Adults

The usual adult oral dosage is 250 mg to 750 mg twice daily, depending on the type and severity of infection. For most common infections, 500 mg twice daily is recommended.

Elderly

Dosage should be adjusted based on renal function and the severity of the infection. Close monitoring is advised.

Renal_impairment

Dosage adjustment is necessary for patients with impaired renal function. The dose should be reduced based on creatinine clearance (e.g., if CrCl < 30 mL/min, 250-500 mg every 18-24 hours).

Onset

Within 1-2 hours of administration.

Excretion

Primarily excreted renally (about 50-70% as unchanged drug in urine), and to a lesser extent via the fecal route (about 15% as unchanged drug and metabolites).

Half life

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

Absorption

Rapidly and well absorbed from the gastrointestinal tract after oral administration, with an absolute bioavailability of about 70-80%. Peak serum concentrations are reached within 1-2 hours.

Metabolism

Partially metabolized in the liver (15-30%) to four active metabolites (desethyleneciprofloxacin, sulfociprofloxacin, oxociprofloxacin, and formylciprofloxacin), though these have less antimicrobial activity than the parent compound.

Caffeine

Decreased clearance of caffeine, leading to increased caffeine levels and potential adverse effects.

Warfarin

Increased anticoagulant effect, leading to a risk of bleeding. Monitor INR closely.

Tizanidine

Significantly increased tizanidine exposure, leading to severe hypotension and sedation. Concomitant use is contraindicated.

Theophylline

Increased plasma concentrations of theophylline, leading to increased risk of toxicity. Monitor theophylline levels.

Corticosteroids

Increased risk of tendinitis and tendon rupture.

Antacids, iron, zinc, sucralfate, didanosine

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