📋 Indications & Clinical Dosage
*Urinary tract infections:*
Adults: Acute infections; 1 gm four times daily for min 7 day. Chronic infections; 500 mg four times daily.
Children 3 months-12 yrs: 12.5 mg/kg 4 times daily for 7 days, reduced to 7.5 mg/kg 4 times daily in prolonged therapy or 15 mg/kg twice daily for prophylaxis; 12-18 yrs: 900 mg 4 times daily for 7 days, reduced in chronic infections to 600 mg 4 times daily.
*Gastro-intestinal infections due to gram-negative organisms:*
Adult: 500 mg-1 gm four times daily.
⛔ Contraindications
Acute porphyrias, avoid in risk factor for QT interval prolongation such as; acute myocardial infarction, bradycardia, congenital long QT syndrome, electrolyte disturbances, heart failure with reduced left ventricular ejection fraction and history of symptomatic arrhythmias,
⚠️ Precautions & Warnings
Caution in liver disease. Use with caution in renal impairment; avoid if eGFR less than 20 ml/minute/1.73m2,anaemia, diabetes mellitus, electrolyte imbalance, pulmonary disease; on long-term therapy, monitor liver function and monitor for pulmonary symptoms, especially in the elderly
🔄 Drug Interactions
Anticoagulants, probenecid, antibacterials, caution if concomitant use with other drugs known to prolong the QT interval.
⚠️ Adverse Reactions / Side Effects
Cranial nerve palsy, increased intracranial pressure, metabolic acidosis, peripheral neuropathy, toxic psychosis, GI, CNS and visual disturbances, rash-es, blood dyscrasias, convulsions, photosensitivity.
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
No evidence of risk in humans
Lactation / Breastfeeding:
Avoid. Risk to infant very small
📚 Official Regulatory & Clinical References
- Drug Regulatory Authority of Pakistan (DRAP): Drug Registration, S.R.O. Price Gazettes & National Essential Medicines List (NEML).
- World Health Organization (WHO): Collaborating Centre for Drug Statistics Methodology (ATC/DDD Index).
- Formulary Standards: British National Formulary (BNF) & Pakistan National Formulary (PNF) guidelines.