Antibiotic resistance and the role of high-dose, short-course levofloxacin in the treatment of pneumonia

23 December, 2019

Associate Professor Dr Tran Van Ngoc, MD, PhD

President of Ho Chi Minh City Respiratory Association

Head of Respiratory Department of Cho Ray Hospital


Excessive exposure to antibiotics was identified as one of the factors that contributes to the emergence of antimicrobial-resistant bacteria.1 The health threat of antimicrobial-resistant bacteria prompts us to find ways to limit our exposure to antibiotics. One strategy is the use of high-dose, short-course regimens, instead of conventional, longer-course regimens of antibiotic.2

By maximising its concentration-dependent bactericidal activity, levofloxacin is one of the antibiotics available for use in a high-dose, short-course antibiotic regimen (750 mg daily for 5 days).3,4 Besides reducing the risk of bacterial resistance, this regimen also improves patients’ compliance due to the reduced duration of treatment.

Associate Professor Dr Tran Van Ngoc, a pulmonology expert and Head of the Respiratory Department of Cho Ray Hospital was invited as the clinical expert for this interview to discuss the role of levofloxacin in the treatment of pneumonia.


Q1: What is the local prevalence of community-acquired pneumonia (CAP) and healthcare-acquired pneumonia (HCAP)? How many of them are treated in the outpatient setting?

A1: CAP and HCAP account for about 30% and 10% of infectious diseases in Vietnam, respectively. About 80% of pneumonia cases are treated in the outpatient setting.


Q2: Based on your clinical experience, how frequent do you encounter cases of pneumonia caused by antibiotic-resistant pathogens? What is your opinion on the use of high-dose, short-course antibiotics as a strategy to reduce the emergence of antimicrobial-resistance?

A2: In my opinion, the use of high-dose, short-course antibiotics might be a good strategy to reduce antibiotic resistance among common pathogens such as Streptococcus pneumoniae or Haemophilus influenzae. However, pneumonia caused by Klebsiella pneumoniae or Pseudomonas aeruginosa may require a longer duration regimen or a combination therapy since these Gram-negative pathogens are usually resistant to antibiotics. Based on current my experience, about 30% of CAP have been caused by antibiotic-resistant pathogens.


Q3: What are the current outpatient levofloxacin regimens available at your centre? Is high-dose, short-course levofloxacin (750 mg daily for 5 days) commonly used in your centre for outpatient treatment of pneumonia?

A3: Currently, we are using outpatient regimen of levofloxacin 750 mg once daily for 5–7 days to treat mild-to-medium CAP or acute exacerbation of chronic obstructive pulmonary disease. Levofloxacin 500 mg regimens are not in use anymore.


Q4: What are the common levofloxacin side effects seen in your centre? Are there any differences between the side effects seen in high-dose, short-course and those in conventional levofloxacin regimens? If yes, please expound on your answer.

A4: Based on my clinical experience, there is no differences between side effects related to high-dose, short-course levofloxacin and those related to conventional levofloxacin regimens.


Q5: Are there any reported cases of QT prolongation associated with the use of levofloxacin or moxifloxacin in your centre? How do the side effects impact your choice between levofloxacin and moxifloxacin, particularly for treatment in elderly patients?

A5: QT prolongation is a rare side effect of levofloxacin and moxifloxacin use. I have never encountered any case of QT prolongation associated with the use of levofloxacin or moxifloxacin during my clinical practice. The choice between levofloxacin or moxifloxacin would depends on the causative pathogens. For example, if Gram-negative bacteria has not been ruled out, the first-choice antibiotic would be levofloxacin.



  1. Chokshi A, et al. J Glob Infect Dis 2019;11:36–42.
  2. Spellberg B, Rice LB. Ann Intern Med 2019;171:210–211.
  3. Anderson VR, Perry CM. Drugs 2008;68:535–565.
  4. Chen CW, et al. Infect Drug Resist 2019;12:1353–1361.