Levofloxacin (Levaquin®) vs Ofloxacin (Floxin®)

Based on "Antibiotic and Chemotherapy"
written by Roger G. Finch

Difference between Levofloxacin and Ofloxacin

Levofloxacin and ofloxacin have closely related chemical structures. Ofloxacin represents a racemic mixture of an active and an inactive stereoisomer. Levofloxacin contains solely the active stereoisomer - l-isomer of ofloxacin. As a result both fluoroquinolones have the same spectrum of activity, but levofloxacin has twice the potency of ofloxacin.


Levofloxacin Ofloxacin
• Levaquin®
• Quixin® (ophthalmic)
• Iquix® (ophthalmic)
• Floxin®
• Oflocet®
• Ocuflox® (ophthalmic)
Levaquin dosage forms Floxin dosage forms
Drug class
• Fluoroquinolone antibiotic
Dose formulations
• Tablets
• Oral solution
• Injection
• Ohthalmic solution
• Tablets
• Ohthalmic solution
• Otic solution
FDA-approved indications
• Community-acquired pneumonia (Levofloxacin has two-fold higher bactericidal activity against of S. pneumoniae in comparison with ofloxacin5)
• Acute bacterial exacerbation of chronic bronchitis
• Skin and skin structure infections (uncomplicated)
• Bacterial prostatitis
• Uncomplicated cystitis
• Complicated urinary tract infections
• Bacterial conjunctivitis (ohthalmic solution)
• Corneal ulcers (ohthalmic solution)
• Nosocomial pneumonia
• Complicated skin and skin structure infections
• Complicated urinary tract infections
• Pyelonephritis
• Sinusitis
• Inhalational anthrax, post-exposure
• Uncomplicated gonorrhea
Chlamydial urethritis and cervicitis
• Pelvic inflammatory disease
• Prostatitis
• Otitis media (otic solution)
• Otitis externa (otic solution)
Mechanism of action
• Fluoroquinolones kill bacteria via inhibition of bacterial topoisomerase IV and DNA gyrase enzymes, which are required for DNA replication and transcription.
• 6-8 hours • 4-5 hours
Oral bioavailability
• 100% • 98%
Metabolism, Elimination
• Levofloxacin is eliminated predominantly by the kidneys.
• 80% is excreted as unchanged drug in urine,
less than 4% in feces.
• Ofloxacin is eliminated predominantly by the kidneys.
• 80% is excreted as unchanged drug in urine,
4-8% in feces.
• Hypersensitivity to any quinolone antibiotic
Warnings & precautions
• Tenotoxicity - tendinopathy, tendon rupture. Higher doses and longer duration of fluoroqinolone treatment increase the risk of tendon damage
• Prolongation of the QT interval
• Peripheral neuropathy
• Central nervous system stimulation side effects
Pregnancy category
• C (risk cannot be ruled out)

Levofloxacin vs Ofloxacin for UTIs

Both ofloxacin and levofloxacin are second line choice for the treatment of uncomplicated UTIs4. Both antibiotics have adequate activity against bacteria responsible for UTIs.

Results of comparative study of levofloxacin and ofloxacin in the treatment of complicated UTIs.3 Levofloxacin Ofloxacin
Regimen 300 mg for 10 days 600 mg for 10 days
Response rate 90.0% 88.5%
Clinical efficacy 90% 84.6%
Both antibiotics are effective for complicated UTIs and have comparable safety profiles.

Levofloxacin vs Ofloxacin for Bacterial Conjunctivitis

Results of clinical trial of 0.5% levofloxacin ophthalmic versus 0.3% ofloxacin ophthalmic for the treatment of bacterial conjunctivitis 6 Levofloxacin 0.5% Ofloxacin 0.3%
Regimen Every 2 hours on days 1 and 2 and every 4 hours on days 3-5
Microbial eradication rates at the final visit 89% 80%
Microbial eradication rates at the end point 90% 81%
Efficacy in resolving photophobia 94% 73%

Levofloxacin vs Ofloxacin for Bacterial Keratitis

Ofloxacin and levofloxacin have similar efficacy in the treatment of keratitis, but levofloxacin treatment provides shorter mean cure day of keratitis than ofloxacin7.

Further reading


  • 1. Prescribing Information for Floxin® (Ofloxacin) PDF
  • 2. Prescribing Information for Levaquin® (Levofloxacin) PDF
  • 3. Peng MY. Randomized, double-blind, comparative study of levofloxacin and ofloxacin in the treatment of complicated urinary tract infections. J Microbiol Immunol Infect. 1999 Mar;32(1):33-9.
  • 4. Gupta K, Hooton TM, Naber KG, et al. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011;52(5):e103–e120.
  • 5. Bauernfeind A. Pharmacodynamics of levofloxacin and ofloxacin against Streptococcus pneumoniae. J Antimicrob Chemother. 1999 Jun;43 Suppl C:77-82.
  • 6. Schwab IR, Friedlaender M, McCulley J, Lichtenstein SJ, Moran CT; Levofloxacin Bacterial Conjunctivitis Active Control Study Group. A phase III clinical trial of 0.5% levofloxacin ophthalmic solution versus 0.3% ofloxacin ophthalmic solution for the treatment of bacterial conjunctivitis. Ophthalmology. 2003 Mar;110(3):457-65.
  • 7. Zhang M, Hu Y, Chen F.Clinical investigation of 0.3% levofloxacin eyedrops on the treatment of cases with acute bacterial conjunctivitis and bacterial keratitis. Yan Ke Xue Bao. 2000 Jun;16(2):146-8.

Published: August 25, 2018
Last reviewed: August 25, 2018


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