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Generic

Nalidixic Acid

18 brands available in the market

At a glance

Nalidixic Acid is a 4-quinolone antibiotic used for urinary tract infections and shigellosis. It inhibits bacterial DNA gyrase enzyme to prevent DNA replication.

Description

Nalidixic acid is a synthetic narrow spectrum antibacterial. It is bacteriostatic or bactericidal depending on concentration. It acts by inhibiting bacterial DNA synthesis, possibly by interfering with DNA polymerization. It is rapidly and completely absorbed from the GI tract and distributed to most tissues specially to kidney and urine.

Indications
  • Urinary tract infections (caused by Proteus, Klebsiella, Enterobacter, E. coli)
  • Shigellosis
Therapeutic class

Anti-diarrhoeal Antimicrobial Drugs, Systemic Urinary Anti-infective

Pharmacological class

4-Quinolone Antibiotic

Pharmacology

Nalidixic acid inhibits bacterial DNA gyrase enzyme to prevent DNA replication, resulting in bacterial cell death. It is active against gram-negative bacteria.

Mechanism of action

Treats urinary tract infections by inhibiting bacterial DNA replication.

Dosage

Adult Dose (Oral):

  • Uncomplicated lower UTI: 1 g 4 times daily for 1-2 weeks; long-term: reduce to 2 g/day
  • Shigellosis: 1 g 4 times daily for 5 days

Pediatric Dose (Oral):

  • >3 months: 50 mg/kg daily in 4 divided doses; long-term: 30 mg/kg daily; prophylaxis: 15 mg/kg twice daily
  • Shigellosis: 15 mg/kg 4 times daily for 5 days
Administration
  • Take on empty stomach
  • Use measuring cup
  • Shake well before use
  • Take at the same time each day
Missed dose

If you miss a dose, take it as soon as you remember; skip if it's almost time for next dose; do not double the dose.

Side effects

Common Side Effects:

  • Nausea
  • Vomiting
  • Diarrhea
  • Hemolysis in G6PD deficiency
  • Allergic reactions (urticaria, rash, fever, arthralgia, eosinophilia)
  • Myalgia, muscle weakness
  • Phototoxicity
  • Jaundice
  • Visual disturbances
  • Convulsions
Precautions & warnings
  • Risk-benefit consideration in first trimester of pregnancy
  • Caution during breastfeeding
  • Caution in renal or hepatic impairment
  • Caution while driving
  • Avoid alcohol
Contraindications
  • Hypersensitivity
  • History of convulsive disorders
  • Porphyria
  • Infants <3 months
  • Severe renal impairment
Drug interactions
  • Reduced absorption with sucralfate and divalent/trivalent cations (aluminium, calcium, iron, magnesium, zinc)
  • Reduced excretion and increased plasma concentrations with probenecid
  • Reduced effects with chloramphenicol, nitrofurantoin, tetracycline
  • Fatal hemorrhagic enterocolitis with high-dose melphalan
  • May increase effects of warfarin
Food interactions

Alcohol may cause excessive drowsiness.

Use in pregnancy

Use in Pregnancy: Nalidixic Acid may be unsafe during pregnancy (Category C); animal studies show evidence of fetal harm.

Pregnancy Category: C — always consult a doctor before taking during pregnancy.

Use in lactation

Use in Lactation: Nalidixic Acid is safe during breastfeeding; not significantly excreted in breast milk.

Pediatric use

Contraindicated in infants <3 months; dose established for >3 months.

Geriatric use

Elderly may require dose adjustment.

Renal / hepatic impairment

Renal Impairment: Caution in kidney disease; dose reduction may be needed; monitor kidney function regularly.

Hepatic Impairment: Caution in liver disease; dose reduction may be needed; monitor liver function regularly.

Overdose effects

Overdose: Severe bloody diarrhea; symptomatic treatment.

Storage conditions

Store below 30°C; protect from light & moisture; keep out of reach of children.

Chemical structure

Nalidixic Acid

Common questions

What does Nalidixic Acid do?
It is used for urinary tract infections and shigellosis.
How to use it?
Take on empty stomach as prescribed by your doctor.
What are the side effects?
Nausea, diarrhea, allergy, convulsions, etc. may occur.
⚠️ This information is for educational purposes only — not a substitute for medical advice. Consult a registered physician before taking any medicine.