The efficacy and safety of levofloxacin in the treatment of respiratory tract infections

28 October, 2020

Professor Ngô Quý Châu
President of Vietnam Respiratory Society
Head of Respiratory Department, Tam Anh Hospital Hanoi, Vietnam.


The high-dose, short-course regimen of 750 mg levofloxacin once daily for 5 days is as effective as 500 mg of levofloxacin per day for 10 days for the treatment of community-acquired pneumonia (CAP).1 In patients with respiratory infections, the 5-day regimen of 750 mg of levofloxacin per day was well tolerated with a similar side-effect profile to the standard 10-day regimen of 500 mg of levofloxacin per day.2,3

Professor Ngô Quý Châu, President of Vietnam Respiratory Society, head of Respiratory Department, Tam Anh Hospital Hanoi, Vietnam discusses the efficacy and safety of the high-dose, short-course levofloxacin regimen for the treatment of respiratory tract infections (RTIs).


Q1: What are the current guideline recommendations for high-dose, short-course levofloxacin in the treatment of RTIs?

The Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) guidelines 2007 recommend monotherapy with a respiratory fluoroquinolone.4 The use of high-dose, short course levofloxacin in this guideline is recommended as an effective treatment of RTIs. Clinicians typically use respiratory quinolones such as levofloxacin for the empirical treatment of RTIs caused by penicillin-resistant Streptococcus pneumoniae (PRSP). The emergence of antimicrobial resistance to commonly used antibiotics for CAP represents a challenge for effective treatment with beta-lactam antibiotics. Thus, levofloxacin is often a preferred choice; the short duration of treatment is also an advantage when using a high-dose, short course levofloxacin.


Q2. Can you share with us the clinical or microbiologic efficacy of the high-dose, short-course levofloxacin regimen?

Levofloxacin has a broad spectrum of antibacterial activity that encompasses numerous Gram-positive and Gram-negative aerobes and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila).

High-dose, short-course levofloxacin is commonly indicated for mild or moderate CAP and it is used for treatment of patients with comorbidities, severe airway obstruction or recurrent exacerbations. I have been prescribing high-dose, short-course levofloxacin for patients with pneumonia and infections following exacerbation of chronic obstructive pulmonary disease. Of course, we have to consider and rule out a differential diagnosis of tuberculosis.


Q3. What are the common side effects seen in your patients on a high-dose, short-course treatment of levofloxacin? How would you manage treatment-emergent adverse events?

Levofloxacin is generally well tolerated in patients with RTI. The most common side effects include headache, nausea, vomiting, dizziness and constipation. Although severe nausea is rare, I would discontinue the treatment if patients experience such a side effect.


Q4. What are the potential short-term outcomes or the long-term side effects of high-dose, short-course levofloxacin when treating respiratory infections?

The common short-term side effects are dizziness, vomiting, nausea and constipation. Tendinitis is a rare complication.

The long-term side effects may include liver function impairment and kidney injury. As we use levofloxacin for only a short period of time (5–14 days), we have not recorded any cases of long-term side effects.


Q5. In special patient subgroups such as the elderly or those with underlying renal impairment, are there any precautions or considerations for treating RTIs with a high-dose, short-course of levofloxacin?

Elderly patients may be more sensitive to levofloxacin. The U.S. Food and Drug Administration (FDA) added a ‘black box’ warning to fluoroquinolones in 2008 for the increased risk of tendinitis and tendon rupture.5 The FDA reported higher risks of tendinitis and tendon rupture in people aged above 60 years, patients who had received kidney, heart, or lung transplants, and people receiving steroid treatment.

Patients with impaired renal function taking levofloxacin 750 mg once daily for 5 days will also require dosage adjustments.

We have to consider carefully indication of levofloxacin in children due to the increase risk of musculoskeletal adverse effects.6,7 The use of levofloxacin will be stopped when there is redness and swelling in the tendon (Achilles tendon is the most common tendon affected).



  1. Dunbar LM, et al. Clin Infect Dis 2003;37:752-760.
  2. Anderson VR and Perry CM. Drugs 2008;68:535-565.
  3. Torres A and Liapikou A. Expert Opin Pharmacother 2012;13:1203-1212.
  4. Mandell LA, et al. Clin Infect Dis 2007;44:S27–S72.
  5. Tanne JH. BMJ 2008;337:a816.
  6. Kim Y, et al. Sci Rep 2019 279:20156.
  7. Mathews B, et al. Antibiotics 2019;8:104.