Drug reference

Norfloxacin

Fluoroquinolone antibiotic · Antibiotic

Also known as Norfloxacin hydrochloride

START

400 mg BD; take with plenty of fluids; avoid antacids within 2 hours

TYPICAL MAX

800 mg/day

STOP IF

Tendon pain/swelling, peripheral neuropathy symptoms, severe rash, QT prolongation

WATCH

Tendon symptoms, glucose (dysglycemia in diabetics), QTc if cardiac risk, C. difficile if diarrhea develops

CDSCO approvedJan AushadhiNPPA price-controlledATC J01MA06

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 1h · Rapid bactericidal onset
PEAK: 1.5h · Peak plasma concentration
t½: 3.5h · Elimination half-life
DURATION: 12h · 12-hour dosing interval

EXCRETION

Renal and fecal (~30% each)

route + CYP

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

Contraindicated in pregnancy - risk of fetal cartilage and joint damage

FDA category + note

Top interactionssee all 12 →

CelecoxibSevereTextbook-citedKDT 7e · p949
DiclofenacSevereTextbook-citedKDT 7e · p949
IbuprofenSevereTextbook-citedKDT 7e · p949
IndomethacinSevereTextbook-citedKDT 7e · p949

Available in India

153 branded formulations and 219 fixed-dose combinations. Look up specific brands in the Drugs workspace.

Jan Aushadhi — generic available at GoI pharmacies

Mechanism

Inhibition of bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, preventing DNA replication, transcription, and repair in susceptible bacteria

Indications

Uncomplicated urinary tract infectionsProstatitis (chronic bacterial)Gonococcal urethritis (when susceptibility confirmed)Traveler's diarrheaGastroenteritis (shigellosis, salmonellosis)

Dosing

Adult: UTI: 400 mg BD for 3-7 days; Prostatitis: 400 mg BD for 4-6 weeks; Gonorrhea: 800 mg single dose; Gastroenteritis: 400 mg BD for 5 days
Pediatric: Contraindicated under 18 years (risk of arthropathy)
Renal adjustment: CrCl 30-50: 400 mg OD; CrCl <30: 400 mg every 24-48h
Hepatic adjustment: No adjustment needed in mild-moderate; caution in severe
Geriatric: Standard dosing with renal adjustment; increased risk of tendonitis and QT prolongation
Max dose: 800 mg/day

Pharmacokinetics

Onset

Rapid bactericidal effect

Peak effect

1-2 hours (Tmax)

Duration

12 hours

Half-life

3-4 hours

Bioavailability

30-40% (lower than other fluoroquinolones)

Protein binding

10-15%

Metabolism

Hepatic (minimal; ~30% metabolized)

Excretion

Renal (~30% unchanged; fecal ~30%)

Contraindications

History of tendon disorders related to fluoroquinolone use
QT prolongation or concurrent QT-prolonging medications
Epilepsy or lowered seizure threshold
Pregnancy and breastfeeding
Children and adolescents under 18 years
Hypersensitivity to norfloxacin or other fluoroquinolones

Side effects

Common

NauseaDiarrheaAbdominal painDizzinessHeadacheInsomniaRashTaste disturbances

Serious

Tendonitis and tendon rupture (black box warning)
Peripheral neuropathy (may be irreversible)
QT prolongation and torsades de pointes
CNS effects (seizures, psychosis)
Aortic aneurysm/dissection risk
Hepatotoxicity
Severe hypersensitivity reactions
Clostridioides difficile-associated diarrhea

Pregnancy & lactation

Pregnancy

Contraindicated in pregnancy - risk of fetal cartilage and joint damage

Lactation

Excreted in breast milk; contraindicated during breastfeeding