CIPROFLOXACIN HYDROCHLORIDE
Clinical safety rating: caution
Chelates with divalent cations (antacids Ca2+ Fe2+) reducing absorption May enhance effects of warfarin Associated with tendonitis and tendon rupture.
Inhibits bacterial DNA gyrase and topoisomerase IV, thereby inhibiting DNA replication and transcription.
| Metabolism | Hepatic metabolism via CYP1A2; metabolites include oxociprofloxacin, desethyleneciprofloxacin, and sulfociprofloxacin. |
| Excretion | Renal: 50-70% unchanged drug; biliary/fecal: 15-25% (partly as metabolites). |
| Half-life | Terminal half-life 4 hours (3-5 h) in normal renal function; prolonged to 5-10 h in mild-to-moderate renal impairment and >10 h in severe impairment (CrCl <30 mL/min). |
| Protein binding | 20-40% bound primarily to serum albumin. |
| Volume of Distribution | 2-3 L/kg, indicating extensive tissue penetration (e.g., lung, kidney, bone, prostate). |
| Bioavailability | Oral: 70-80% (fasting); reduced ~10-15% with food (but still therapeutic); intravenous: 100%. |
| Onset of Action | Oral: 0.5-2 hours; Intravenous: within minutes. |
| Duration of Action | 12 hours for most susceptible organisms (based on MIC and PK/PD target AUC/MIC >125 for Gram-negative, >30-50 for Gram-positive). |
| Molecular Weight | 367.8 Da (for hydrochloride) |
500-750 mg orally every 12 hours; 400 mg intravenously every 8-12 hours.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-50 mL/min: 250-500 mg orally every 12 hours or 200-400 mg IV every 12 hours. CrCl 5-29 mL/min: 200-500 mg orally every 18-24 hours or 200-400 mg IV every 24 hours. Hemodialysis: same as CrCl 5-29 mL/min, give after dialysis. Peritoneal dialysis: 250-500 mg orally every 24 hours. |
| Liver impairment | No adjustment required for mild-moderate hepatic impairment. Severe (Child-Pugh C): no specific guidelines; monitor for adverse effects. |
| Pediatric use | For complicated UTI or pyelonephritis: 4-6 mg/kg IV every 8 hours (max 400 mg/dose) or 10-20 mg/kg orally every 12 hours (max 750 mg/dose); duration 10-21 days. For inhalational anthrax: 15 mg/kg IV every 12 hours (max 400 mg/dose) or 20 mg/kg orally every 12 hours (max 750 mg/dose). For other indications based on specific guidelines. |
| Geriatric use | No specific dose adjustment based solely on age; adjust for renal function as per renal adjustment guidelines. Monitor for adverse CNS effects, tendon rupture risk, and QT prolongation. |
| 1st trimester | Avoid; arthropathy risk in animal studies; limited human data. |
| 2nd trimester | Avoid; use only if benefit outweighs risk; potential cartilage damage. |
| 3rd trimester | Avoid; possible fetal harm; reserve for serious infections. |
Clinical note
Chelates with divalent cations (antacids Ca2+ Fe2+) reducing absorption May enhance effects of warfarin Associated with tendonitis and tendon rupture.
| FDA category | Animal |
| Placental transfer | Crosses placenta; fetal serum levels 50-70% of maternal. |
| Breastfeeding | Excreted into milk; avoid or temporarily discontinue breastfeeding due to potential arthropathy and GI disturbances in infant. |
■ 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 older patients usually over 60 years of age, in patients taking corticosteroid drugs, and in patients with kidney, heart, or lung transplants. Fluoroquinolones may exacerbate muscle weakness in persons with myasthenia gravis. Avoid use in patients with a history of myasthenia gravis.
| Common Effects | Nausea |
| Serious Effects |
Hypersensitivity to ciprofloxacin or any fluoroquinoloneConcurrent tizanidine administration
| Precautions | Tendon rupture and tendinitis, Peripheral neuropathy, Central nervous system effects including seizures and increased intracranial pressure, Exacerbation of myasthenia gravis, Hypersensitivity reactions, Photosensitivity, Clostridioides difficile-associated diarrhea, Prolongation of QT interval, Blood glucose disturbances, Renal impairment (dose adjustment required) |
Loading safety data…
| Lactation Rating | L4 - Hazardous |
| Teratogenic Risk | First trimester: Limited human data; animal studies show no evidence of teratogenicity but arthropathy reported in juvenile animals. Second trimester: No documented fetal harm in humans; theoretical risk of cartilage damage. Third trimester: Avoid due to potential fetal cartilage damage and arthropathy. |
| Fetal Monitoring | Monitor for maternal gastrointestinal disturbances, CNS effects (dizziness, headache), and tendinitis. Fetal monitoring includes ultrasound for joint abnormalities if used in third trimester; consider fetal echocardiography if prolonged use. |
| Fertility Effects | No significant adverse effects on fertility in animal studies. In humans, no data suggest impairment; however, ciprofloxacin may cause transient sperm DNA damage at high doses, but clinical relevance is unclear. |
| Food/Dietary |
| Avoid dairy products (milk, yogurt, cheese) and calcium-fortified juices within 2-4 hours of taking ciprofloxacin, as calcium can bind and reduce absorption. Caffeine intake may be increased due to reduced clearance; monitor caffeine effects. Grapefruit juice may alter absorption; consider avoiding. |
| Clinical Pearls | Ciprofloxacin exhibits concentration-dependent killing; target AUC24/MIC ratio ≥125 for Gram-negative bacteria. Avoid in myasthenia gravis due to risk of exacerbation. Monitor for tendonitis or tendon rupture, especially in patients >60 years, those on corticosteroids, or with renal impairment. Use with caution in epilepsy or history of CNS disorders. Adjust dose in creatinine clearance <30 mL/min. Potential for QT prolongation; avoid with other QT-prolonging drugs. Antacids, sucralfate, metal cations (iron, zinc, calcium, magnesium) reduce absorption; separate by 2-4 hours. |
| Patient Advice | Take exactly as prescribed; do not skip doses or stop early even if feeling better. · Swallow tablets whole; do not crush or chew. · Take ciprofloxacin at least 2 hours before or 6 hours after antacids, sucralfate, or products containing calcium, iron, magnesium, or zinc. · Drink plenty of fluids to prevent crystalluria. · Avoid excessive sun or tanning; use sunscreen and protective clothing as this drug increases sensitivity to sunlight. · Contact your healthcare provider immediately if you experience tendon pain, swelling, or rupture; muscle weakness; numbness or tingling; seizures; or rash. · Notify doctor of all medications you take, including over-the-counter and herbal supplements, to avoid interactions. · May cause dizziness or lightheadedness; avoid driving or operating machinery until you know how this drug affects you. |