PROQUIN XR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PROQUIN XR (PROQUIN XR).
Fluoroquinolone antibiotic that inhibits bacterial DNA gyrase and topoisomerase IV, preventing DNA replication and transcription.
| Metabolism | Hepatic metabolism via glucuronidation and sulfate conjugation; minor CYP450 involvement. |
| Excretion | Primarily renal excretion of unchanged drug (~60-80%) via glomerular filtration and tubular secretion. Biliary/fecal excretion accounts for approximately 20-35%, with a small portion as metabolites. |
| Half-life | Terminal elimination half-life is approximately 10-14 hours in patients with normal renal function (CrCl >80 mL/min). Extended half-life may occur in renal impairment, necessitating dose adjustment. |
| Protein binding | Approximately 30-40% bound to serum proteins (primarily albumin). Low protein binding minimizes displacement interactions. |
| Volume of Distribution | Volume of distribution is 1.7-2.5 L/kg, indicating extensive tissue penetration into lungs, prostate, and urinary tract tissues, exceeding plasma concentrations. |
| Bioavailability | Oral bioavailability is approximately 60-70% for the extended-release formulation, with food slightly increasing peak concentration (Cmax) but not overall AUC. |
| Onset of Action | Following oral administration of PROQUIN XR, therapeutic plasma concentrations are achieved within 1-2 hours. Peak concentrations occur around 6-8 hours due to extended-release formulation. |
| Duration of Action | Duration of antimicrobial activity is approximately 24 hours, allowing once-daily dosing. The extended-release design maintains effective plasma concentrations throughout the dosing interval. |
500 mg orally once daily with food.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | CrCl 30-50 mL/min: 500 mg every 48 hours; CrCl <30 mL/min: 500 mg every 72 hours; hemodialysis: 500 mg after each dialysis session. |
| Liver impairment | No dosage adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not studied in severe impairment (Child-Pugh C). |
| Pediatric use | Safety and efficacy not established in patients <18 years. |
| Geriatric use | Increased risk of QT prolongation and tendon rupture. Use lowest effective dose; monitor renal function and electrolytes. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PROQUIN XR (PROQUIN XR).
| Breastfeeding | PROQUIN XR (levofloxacin) is excreted into human milk in small amounts. M/P ratio is approximately 0.73 based on limited data. Manufacturer advises caution or temporary discontinuation due to potential adverse effects on infant joint cartilage. Consider risk-benefit; alternative agents preferred. |
| Teratogenic Risk | Fluoroquinolones including PROQUIN XR are generally avoided in pregnancy due to potential fetal cartilage damage observed in animal studies. First trimester risks include possible skeletal anomalies; second and third trimester risks involve arthropathy and possible CNS effects. Human data is limited but suggests no major malformation risk; however, use is not recommended due to safety concerns. |
■ FDA Black Box Warning
Fluoroquinolones, including PROQUIN XR, may exacerbate muscle weakness in persons with myasthenia gravis. Avoid use in patients with known history of myasthenia gravis.
| Serious Effects |
Known hypersensitivity to ciprofloxacin or other fluoroquinolones; concomitant use with tizanidine; history of myasthenia gravis.
| Precautions | Tendonitis and tendon rupture; peripheral neuropathy; CNS effects including seizures; Clostridium difficile-associated diarrhea; photosensitivity; QT prolongation; renal impairment dose adjustment. |
Loading safety data…
| Fetal Monitoring | Monitor maternal renal function and liver enzymes. Fetal monitoring includes ultrasound for skeletal development if exposure occurs. Watch for maternal adverse effects like tendonitis, QT prolongation, and C. difficile infection. Newborn monitoring for joint or neurological symptoms if exposed near term. |
| Fertility Effects | Fluoroquinolones including PROQUIN XR have no established effects on human fertility. Animal studies show no impairment at clinically relevant doses. No specific data on ovarian or testicular function. |