Levofloxacin
Pronunciation: lee-voe-FLOX-a-sin.
- Generic name
- levofloxacin
- Drug class
- Fluoroquinolone antibacterial
- Form
- Tablet or injection, depending on the product
- Route
- Oral or intravenous, depending on the product
- Legal status
- Prescription-only medicine.
Availability and supply rules vary by country
Trade names by country: Canada
Australia: · Full directory
Boxed warning: Disabling and potentially irreversible reactions
Fluoroquinolone antibacterial medicines, including levofloxacin, are associated with disabling and potentially irreversible serious adverse reactions affecting tendons, muscles, joints, nerves, and the central nervous system that can occur together. Levofloxacin can also exacerbate muscle weakness in people with myasthenia gravis. For uncomplicated urinary tract infection, acute bacterial exacerbation of chronic bronchitis, and acute bacterial sinusitis, levofloxacin should be reserved for patients who have no alternative treatment options, given these risks. (1) (2)
What levofloxacin is and how it works
Levofloxacin is a fluoroquinolone antibiotic used for certain bacterial infections caused by susceptible organisms. (1)
Because of a real risk of disabling and sometimes irreversible tendon, nerve, and central nervous system effects, levofloxacin is reserved for infections where alternative antibiotics are not suitable, particularly for uncomplicated urinary tract infection, bronchitis flare-ups, and sinusitis.
Mechanism of action: how levofloxacin works
Levofloxacin is a fluoroquinolone that inhibits bacterial DNA gyrase and topoisomerase IV, disrupting bacterial DNA replication. (1)
What levofloxacin is used for
Susceptible bacterial infections
Used for certain bacterial infections caused by susceptible organisms, as defined by the current product label. For uncomplicated urinary tract infection, acute bacterial exacerbation of chronic bronchitis, and acute bacterial sinusitis specifically, it is reserved for patients with no alternative treatment options. (1)
Before taking levofloxacin
Do not take / not appropriate for
- Do not take levofloxacin if you have had a hypersensitivity reaction to levofloxacin or another fluoroquinolone antibiotic. (all products) (1)
- Do not take levofloxacin if you have myasthenia gravis, unless your prescriber specifically judges the benefit outweighs the risk, since it can worsen muscle weakness in this condition. (all products) (1)
Tell your clinician about
- Any tendon problems, including a previous tendon rupture with a fluoroquinolone antibiotic.
- Myasthenia gravis or any nerve or muscle-weakness condition.
- Any heart-rhythm problem, family history of long QT syndrome, or low blood potassium.
- An aortic aneurysm or a family history of aneurysm or connective-tissue conditions.
- Diabetes, since blood sugar can be affected.
- Kidney disease, since the dose is adjusted for reduced kidney function.
- Every other medicine you take, especially antacids, supplements containing calcium, magnesium, iron, or zinc, and anticoagulants.
- Pregnancy or breastfeeding.
How to take levofloxacin
- Take exactly as prescribed, for the exact indication and duration directed.
- Complete the full prescribed course even if you feel better.
- Separate dosing from antacids and supplements containing calcium, magnesium, iron, or zinc, since these can reduce absorption; ask your pharmacist for the correct timing.
- Avoid excessive sun or UV light exposure, since fluoroquinolones can increase sensitivity to sunlight.
- Do not change your dose or stop taking levofloxacin without talking to your prescriber first, unless a serious reaction requires immediate medical attention.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
Follow the product instructions for missed doses, or ask your prescriber or pharmacist. do not take an extra dose to make up for a missed one.
Overdose
Contact your prescriber, pharmacist, or a poison-control/emergency service if an overdose is suspected.
Side effects
Digestive symptoms are commonly reported, but levofloxacin carries several serious risks that need prompt attention rather than being managed as routine side effects.
Nausea, diarrhoea, or headache
What to notice: Commonly reported effects.
What to do: Tell your prescriber if severe or persistent. (1)
Nausea and vomiting
Incidence: Common
Headache
Incidence: Common
Tendon pain or swelling
What to notice: Pain, swelling, or inflammation in a tendon, especially the Achilles tendon.
What to do: Stop physical activity involving the affected area and contact your prescriber promptly; tendon rupture can occur, sometimes without warning. (1)
Nerve symptoms
What to notice: Numbness, tingling, burning, or weakness, which can appear soon after starting treatment.
What to do: Contact your prescriber promptly; this can indicate peripheral neuropathy that may become irreversible. (1)
Central nervous system symptoms
What to notice: Seizures, confusion, tremors, anxiety, disturbed sleep, or thoughts of self-harm.
What to do: Contact your prescriber promptly, or seek emergency help for any thoughts of self-harm. (1)
Persistent diarrhoea
What to notice: Watery or bloody diarrhoea, possibly with fever and stomach cramps, occurring during or after treatment.
What to do: Contact your prescriber promptly; do not treat with an anti-diarrhoeal medicine without medical advice, since this can indicate a serious antibiotic-associated condition. (1)
Serious warnings
Tendon rupture — urgent
Symptoms: Sudden pain, swelling, bruising, or inability to bear weight, especially in the Achilles tendon.
Action: Seek prompt medical attention and avoid using the affected area; risk is higher in older adults and those taking corticosteroids. (1)
Aortic aneurysm or dissection — emergency
Symptoms: Sudden, severe chest, abdominal, or back pain.
Action: Seek emergency medical help immediately. (1)
Heart-rhythm problem (QT prolongation) — emergency
Symptoms: Fast or irregular heartbeat, fainting, or severe dizziness.
Action: Seek emergency medical help immediately. (1)
Severe allergic reaction — emergency
Symptoms: Swelling of the face, lips, tongue, or throat, difficulty breathing, or severe rash.
Action: Seek emergency medical help immediately. (1)
Blood sugar changes — urgent
Symptoms: Symptoms of very low or very high blood sugar, particularly in people with diabetes.
Action: Monitor blood sugar as advised and seek prompt medical attention for symptoms of severe blood sugar changes. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Antacids and supplements containing calcium, magnesium, iron, or zinc | Can significantly reduce absorption of levofloxacin. | Separate dosing timing as directed by your pharmacist. (1) |
| Anticoagulants (e.g. warfarin) | Levofloxacin may enhance the effect of anticoagulants, increasing bleeding risk. | Your prescriber may monitor clotting tests more closely. (1) |
| Corticosteroids | Combined use increases the risk of tendon problems, especially in older adults. | Tell your prescriber if you take a corticosteroid. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Kidney impairment
The dose is adjusted according to kidney function; your prescriber will set the correct dose and interval. (1)
Older adults
Older adults, especially those also taking corticosteroids, have a higher risk of tendon problems. (1)
Children
Paediatric use is limited to specific, narrow indications defined by the product label; adult use must not be extrapolated to children. (1)
Pregnancy and breastfeeding
Discuss the balance of benefits and risks with your prescriber before starting, stopping, or continuing levofloxacin in pregnancy or while breastfeeding. (1)
Monitoring
Before starting
- Confirm the diagnosis and that levofloxacin is appropriate given the boxed-warning risks, particularly for uncomplicated UTI, bronchitis flare-up, or sinusitis, where alternative treatment should be considered first.
- Review tendon history, myasthenia gravis, cardiac risk factors, diabetes, kidney function, and all current medicines.
During treatment
- Watch for tendon, nerve, central nervous system, cardiac, and blood-sugar warning signs.
- Complete the full prescribed course.
Storage
Store as directed on the product label, out of reach of children.
Study the drug class: Fluoroquinolones
Professional information
Clinician-facing context only. Use the current local product information for exact dosing and renal adjustment; reserve use for uncomplicated UTI, acute bacterial exacerbation of chronic bronchitis, and acute bacterial sinusitis per antimicrobial-stewardship guidance.
United States
Indication: Susceptible bacterial infections
Dose summary: No universal dose is displayed; dosing depends on indication and renal function. Use the current local product information.
Renal context: Dose adjustment required based on creatinine clearance; use current local product information. (1)
Hepatic guidance
Hepatotoxicity has been reported; monitor for signs of liver injury.
Overdose note
Manage suspected overdose supportively per local poison-control and emergency guidance. (1)
Frequently asked questions
What is levofloxacin used for?
levofloxacin is prescribed for approved indications. Always follow your healthcare provider's guidance.
What are the side effects of levofloxacin?
Common side effects may include gastrointestinal symptoms and headache. Serious side effects require immediate medical attention.
Can I take levofloxacin with other medications?
Always inform your healthcare provider about all medications you are taking, including over-the-counter products and supplements.
What is the mechanism of action of levofloxacin?
Levofloxacin is a fluoroquinolone that inhibits bacterial DNA gyrase and topoisomerase IV, disrupting bacterial DNA replication. (1)
References
- Levofloxacin tablets, USP — prescription drug labelU.S. National Library of Medicine DailyMed · United States · dated 2026-06-29 · accessed 2026-07-22 · source 1
- More prominent warnings about serious side effects for fluoroquinolone antibioticsTherapeutic Goods Administration · Australia · dated 2025-03-07 · accessed 2026-07-22 · source 2
- LEVOFLOXACIN INJECTION, SOLUTION [SAGENT PHARMACEUTICALS] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Levofloxacin — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
- Levofloxacin — FDA approval record (Drugs@FDA ANDA202801)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
- levofloxacin — RxNorm normalized drug concept (RXCUI 82122)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient levofloxacin names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
Canada
- LEVOFLOXACIN IN 5% DEXTROSE
- QUINSAIR