CILOXAN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CILOXAN (CILOXAN).
Ciprofloxacin, a fluoroquinolone antibiotic, inhibits bacterial DNA gyrase and topoisomerase IV, blocking DNA replication and transcription.
| Metabolism | Ciprofloxacin is partially metabolized in the liver via CYP1A2, producing four metabolites: desethyleneciprofloxacin (M1), sulfociprofloxacin (M2), oxociprofloxacin (M3), and formylciprofloxacin (M4). |
| Excretion | Renal: 50-70% unchanged drug; biliary: 15-20% as metabolites; fecal: 20-35% |
| Half-life | Terminal elimination half-life approximately 4 hours in patients with normal renal function; extended to 8-12 hours in moderate renal impairment (CrCl 30-50 mL/min) and up to 24 hours in severe impairment (CrCl <30 mL/min) |
| Protein binding | 20-40% bound to serum proteins, primarily albumin |
| Volume of Distribution | 1.5-2.5 L/kg, indicating extensive tissue penetration |
| Bioavailability | Ophthalmic: negligible systemic absorption (<5% of applied dose); oral: not applicable (ophthalmic use only) |
| Onset of Action | Ophthalmic solution: within 15-30 minutes for bacterial conjunctivitis; ophthalmic ointment: within 1-2 hours |
| Duration of Action | Ophthalmic solution: 6-8 hours post-instillation; ophthalmic ointment: 8-12 hours; clinical effect sustained with q.i.d. dosing |
| Molecular Weight | 331.34 |
1-2 drops in affected eye(s) every 2 hours while awake for 2 days, then every 4 hours for 5 days; or 1-2 drops 4 times daily for 7 days. Ointment: ½-inch ribbon into conjunctival sac 3 times daily for 2 days, then 2 times daily for 5 days.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | No dosage adjustment required for ophthalmic use; systemic absorption is minimal. |
| Liver impairment | No dosage adjustment required for ophthalmic use; systemic absorption is minimal. |
| Pediatric use | Children ≥1 year: Same as adult dosing. Infants <1 year: Safety and efficacy not established. |
| Geriatric use | No specific adjustment; use same dosing as general adult population. |
| 1st trimester | Avoid; based on animal studies and no adequate human studies, potential risk to fetus outweighs benefits. Fluoroquinolones are associated with arthropathy in juvenile animals. |
| 2nd trimester | Avoid; due to limited safety data and potential for fetal harm, use only if clearly needed and benefit justifies risk. |
| 3rd trimester | Avoid; near term, potential for adverse effects on fetal bone and cartilage development. |
Clinical note
Comprehensive clinical and safety monograph for CILOXAN (CILOXAN).
| Placental transfer | Ciprofloxacin crosses the placenta after systemic administration, but ophthalmic absorption is minimal; however, significant transfer is not expected with topical ophthalmic use. |
| Breastfeeding | Ciloxan (ciprofloxacin ophthalmic) is excreted into breast milk in small amounts after systemic use. However, ophthalmic administration results in negligible systemic absorption. Caution is advised; monitor infant for possible gastrointestinal effects. |
■ FDA Black Box Warning
Fluoroquinolones, including ciprofloxacin, may exacerbate muscle weakness in persons with myasthenia gravis. Avoid use in patients with a history of myasthenia gravis.
| Serious Effects |
Hypersensitivity to ciprofloxacin or any quinoloneHistory of tendon disorders from fluoroquinolone use
| Precautions | Prolonged use may result in overgrowth of nonsusceptible organisms including fungi. Hypersensitivity reactions may occur. Use with caution in patients with corneal epithelial defects due to risk of corneal perforation. Discontinue if rash or allergic reaction occurs. |
| Food/Dietary | No significant food interactions for ophthalmic ciprofloxacin. Systemic absorption is minimal, so dietary restrictions are not necessary. |
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| Lactation Rating | L2 - Safer (limited data, but considered compatible with breastfeeding for ophthalmic use) |
| Teratogenic Risk | CILOXAN (ciprofloxacin) is contraindicated in pregnancy. Animal studies show arthropathy in immature animals; human data insufficient but fluoroquinolones may cause cartilage damage in neonates. Avoid in all trimesters unless no alternative. |
| Fetal Monitoring | Monitor for maternal gastrointestinal disturbances, CNS effects, and tendonitis. Fetal monitoring not specific; avoid use in pregnancy. |
| Fertility Effects | No specific human fertility data. Animal studies indicate no adverse effects on fertility. |
| Clinical Pearls | Ciloxan (ciprofloxacin ophthalmic) is a fluoroquinolone antibiotic used for bacterial conjunctivitis and corneal ulcers. Avoid use in patients with known hypersensitivity to fluoroquinolones. Prolonged use may lead to fungal or bacterial overgrowth. Not for injection; for ophthalmic use only. Contact lenses should be removed before instillation and may be reinserted 15 minutes after administration. In corneal ulcers, dosing is intensive (e.g., every 15 minutes for first 6 hours). |
| Patient Advice | Wash hands before use. · Do not touch the dropper tip to any surface. · Remove contact lenses before instillation; wait at least 15 minutes before reinserting. · Do not wear contact lenses during treatment for conjunctivitis. · Instill the prescribed number of drops into the affected eye(s). · Close the eye gently and press on the tear duct for 1 minute after instillation to reduce systemic absorption. · Complete the full course even if symptoms improve. · Report any signs of allergic reaction (rash, itching, swelling) or worsening symptoms. · Avoid sharing towels or washcloths to prevent spreading infection. · Store at room temperature, away from light and moisture. |