Levofloxacin (APO-Levofloxacin)

Product Information

• Name: APO-Levofloxacin
• Active Ingredient: Levofloxacin
• Strength: 250 mg, 500 mg, and 750 mg tablets
• Manufacturer: Apotex Inc.

Therapeutic Classification

• Class: Antibacterial Agent

Mechanism of Action

• Levofloxacin is a synthetic broad-spectrum antibacterial agent. It inhibits bacterial DNA gyrase and topoisomerase IV, which are essential for DNA replication, transcription, repair, and recombination.

Indications and Clinical Use

• Upper Respiratory Tract: Acute sinusitis.
• Lower Respiratory Tract: Acute bacterial exacerbations of chronic bronchitis, community-acquired pneumonia, and nosocomial pneumonia.
• Skin and Skin Structure: Uncomplicated and complicated skin and skin structure infections.
• Urinary Tract: Complicated and uncomplicated urinary tract infections, acute pyelonephritis, chronic bacterial prostatitis.

Dosage and Administration

• Dosage for Normal Renal Function:
  • Acute bacterial exacerbation of chronic bronchitis: 500 mg once daily for 7 days or 750 mg once daily for 5 days.
  • Community-acquired pneumonia: 500 mg once daily for 7-14 days or 750 mg once daily for 5 days.
  • Nosocomial pneumonia: 750 mg once daily for 7-14 days.
  • Skin and skin structure infections: 500 mg or 750 mg once daily for 7-14 days.
  • Urinary tract infections: 250 mg once daily for 3-10 days or 750 mg once daily for 5 days.
  • Chronic bacterial prostatitis: 500 mg once daily for 28 days.
• Dosage Adjustment for Renal Impairment: Dose adjustments are required for patients with creatinine clearance ≤ 80 mL/min.

Contraindications

• Hypersensitivity to levofloxacin or other quinolone antimicrobial agents.
• History of tendinitis or tendon rupture associated with quinolone use.

Warnings and Precautions

• Tendinitis and Tendon Rupture: Increased risk in older patients, those on corticosteroids, and transplant recipients.
• QT Prolongation: Risk of arrhythmias; avoid use in patients with risk factors for QT prolongation.
• Hypersensitivity Reactions: Serious and potentially fatal reactions may occur.
• CNS Effects: May cause seizures and other CNS effects; use with caution in patients with CNS disorders.
• Blood Glucose Disturbances: Monitor blood glucose levels, particularly in diabetic patients.
• Photosensitivity: Avoid excessive sunlight or UV exposure.
• Hepatotoxicity: Rare but severe cases reported.
• Peripheral Neuropathy: Discontinue if symptoms develop to prevent irreversible condition.
• Clostridium difficile-associated Disease: Consider diagnosis in patients with diarrhea following antibacterial use.

Adverse Effects

• Common: Nausea, headache, diarrhea, insomnia, dizziness, constipation.
• Serious: Tendon rupture, QT prolongation, hypersensitivity reactions, hepatotoxicity, peripheral neuropathy, CNS effects.

Drug Interactions

• Antacids, Sucralfate, Metal Cations, Multivitamins: Decrease absorption of levofloxacin.
• Antidiabetic Agents: Risk of blood glucose disturbances.
• Theophylline, NSAIDs, Warfarin, Cyclosporine: Potential for increased effects or adverse reactions.

Pharmacokinetics

• Absorption: Rapid and nearly complete with peak plasma concentrations within 1-2 hours. Absolute bioavailability is approximately 99%.
• Distribution: Widespread distribution into body tissues, including skin and lung tissues.
• Metabolism: Limited metabolism, primarily excreted as unchanged drug in urine.
• Excretion: Major route is renal, with a half-life of approximately 6-8 hours.

Special Populations

• Pediatrics: Safety and efficacy not established.
• Geriatrics: Dose adjustment based on renal function may be necessary.
• Pregnancy and Nursing: Use only if potential benefit justifies the risk; may be excreted in human milk.
• Renal Insufficiency: Dosage adjustment required.