AVELOX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AVELOX (AVELOX).
Moxifloxacin is a fluoroquinolone antibiotic that inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, thereby interfering with bacterial DNA replication, transcription, repair, and recombination.
| Metabolism | Moxifloxacin is metabolized via glucuronide and sulfate conjugation; approximately 45% excreted unchanged in urine, 20% in feces. No significant CYP450 metabolism. |
| Excretion | Renal (approximately 45-60% as unchanged drug and metabolites) and biliary/fecal (approximately 20-30% as unchanged drug and metabolites). Total recovery in urine and feces accounts for >96% of the dose. |
| Half-life | Terminal elimination half-life is approximately 12 hours (range 10-14 hours) in healthy adults, allowing once-daily dosing. May be prolonged in patients with renal impairment. |
| Protein binding | Approximately 50% bound to serum proteins, primarily albumin. |
| Volume of Distribution | Volume of distribution (Vd) is approximately 2.5 L/kg (range 2-3 L/kg), indicating extensive tissue penetration, including lung, sinus, and urinary tract tissues. |
| Bioavailability | Oral bioavailability is approximately 90%, allowing for intravenous to oral switch therapy with equivalent exposure. |
| Onset of Action | Oral: Peak plasma concentrations achieved 1-3 hours after dosing. Clinical response may be seen within 24-48 hours. Intravenous: Immediate, with peak concentrations at end of infusion. |
| Duration of Action | Duration of clinical effect supports once-daily dosing. Antibacterial activity persists for the dosing interval (24 hours) due to concentration-dependent killing. |
| Molecular Weight | 401.43 |
400 mg orally or intravenously once daily for 7 to 14 days depending on infection severity.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for GFR ≥30 mL/min. For GFR <30 mL/min or on hemodialysis: 400 mg every 48 hours. |
| Liver impairment | No dose adjustment required for Child-Pugh A or B. Not recommended in Child-Pugh C due to limited data. |
| Pediatric use | Not approved for use in pediatric patients (age <18 years) due to risk of musculoskeletal disorders. Contraindicated in children and adolescents. |
| Geriatric use | No dose adjustment based on age alone. Monitor renal function and consider potential increased risk of QT prolongation and tendon disorders. |
| 1st trimester | Contraindicated due to risk of arthropathy and cartilage damage in animal studies; avoid use unless no safer alternative. |
| 2nd trimester | Contraindicated due to potential fetal bone and cartilage toxicity; avoid use unless no safer alternative. |
| 3rd trimester | Contraindicated due to risk of fetal harm; avoid use unless no safer alternative. |
Clinical note
Comprehensive clinical and safety monograph for AVELOX (AVELOX).
| Placental transfer | Moxifloxacin crosses the placenta; limited human data, but animal studies show fetal toxicity. |
| Breastfeeding | Avelox (moxifloxacin) is excreted into human milk; potential for serious adverse reactions in nursing infants including joint damage and CNS effects. Discontinue breastfeeding or drug, considering importance of drug to mother. |
■ FDA Black Box Warning
Fluoroquinolones, including moxifloxacin, increase the risk of tendinitis and tendon rupture in all ages. This risk is further increased in patients older than 60 years, those taking corticosteroids, and patients with kidney, heart, or lung transplants. Fluoroquinolines may exacerbate muscle weakness in patients with myasthenia gravis. Avoid use in patients with known history of myasthenia gravis.
| Serious Effects |
Hypersensitivity to moxifloxacin or any quinoloneHistory of tendon disorders with fluoroquinolonesChildren under 18 years of agePregnancy
| Precautions | Tendinopathy and tendon rupture, Peripheral neuropathy, Central nervous system effects including seizures and increased intracranial pressure, Exacerbation of myasthenia gravis, QT prolongation (avoid in patients with known QTc prolongation, uncorrected hypokalemia, or bradycardia), Hypersensitivity reactions, Clostridium difficile-associated diarrhea, Photosensitivity/phototoxicity, Disruption of blood glucose regulation |
| Food/Dietary | Avoid calcium-fortified foods, dairy products (milk, yogurt, cheese), antacids containing aluminum or magnesium, iron supplements, and sucralfate. These can bind to moxifloxacin and reduce absorption. Separate intake by at least 4 hours. Caffeine and alcohol are not known to interact significantly. |
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| Lactation Rating |
| L5 - Contraindicated |
| Teratogenic Risk | Fluoroquinolones are associated with arthropathy in juvenile animals; human data limited. First trimester: avoid unless essential due to potential risk; second/third trimester: use only if no safer alternative due to theoretical fetal cartilage damage. |
| Fetal Monitoring | Monitor maternal liver function tests, renal function, and signs of tendonitis or dysglycemia. Fetal monitoring per standard obstetrical care; consider ultrasound if prolonged use. |
| Fertility Effects | No evidence of impaired fertility in animal studies; human data lacking. Moxifloxacin may affect sperm parameters transiently; clinical significance unknown. |
| Clinical Pearls | Avelox (moxifloxacin) is a fluoroquinolone antibiotic with enhanced activity against respiratory pathogens, including Streptococcus pneumoniae and atypical organisms. Use cautiously in patients with QTc prolongation, electrolyte disturbances, or those on antiarrhythmics. Avoid in patients with known aortic aneurysm or connective tissue disorders due to risk of aortic dissection. Monitor for signs of tendinitis or tendon rupture, especially in patients over 60, those on corticosteroids, or with renal impairment. Doses should be adjusted for renal function (CrCl <30 mL/min). |
| Patient Advice | Take exactly as prescribed; do not skip doses or stop early. · Finish the full course even if you feel better. · Avoid taking with dairy products, antacids, or iron supplements; separate by 4 hours. · Report any sudden tendon pain, swelling, or rupture immediately. · Avoid driving if you experience dizziness or vision changes. · Stay well hydrated; drink plenty of fluids. · Avoid excessive sun exposure; use sunscreen. · Inform your doctor of all medications, especially heart rhythm drugs. · Do not take this medication if you have a history of tendon problems with fluoroquinolones. |