Adults

Typical dose for most infections is 500 mg orally twice daily. Duration varies from 7 to 14 days depending on the infection.

Elderly

No specific dose adjustment is required based solely on age, but renal function should be assessed, and dosage adjusted if renal impairment is present.

Renal_impairment

Dosage must be adjusted based on creatinine clearance (CrCl). For CrCl 30-60 mL/min, 250-500 mg every 12 hours. For CrCl <30 mL/min, 250-500 mg every 18-24 hours.

Onset

Rapid, clinical improvement can be observed within hours to days depending on the infection type and severity.

Excretion

Primarily via urine (renal) as unchanged drug and metabolites; some excretion occurs via feces.

Half life

Approximately 3-5 hours in adults with normal renal function.

Absorption

Rapid and well-absorbed after oral administration. Bioavailability is approximately 70-80%. Peak plasma concentrations are reached within 1-2 hours.

Metabolism

Partially metabolized in the liver to four active metabolites, but the parent drug remains the predominant form in systemic circulation.

NSAIDs

May increase the risk of CNS stimulation and convulsive seizures.

Warfarin

Enhanced anticoagulant effect, increased risk of bleeding. Monitor INR/PT.

Tizanidine

Concurrent use contraindicated due to increased tizanidine plasma concentrations, leading to hypotension and sedation.

Theophylline

Increased plasma levels of theophylline, potentially leading to toxicity. Monitor theophylline levels.

Corticosteroids

Increased risk of tendinitis and tendon rupture.

Antacids (Mg/Al), Sucralfate, Didanosine, Iron/Zinc Supplements

Reduced absorption of ciprofloxacin. Administer ciprofloxacin at least 2 hours before or 6 hours after these agents.

QT-prolonging drugs (e.g., Class IA and III antiarrhythmics, tricyclic antidepressants)

Increased risk of QT prolongation and arrhythmia.