Comparative Pharmacology
Head-to-head clinical analysis: ACTONEL WITH CALCIUM COPACKAGED versus FOSAMAX PLUS D.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ACTONEL WITH CALCIUM COPACKAGED versus FOSAMAX PLUS D.
ACTONEL WITH CALCIUM (COPACKAGED) vs FOSAMAX PLUS D
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ACTONEL WITH CALCIUM (COPACKAGED) contains risedronate sodium, a bisphosphonate that inhibits osteoclast-mediated bone resorption by binding to hydroxyapatite crystals in bone and inhibiting farnesyl pyrophosphate synthase (FPPS), an enzyme in the mevalonate pathway. This leads to reduced bone turnover and increased bone mineral density. The calcium component is for supplementation to prevent hypocalcemia.
Alendronate, a bisphosphonate, inhibits osteoclast-mediated bone resorption by binding to hydroxyapatite and interfering with the mevalonate pathway, leading to osteoclast apoptosis. Cholecalciferol (vitamin D3) promotes intestinal calcium absorption and bone mineralization.
Actonel (risedronate) 35 mg orally once weekly, taken with 6-8 oz of plain water at least 30 minutes before breakfast. Calcium supplement (e.g., 1250 mg calcium carbonate) taken with food at a different time of day.
One tablet (alendronate 70 mg / cholecalciferol 2800 IU) orally once weekly.
None Documented
None Documented
Terminal elimination half-life of risedronate is approximately 20 hours for the 5 mg daily dose and 480 hours for the 35 mg weekly dose due to prolonged retention in bone; clinically, the drug accumulates in bone and is slowly released.
Alendronate: Terminal half-life in bone is estimated at 10+ years due to slow release from the skeleton. Cholecalciferol: Half-life of 25-hydroxyvitamin D is ~15 days.
Risedronate is eliminated primarily via renal excretion, with approximately 50% of an absorbed dose excreted unchanged in urine. Unabsorbed drug is eliminated in feces. Total clearance is about 100 mL/min.
Alendronate: ~50% excreted unchanged in urine; remainder is taken up by bone and slowly eliminated. No biliary or fecal excretion of intact drug. Cholecalciferol: ~50% excreted in bile via feces; less than 1% in urine.
Category C
Category C
Bisphosphonate and Calcium Supplement
Bisphosphonate