iMedix Medical Content Engine 3.13.37
Home/Drugs/Levaquin (Levofloxacin)

Levaquin (Levofloxacin): Uses, Dosage & Safety Information

Levaquin (Levofloxacin)

Levaquin (Levofloxacin)
levaquin 250 mg
1 / 3

Levaquin (Levofloxacin)

Levofloxacin
Levaquin was the brand of levofloxacin, a prescription fluoroquinolone antibacterial now supplied as generics. Alongside its boxed warning about tendon, nerve and CNS reactions, it can cause both low and high blood sugar, particularly in people with diabetes treated with insulin or oral medicines.
  • ActiveIngredient: Levofloxacin
  • DosageForm: Film-coated tablet
  • Dosage: 250 mg, 500 mg, 750 mg
  • Indications: Nosocomial and community-acquired pneumonia, skin and skin structure infections, chronic bacterial prostatitis, urinary tract infections, acute pyelonephritis, bronchitis exacerbation, sinusitis, inhalational anthrax post-exposure and plague
  • Manufacturer: Generic manufacturers; brand Levaquin no longer marketed
  • Storage: Store as directed on the dispensed container; keep out of reach of children
  • Drug Status: Discontinued
Drug Status: Discontinued
Description

What is Levaquin?

Blood sugar can swing either way
Fluoroquinolones, including levofloxacin, have caused both high and low blood sugar, usually in people with diabetes taking insulin or tablets such as glyburide; severe low blood sugar has led to coma and death.1

Levaquin was the Janssen brand of levofloxacin, a prescription fluoroquinolone antibacterial. The brand is no longer marketed, and levofloxacin is supplied as generic tablets, oral solution and injection.24

Like other fluoroquinolones it carries a boxed warning about disabling tendon, nerve and central nervous system reactions and about myasthenia gravis.1

Its effect on blood sugar is the risk most easily overlooked, because it affects people who are otherwise well controlled on their diabetes treatment.

General Instructions

How to Take Levaquin

Once a day

Take one dose every 24 hours at about the same time, with or without food, with plenty of fluid.1

How much

Doses of 250 mg to 750 mg once daily are used, for 3 to 14 days in most infections, and 60 days after anthrax exposure. Children of 30 kg or more may take tablets; lighter children need another form.1

If you have diabetes

Check your blood sugar more often during the course, and know the signs of both low and high readings. Keep glucose tablets or a sugary drink to hand.1

Keep antacids apart

Take it at least 2 hours before or after antacids with magnesium or aluminium, sucralfate, iron, zinc or multivitamins with minerals.1

Storage

Store at 20 to 25°C (68 to 77°F).1

What not to do

Do not continue if tendon pain, numbness or confusion appears; stop and call the prescriber.

Side Effects

What Are the Side Effects of Levaquin?

Besides nausea, headache and diarrhoea, the labelling details serious reactions that can occur even after a short course.1

Reactions in the Labelling
FrequencyEffectNotes
CommonNausea, headache, diarrhoeaMost common in trials
CommonInsomnia, constipation, dizzinessReported in trials
Frequency not stated in labellingLow or high blood sugarMostly in treated diabetes
Frequency not stated in labellingTendinitis and tendon ruptureBoxed warning
Frequency not stated in labellingQT prolongationRare

Source: 1

Seek immediate medical attention if:
  • Sweating, shakiness, confusion or fainting (low blood sugar)
  • Pain, swelling or a snap in a tendon
  • Palpitations or fainting
Uses

What is Levaquin Used For?

Labelled Indications
IndicationNotes
Pneumonia (hospital- and community-acquired)Susceptible organisms
Skin and skin structure infectionsSusceptible organisms
Chronic prostatitis and complicated urinary infectionsIncluding acute pyelonephritis
Inhalational anthrax and plagueAfter exposure, adults and children
Sinusitis, bronchitis flares, uncomplicated cystitisOnly when no alternative exists

Source: 1

For mild infections the labelling reserves levofloxacin for patients with no other treatment option, because of its serious risks.1

Safety Advice

Interactions Alcohol:

Consult your doctor
The label sets no alcohol restriction. Alcohol adds to the central nervous system effects named in the boxed warning, and in diabetic patients it compounds the risk of low blood sugar this drug can cause.

Interactions Other Medications:

Unsafe
Antacids, iron, zinc, calcium and mineral-containing multivitamins bind levofloxacin in the gut and can make treatment fail unless separated by at least two hours. Insulin and oral hypoglycaemics carry a risk of severe hypoglycaemia. Corticosteroids raise tendon rupture risk, and NSAIDs may increase seizure risk.

Special Groups Pregnancy:

Consult your doctor
The prescribing information does not set a blanket recommendation. Fluoroquinolones are generally avoided in pregnancy where alternatives exist; anthrax and plague exposure are the situations where that changes.

Special Groups Breastfeeding:

Consult your doctor
The label does not establish a breastfeeding recommendation. The decision belongs to the clinician treating the infection.

Special Groups Elderly:

Use with caution
Age over 60 is a named risk factor for tendinitis and tendon rupture, and the risk compounds with corticosteroids. Renal clearance also declines with age, and levofloxacin is cleared by the kidney.

Special Groups Children:

Use with caution
Paediatric use is restricted to specified infections, and tablets cannot be given below 30 kg because the available strengths do not divide that far. A different formulation is needed for smaller children.

Effects on Activities Driving:

Use with caution
The boxed warning covers confusion, agitation and seizures, reported even after a single dose. In diabetic patients, hypoglycaemia adds a second reason to be careful behind the wheel.

Effects on Activities Operating Machinery:

Use with caution
The same central nervous system effects apply, and tendon injury adds a concern for tasks requiring physical exertion.
Regulatory status and dispensing

Levaquin is discontinued; levofloxacin is prescription-only and supplied as generics.2

Warnings

Critical Warnings for Levaquin Use

Boxed warning
Fluoroquinolones have caused disabling and potentially irreversible tendinitis, tendon rupture, peripheral neuropathy and CNS effects, and may exacerbate muscle weakness in myasthenia gravis.1

Quinolone hypersensitivity

Contraindicated: Known hypersensitivity to levofloxacin or other quinolone antibacterials.1

Blood glucose disturbances

Hypoglycemia and hyperglycemia have been reported, mostly in diabetes treated with insulin or oral agents; treatment stops if hypoglycemia occurs.1

Tendons, nerves, CNS and myasthenia gravis

These serious reactions can occur together; treatment stops at the first sign.1

See Interactions.

Dosage

Dosage

Levaquin Products
FormulationActive IngredientsClinical Note
Tablets 250 mg, 500 mg, 750 mgLevofloxacinGeneric; Levaquin brand discontinued
Renal impairment, creatinine clearance 20 to 49 mL/minLevofloxacinLonger interval between doses
Renal impairment below 20 mL/min or on dialysisLevofloxacinReduced follow-on doses every 48 hours
Hepatic impairmentLevofloxacinNo adjustment expected; severe liver injury reported

Source: 14

Exceeding the dose
Overdose is managed supportively with hydration and ECG monitoring; haemodialysis and peritoneal dialysis do not remove it effectively.1
Interactions

What Does Levaquin Interact With?

For people with diabetes, the second row is the one to discuss before the first dose.

Interactions by Severity
Interacting SubstanceEffect and RiskSeverityDocumentation
Antacids, sucralfate, iron, zinc, multivitamins with mineralsMuch lower levofloxacin absorptionModerateGood — labelled interaction
Insulin and oral diabetes medicinesLow or high blood sugarMajorGood — labelled interaction
WarfarinStronger anticoagulant effectMajorGood — labelled interaction
NSAIDsHigher risk of seizuresModerateGood — labelled interaction
TheophyllineSeizure risk with high levelsModerateGood — labelled interaction

Source: 1

FAQs
The Levaquin brand is no longer marketed; prescriptions are filled with generic levofloxacin.
Yes. It can cause low or high blood sugar, mostly in people with diabetes on insulin or tablets.
Check your blood sugar and treat a low reading; tell the prescriber, because treatment may need to stop.
Separate them by at least 2 hours, because minerals block absorption.
Its serious tendon, nerve and CNS risks outweigh the benefit when other options exist.
Evidence and Reported Data

Evidence Scope

Established: fluoroquinolones can cause both low and high blood sugar, mainly in treated diabetes. Unknown: individual risk, which cannot be predicted from previous courses.1

What has been reported to the FDA

As of the FAERS data cut of 30 July 2026, the FDA Adverse Event Reporting System held 37,010 reports naming Levaquin, of which 28,670 were classed as serious — 77% of the total.3

Most Reported Terms
Coded termReports
Pain2,813
Arthralgia2,705
Drug hypersensitivity2,685
Peripheral neuropathy2,406
Nausea2,200
Pain in extremity2,097
How to read this table

FAERS records what was reported, not what the medicine caused, and has no denominator – no count can become a rate.

Figures above are the counts held at the 30 July 2026 data cut, retrieved on 3 September 2026; they do not update between cuts.

Population note: four of the six leading terms — pain, arthralgia, peripheral neuropathy and pain in extremity — describe musculoskeletal and nerve symptoms, and together they outnumber the gastrointestinal complaints that usually dominate antibacterial reporting. This is an even closer match to the boxed warning than ciprofloxacin shows. Two cautions apply: reports cluster around drugs that attract public attention and litigation, which inflates volume without proving causation, and the brand name persists in reports long after the brand left the market.

Who was this medicine studied in?

Levaquin was approved in 1996, before the Drug Trials Snapshots programme.5

Where to report and verify

Routing to Official Registries
What you needWhere to go
Report a side effectFDA MedWatch
Pregnancy-specific dataMotherToBaby
Full prescribing informationDailyMed
Verify a pharmacy websiteFDA BeSafeRx · LegitScript
References

References

  1. FDA Prescribing Information, levofloxacin tablets USP (ANDA 202801) — Boxed Warning, Indications and Usage, Dosage and Administration incl. Table 3, Contraindications, Warnings and Precautions 5.1–5.13, Adverse Reactions, Drug Interactions
    Label effective 2025-03-04 · Accessed 2026-09-28
    Used for: blood glucose warning, dosing and renal table, boxed warnings, interactions.
    dailymed.nlm.nih.gov — DailyMed
  2. Drugs@FDA — Levaquin (NDA 020634) and levofloxacin applications
    Records · Accessed 2026-09-28
    Used for: brand discontinuation and generic supply.
    accessdata.fda.gov — Drugs@FDA
  3. openFDA — FDA Adverse Event Reporting System, drug event query for levofloxacin
    Data cut 2026-07-30 · Accessed 2026-09-28
    Used for: report totals, serious counts and most reported terms.
    open.fda.gov — openFDA
  4. FDA Orange Book — levofloxacin
    Current edition · Accessed 2026-09-28
    Used for: reference-standard and generic availability.
    accessdata.fda.gov — Orange Book
  5. FDA — Drug Trials Snapshots programme scope
    Programme current · Accessed 2026-09-28
    Used for: confirmation that Snapshots cover novel drugs approved from 2015.
    fda.gov — Drug Trials Snapshots

Review cycle. Clinical review completed 28 September 2026. Next review due by 28 September 2027, or earlier if the labelling is revised.

Disclaimer

Disclaimer: The information on this site is provided for informational purposes only and is not medical advice. It does not replace professional medical consultation, diagnosis, or treatment. Do not self-medicate based on the information presented on this site. Always consult with a doctor or other qualified healthcare professional before making any decisions about your health.