Alendronate ( Fosamax ) reduces the ability of Teriparatide ( Forteo / Forsteo ) to increase bone mineral density ( BMD ) in osteoporotic men.

Researchers have evaluated whether Teriparatide increases osteoblast activity when the ability of Teriparatide to increase osteoclast activity is suppressed by Alendronate.

The study included 63 men, age 46–85, with low spine and/or hip bone mineral density.

Subjects received Alendronate 10 mg daily ( group 1 ), Teriparatide 37 microg sc daily ( group 2 ), or both ( group 3 ) for 30 months. Teriparatide was begun at month 6.

The primary endpoint was the change in serum N-telopeptide, osteocalcin, and amino-terminal propeptide of type 1 procollagen.

In men receiving Teriparatide monotherapy ( group 2 ), levels of all bone turnover markers increased markedly during the first 6 months of Teriparatide administration and then declined toward baseline during the next 18 months.

In men who received combination therapy ( group 3 ), bone turnover marker levels declined in the first 6 months ( while receiving Alendronate alone ) and then returned to baseline levels ( N-telopeptide ) or above ( osteocalcin and amino-terminal propeptide of type 1 procollagen ) after Teriparatide was added.

As with bone mineral density, Alendronate impairs the action of Teriparatide to increase bone turnover in men.

Teriparatide was approved in December 2002 by the FDA ( Food and Drug Administration ) for the treatment of osteoporosis in postmenopausal women who are at high risk for having a fracture. The drug is also approved to increase bone mass in men with primary or hypogonadal osteoporosis who are at high risk for fracture.

An estimated 10 million Americans - 80 percent of them women - suffer from osteoporosis, a progressive thinning of bones that may lead to an increased risk of spine, wrist, and hip fractures.

Teriparatide is the first approved agent for the treatment of osteoporosis that stimulates new bone formation. Teriparatide is administered by injection once a day in the thigh or abdomen. The recommended dose is 20 mcg per day.

Teriparatide is a portion of human parathyroid hormone ( PTH ), which is the primary regulator of calcium and phosphate metabolism in bones. Daily injections of Teriparatide stimulate new bone formation leading to increased bone mineral density.

In animal studies with Teriparatide, there was an increase in the number of rats developing osteosarcoma, a rare but serious cancer of the bone. The possibility that humans treated with Teriparatide may face an increased risk of developing this cancer cannot be ruled out.

Most side effects reported in association with Teriparatide in clinical trials were mild and included nausea, dizziness, and leg cramps. During the clinical trials, early discontinuation due to adverse events occurred in 5.6% of patients assigned to placebo and 7.1% of patients taking Teriparatide.

Persons with hypercalcemia, women who are pregnant or nursing, or persons who have ever been diagnosed with bone cancer or other cancers that have spread to the bones, should not use Teriparatide.

Source:

1) Journal of Clinical Endocrinology and Metabolism, 2006

2) FDA, 2002


XagenaMedicine2006



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