About nalidixic acid
Quinolone antibacterial
Used for
- Treatment of susceptible bacterial urinary tract infections.
Usual adult dose
Usually 1 g by mouth every 6 hours for 1–2 weeks; dosing depends on infection and local guidance.
Usual dose in children
For children over 3 months: commonly 55 mg/kg/day by mouth in four divided doses; specialist guidance is needed.
Common side effects
- Nausea, vomiting, diarrhea, or stomach discomfort
- Headache, dizziness, or drowsiness
- Sun sensitivity or skin rash
- Rarely, seizures or serious allergic reactions
Important warnings
- Not suitable for viral infections; use only for susceptible bacteria.
- May cause seizures; avoid in people with seizure disorders when possible.
- Can cause tendon or joint problems, especially in children.
- Seek urgent care for severe allergic symptoms or unusual muscle weakness.
Pregnancy
Generally avoid, particularly during the first trimester, unless a clinician considers it necessary.
Breastfeeding
Use only after clinical review; an alternative may be preferred, especially for a newborn.
Interactions
- Anticoagulants such as warfarin: bleeding risk may increase.
- Theophylline or caffeine: levels or effects may increase.
- Probenecid may reduce urinary concentrations and treatment effectiveness.
- Iron, zinc, or antacids may reduce absorption; separate doses.
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 It may be incomplete or out of date.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.