Levofloxacin
A fluoroquinolone antibiotic used for pneumonia, urinary and kidney infections, skin infections and drug-resistant tuberculosis.
Drug card
- Class
- Fluoroquinolone
- How it works
- Blocking DNA gyrase and topoisomerase IV, so bacteria cannot copy their DNA
- Used for
- Pneumonia, community or hospital acquired
- Complicated urinary and kidney infections
- Skin and soft tissue infections
- Drug-resistant tuberculosis
- Known for
- Tendinitis and tendon rupture
- Its name
- -floxacin means a fluoroquinolone antibiotic
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does levofloxacin work?
The L-isomer of ofloxacin, which carries that drug's antibacterial activity. It blocks DNA gyrase and topoisomerase IV and covers Streptococcus pneumoniae, including multidrug-resistant strains, as well as many Gram-negative bacteria. The kidneys clear it, so its dose is lowered in kidney disease.
Like other fluoroquinolones: Fluoroquinolones block DNA gyrase and topoisomerase IV, two bacterial type II topoisomerases (gyrase is topoisomerase II). The bacterium needs both to copy, transcribe and repair its DNA, so blocking them halts DNA replication and kills the cell: the drugs are bactericidal. Bacteria resist them mainly through gyrase mutations, a less permeable outer membrane or efflux pumps.
Uses
What is levofloxacin used for?
- Pneumonia, community or hospital acquired
- Complicated urinary and kidney infections
- Skin and soft tissue infections
- Drug-resistant tuberculosis
Side effects
Side effects of levofloxacin
- Tendinitis and tendon ruptureKnown forSerious
- Nausea
- Headache
- Diarrhea
- Trouble sleeping (insomnia)
- Constipation
- Dizziness
- Peripheral neuropathySerious
- SeizuresSerious
- Mood changes and psychosisSerious
- Severe liver injurySerious
- Long QT intervalSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Kidney disease: the dose is lowered, because the drug builds up when the kidneys clear it slowly.
- Avoid with other QT-prolonging drugs, such as class IA or III antiarrhythmics, and with uncorrected low potassium.
- Space doses apart from antacids, iron, zinc and other products containing metal ions.
Good to know: With moxifloxacin, it is one of the two fluoroquinolones WHO recommends in regimens for drug-resistant tuberculosis.
Remember it
A way to remember it
STAMP
- S
- Sugar swings: low or high blood sugar
- T
- Tendinitis and tendon rupture
- A
- Aortic aneurysm or dissection
- M
- Myasthenia gravis made worse
- P
- Peripheral neuropathy
Fluoroquinolones can leave a STAMP on the body: these are the serious harms in their label warnings.
Written for biofideX
Its name
-floxacin means fluoroquinolone antibiotic
WHO's stem is -oxacin (quinolones); -floxacin is its fluorinated subgroup: ciprofloxacin, levofloxacin, moxifloxacin. Nalidixic acid, the parent quinolone, has no stem.
- Every drug name stem
Its class
Fluoroquinolones
Other fluoroquinolones with a card:
Easily mixed up with topoisomerase II inhibitors and tetracyclines.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Levofloxacin tablets: label (DailyMed)
- Levofloxacin (NCI Thesaurus)
- WHO consolidated guidelines on tuberculosis: module 4: treatment and care, 2nd edition (WHO)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antibiotics: DNA, folate and tuberculosis
Levofloxacin is one of 11 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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