0-2) and last 5 days of monotherapy (extended EBA, EBA 2-7). Laboratory staff were blinded to treatment assignment.

Results: The EBA 0-2 of INH (0.67 log10 cfu/ml/day) was greater than that of moxifloxacin and gatifloxacin (0.33 and 0.35 log10 cfu/ml/day, respectively), but not of levofloxacin 1000 mg daily (0.45 log10 cfu/ml/day) (P = 0.14). Bactericidal activity between days 2 and 7 was similar for all three fluoroquinolones. In a pooled comparison, the EBA 2-7 of the fluoroquinolones was greater than for INH.

Conclusion: Moxifloxacin, gatifloxacin, and high-dose levofloxacin have excellent EBA, only slightly less than for INH, and greater extended EBA. These drugs warrant further study in the treatment of drug-susceptible TB.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Anti-Bacterial Agents / therapeutic use*
  • Anti-Infective Agents / therapeutic use*
  • Aza Compounds / therapeutic use*
  • Female
  • Fluoroquinolones / therapeutic use*
  • Gatifloxacin
  • Humans
  • Levofloxacin*
  • Male
  • Middle Aged
  • Moxifloxacin
  • Ofloxacin / therapeutic use*
  • Quinolines / therapeutic use*
  • Single-Blind Method
  • Tuberculosis, Pulmonary / drug therapy*


  • Anti-Bacterial Agents
  • Anti-Infective Agents
  • Aza Compounds
  • Fluoroquinolones
  • Quinolines
  • Levofloxacin
  • Ofloxacin
  • Gatifloxacin
  • Moxifloxacin