Ciprofloxacin, a fluoroquinolone antibiotic, targets bacterial DNA gyrase and topoisomerase IV. These enzymes are crucial for bacterial DNA replication, repair, and transcription. By inhibiting these enzymes, ciprofloxacin prevents bacterial growth and ultimately leads to bacterial cell death.
Excretion is primarily renal. About 40-50% of an oral dose is excreted unchanged in the urine within 12 hours. This percentage increases with higher urine pH. Here’s a breakdown:
- Renal Excretion: The major route, with glomerular filtration and tubular secretion playing key roles. This means that kidney function directly influences ciprofloxacin elimination. Metabolic Excretion: A smaller amount undergoes metabolism, primarily in the liver, producing inactive metabolites. These metabolites are also excreted via the kidneys.
Factors affecting excretion include:
Kidney function: Reduced kidney function significantly prolongs ciprofloxacin’s half-life, increasing the risk of adverse effects. Age: Elderly patients often have reduced kidney function, necessitating dose adjustments. Liver function: While minor, liver impairment may affect metabolism and subsequently excretion. Concurrent medications: Some drugs can interact, potentially altering ciprofloxacin’s clearance.
Monitoring kidney function, particularly creatinine clearance, is vital, especially in patients with pre-existing renal issues or those receiving high doses. Dosage adjustments may be necessary to prevent accumulation and toxicity. Always consult prescribing information for specific recommendations based on individual patient characteristics.
