Mayo Clinic Proceedings Studies Analyze Osteoporosis Medication's Effects on Upper Gastrointestinal Tract Problems

Thursday, October 17, 2002

ROCHESTER, Minn. — In the October issue of Mayo Clinic Proceedings, researchers report that patients taking a common osteoporosis medication (bisphosphonate) showed no increase in upper gastrointestinal tract problems compared with groups taking placebos. The findings are important as physicians seek therapies to increase or maintain bone density in women with osteoporosis.

In a study that reviewed published material and abstracts related to adverse gastrointestinal events, researchers found that clinical reports of esophagitis associated with bisphosphonate use appear to have declined after proper administration of the medicine was explained to physicians following early reports of complications.

Bisphosphonates are effective for reducing the risk of both vertebral fractures and nonvertebral fractures, including hip fractures. The researchers said that early reports of esophagitis during bisphosphonate use were a result of capsules or pills becoming stuck in the esophagus or esophageal reflux. Since then, dosing instructions for oral bisphosphonates have been developed to minimize contact with the esophagus and ensure adequate absorption of the medicine into the body.

"The highest level of evidence comes from randomized controlled trials, and these data suggest that the risk of upper gastrointestinal tract problems can be minimized if bisphosphonates are administered properly," says Byron Cryer, M.D., University of Texas, Southwestern Medical School in Dallas, and principal author of the study.

Dr. Cryer notes that upper gastrointestinal tract events must be interpreted in the context of consequences of osteoporosis, which currently accounts for more than 250,000 hip fractures and a much higher number of other fractures each year in the United States. Upper gastrointestinal tract events appear to occur in fewer than one per 100 patients treated with bisphosphonates for three years, so the risk appears to be relatively low when compared with the benefits, Dr. Cryer says.

Dr. Cryer and Douglas Bauer, M.D., Department of Medicine, University of California–San Francisco, coauthored the study.

Another study in Mayo Clinic Proceedings also examined an oral bisphosphonate, alendronate. The findings of the randomized, double-blind, placebo-controlled study found the incidence of adverse gastrointestinal tract events was comparable between users of alendronate and placebos.

In this study, 11 percent of alendronate patients and 13 percent of the placebo patients reported an adverse upper gastrointestinal tract event. The 12-week multicenter study analyzed 450 postmenopausal women and men with osteoporosis. Patients treated with alendronate were on a once-a-week regimen.

Similar results were observed in subsets of patients with and without prior exposure to bisphosphonates, the researchers report.

"We conclude from this study that once-weekly alendronate, 70 mg, is a generally well-tolerated treatment option for patients with osteoporosis," says Joanne Palmisano, M.D., Merck & Co. Inc., clinical development and an author of the study.

And while the findings show that the frequency and types of upper gastrointestinal symptoms are not different compared with those experienced by patients taking placebos, physicians should remain cautious and weigh the benefits against the risks with each patient, write two Mayo Clinic physicians in the issue's editorial.

"The studies in this issue of the Mayo Clinic Proceedings show that bisphosphonates are safe for the gastrointestinal tract in patients viewed as a group, but physicians must be vigilant for the chance of adverse gastrointestinal effects in the individual patient," write William Tremaine, M.D., Division of Gastroenterology and Hepatology and Internal Medicine; and Sundeep Khosla, M.D., Division of Endocrinology, Diabetes, Metabolism, Nutrition and Internal Medicine, both of Mayo Clinic in Rochester.

Funding from Merck & Co. Inc. supported this study.

Mayo Clinic Proceedings is a peer-reviewed and indexed general internal medicine journal, published for more than 75 years by Mayo Foundation, with a circulation of 130,000 nationally and internationally.

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Contact:
John Murphy
507-284-5005 (days)
507-284-2511 (evenings)
e-mail: newsbureau@mayo.edu

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