CIPRO
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CIPRO (CIPRO).
Ciprofloxacin inhibits bacterial DNA gyrase and topoisomerase IV, preventing DNA replication and transcription, leading to bacterial cell death.
| Metabolism | Ciprofloxacin is metabolized in the liver via CYP1A2, producing 4 metabolites: desethylene ciprofloxacin (major), N-acetyl ciprofloxacin, oxo-ciprofloxacin, and formyl ciprofloxacin. Approximately 40-50% of the dose is excreted unchanged in urine via glomerular filtration and tubular secretion. |
| Excretion | Renal (50-70% unchanged via glomerular filtration and tubular secretion); biliary/fecal (15-20%, primarily as metabolites); small amount metabolized to 4 metabolites (oxo-, sulfo-, and desethylene-ciprofloxacin). |
| Half-life | Terminal elimination half-life: 3-5 hours (normal renal function), extended to 8-10 hours in mild-to-moderate renal impairment (CrCl 30-50 mL/min) and up to >10 hours in severe impairment (CrCl <30 mL/min); half-life in elderly may be 5-8 hours due to reduced clearance. |
| Protein binding | 20-40% bound to serum proteins (primarily albumin). |
| Volume of Distribution | 2.1-2.8 L/kg (extensive, indicating penetration into tissues; high concentrations in lung, prostate, bone, and urogenital tissues; crosses blood-brain barrier with inflamed meninges). |
| Bioavailability | Oral: 70-80% (range 50-85%); decreased by 25-30% with concurrent antacids or calcium, iron, zinc supplements. Intravenous: 100%. |
| Onset of Action | Oral: 30-90 minutes (peak serum concentration 1-2 hours). Intravenous: immediate (peak at end of infusion). Topical (ophthalmic/otic): within 15-30 minutes. |
| Duration of Action | Antibacterial effect persists for approximately 12 hours post-dose (based on serum levels above MIC for most susceptible organisms); recommended dosing interval is 12 hours. Prolonged in renal impairment. |
| Molecular Weight | 331.34 |
| Action Class | Quinolones/ Fluroquinolones |
| Brand Substitutes | Wocipflo 500mg Tablet, Strox 500mg Tablet, Ciprodac 500 Tablet, Alciflox 500mg Tablet, Cifran OD 500mg Tablet, Cyprine FC 250mg Tablet, Cyprine 250mg Tablet, Ciprokind 250mg Tablet, Floxip 250 Tablet, Ciprodac 250 Tablet |
Ciprofloxacin 500 mg PO q12h or 400 mg IV q12h for uncomplicated infections; 750 mg PO q12h or 400 mg IV q8h for severe/complicated infections.
| Dosage form | FOR SUSPENSION |
| Renal impairment | CrCl 30-50 mL/min: 250-500 mg PO q12h or 200-400 mg IV q12h; CrCl 5-29 mL/min: 250-500 mg PO q18h or 200-400 mg IV q18-24h; hemodialysis: 250-500 mg PO q24h post-dialysis or 200-400 mg IV q24h. |
| Liver impairment | No dose adjustment required for mild-moderate hepatic impairment (Child-Pugh A/B). Use with caution in severe impairment (Child-Pugh C) due to limited data; monitor for adverse effects. |
| Pediatric use | Complicated UTI/pyelonephritis: 10-20 mg/kg IV q8h (max 400 mg/dose) or 10-20 mg/kg PO q12h (max 750 mg/dose); inhalational anthrax: 15 mg/kg IV q12h (max 400 mg/dose) or 15 mg/kg PO q12h (max 500 mg/dose). |
| Geriatric use | Start at lower end of dosing range due to age-related renal decline; monitor renal function and adjust dose per renal adjustment; increased risk of tendonitis/tendon rupture and CNS effects (dizziness, confusion). |
| 1st trimester | Avoid use in first trimester unless no alternative; associated with arthropathy in animal studies; human data limited but potential risk of Achilles tendon rupture. |
| 2nd trimester | Use only if benefit outweighs risk; fluoroquinolones may cause cartilage damage in immature animals; human fetal risk considered low but not established. |
| 3rd trimester | Avoid near term; potential for infantile arthropathy and CNS effects; also may increase risk of neonatal hyperbilirubinemia via albumin displacement. |
Clinical note
Comprehensive clinical and safety monograph for CIPRO (CIPRO).
| Placental transfer | Ciprofloxacin crosses the placenta; fetal serum concentrations reach 20-50% of maternal serum levels; animal studies show no teratogenicity at therapeutic doses. |
| Breastfeeding | Ciprofloxacin is excreted into breast milk in small amounts; risk of infant gastrointestinal disturbance, candidiasis, and potential joint damage; use caution, especially in nursing infants less than 1 month old; alternative agents preferred. |
■ FDA Black Box Warning
Fluoroquinolones, including ciprofloxacin, are associated with an increased risk of tendinitis and tendon rupture in all ages. This risk is further increased in patients over 60 years of age, those taking corticosteroids, and those with kidney, heart, or lung transplants. Fluoroquinolones may exacerbate muscle weakness in persons with myasthenia gravis. Avoid in patients with a history of myasthenia gravis.
| Serious Effects |
Hypersensitivity to ciprofloxacin or any fluoroquinoloneConcurrent use with tizanidineHistory of tendon disorders related to fluoroquinolone useMyasthenia gravis (may exacerbate muscle weakness)
| Precautions | Tendinitis and tendon rupture (black box warning), Exacerbation of myasthenia gravis, CNS effects including seizures, dizziness, and confusion, Peripheral neuropathy, QT prolongation, Clostridium difficile-associated diarrhea, Photosensitivity, Hepatotoxicity, Renal impairment (dose adjustment required), Hypersensitivity reactions, Aortic aneurysm and dissection (rare) |
| Food/Dietary | Avoid dairy products (milk, yogurt) and calcium-fortified foods within 2 hours before and 6 hours after ciprofloxacin. Avoid caffeine or reduce intake; ciprofloxacin inhibits caffeine metabolism. Avoid alcohol as it may increase CNS side effects. Take with a full glass of water; avoid taking with iron, zinc, or calcium supplements. |
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| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Ciprofloxacin is contraindicated in pregnancy due to arthropathy risk in juvenile animals. First trimester: limited human data; animal studies show cartilage damage; avoid. Second/third trimesters: potential fetal cartilage toxicity; avoid use. |
| Fetal Monitoring | Monitor for maternal GI symptoms, CNS effects (dizziness, headache), tendon pain/swelling; fetal ultrasound if exposed due to theoretical cartilage risk; in neonates, monitor for diarrhea, rash, or feeding intolerance. |
| Fertility Effects | Ciprofloxacin does not impair fertility or reproductive function in animal studies. Human data limited; no evidence of adverse effects on fertility. |
| Clinical Pearls | Ciprofloxacin is a fluoroquinolone antibiotic with broad-spectrum activity. It should be avoided in patients under 18 years due to risk of arthropathy. Use cautiously in elderly, renal impairment (dose adjustment needed for CrCl <30 mL/min), and patients with history of tendon disorders. It is a strong CYP1A2 inhibitor; monitor theophylline, tizanidine, and caffeine levels. QT prolongation risk, especially with other QT-prolonging drugs. Avoid concurrent NSAIDs due to increased CNS stimulation risk. |
| Patient Advice | Take exactly as prescribed; avoid missing doses. · Finish the full course even if you feel better. · Drink plenty of fluids to prevent crystalluria. · Avoid taking with dairy products, calcium-fortified juices, or antacids containing magnesium, aluminum, or calcium; take 2 hours before or 6 hours after these. · Report tendon pain, swelling, or rupture especially in Achilles; discontinue and rest at first sign. · Avoid sun exposure; use sunscreen and protective clothing. · This drug may cause dizziness or lightheadedness; avoid driving until you know how it affects you. · Use effective contraception; may reduce efficacy of oral contraceptives. · Notify doctor if you experience watery or bloody diarrhea, seizures, or irregular heartbeat. |