About nalidixic acid
Quinolone antibacterial
Used for
- Treatment of susceptible urinary tract infections.
Usual adult dose
Usually 1 g by mouth every 6 hours for 1–2 weeks; follow local prescribing guidance.
Usual dose in children
Usually 55 mg/kg/day by mouth in four divided doses; generally avoided in young children.
Common side effects
- Nausea, vomiting, or diarrhea
- Headache or dizziness
- Sensitivity to sunlight
- Rare seizures or serious allergic reactions
Important warnings
- Not suitable for viral infections.
- May cause seizures; risk is higher with seizure disorders or certain medicines.
- Can cause tendon or nerve problems, though these are uncommon.
- Use only for infections caused by susceptible bacteria.
Pregnancy
Safety is not well established; generally avoided during pregnancy unless a clinician considers it necessary.
Breastfeeding
Avoid during breastfeeding when possible; seek clinician guidance because safety information is limited.
Interactions
- Anticoagulants such as warfarin: may increase bleeding risk.
- Probenecid: may increase nalidixic acid levels.
- Nitrofurantoin: may reduce antibacterial effectiveness.
- Antacids containing magnesium or aluminum may reduce absorption.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.