Drug Fights Medication-Linked Bone Loss

Drug Fights Medication-Linked Bone Loss
WEDNESDAY, Nov. 14 (HealthDay News) -- An osteoporosis drug has provensuperior to standard therapy at slowing bone loss caused by asthmatreatment, researchers say.
Glucocorticoid medicines such as prednisone are often given to treatasthma, autoimmune disorders, skin allergies and other conditions,researchers note. But the drugs can also cause osteoporosis.
The drug, an anabolic agent called teriparatide, probably will be thepreferable treatment "for patients who have particularly bad disease tostart with or are on glucocorticoids for a long time," said Dr. Kenneth G.Saag, professor of medicine and epidemiology at the University of Alabamaat Birmingham.
The study, which was funded by teriparatide's maker, Eli Lilly &Co., is published in the Nov. 15 issue of the New England Journal ofMedicine.
One million Americans are taking glucocorticoids for one condition oranother, Saag said, and many are at higher risk of fractures, because themedications weaken their bones. Current treatment for medication-linkedosteoporosis centers on use of bisphosphonates, medications designed toprevent bone breakdown.
The 18-month trial included 428 men and women with drug-causedosteoporosis who had been taking glucocorticoids for at least threemonths. Half were assigned to take alendronate, a bisphosphonate, whilethe other half took teriparatide.
After three months, the increase in bone density at the lumbar (lower)spine was double for those taking teriparatide -- an average 7.2 percentrise versus 3.4 percent in the alendronate group. The teriparatide groupalso experienced fewer fractures of the vertebral bones compared withthose on the bisphosphonate.
But teriparatide's much higher cost will limit its use, Saag said. "Useof therapy is driven by insurance as well as by appropriate bone densityand fracture rate," he said. "We would like to be able to single out thosepatients whose minimal bone density puts them at higher risk forfracture," Saag said. "Those patients are the ones we want to target moreaggressively."
That group would include 30 percent to 50 percent of those withdrug-caused osteoporosis, he said. The U.S. Food and Drug Administrationalready has approved use of teriparatide for the treatment of osteoporosisin postmenopausal women at high risk for fracture and to increase bonemass in men at high risk of fracture with primary or hypogonadalosteoporosis.
The anabolic agent is a better treatment, because bisphosphonates donot actually promote bone growth, added Dr. Robert R. Recker, professor ofmedicine at Creighton University and a member of the Osteoporosis ResearchCenter there. Rather, they prevent bone destruction by natural processessuch as apoptosis (natural cell death), he said
"There is a greater need for a bone-forming agent, one that interfereswith the apoptosis of bone cells," Recker said. "The condition is not somuch a low bone mass disease but a disease of bone cells that results intoo much remodeling. Bisphosphonates lower remodeling. [Teriparatide]increases new bone formation."
But longer-term studies are still needed to assess teriparatide'seffects over prolonged periods, Recker said.
"Not one study has gone long enough to see if you get more benefits byusing it for a long time," he said. "It may be good for 24 months. Thatremains to be seen."
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