OSTEOPOROSIS IS characterized by low bone mass and skeletal fragility, leading to an increased risk of fracture. The diagnosis
is traditionally established by bone densitometry. The World Health Organization defines normal bone mineral density for women
as a value within one standard deviation of the young adult mean. Patients with values 2.5 standard deviations or more below
the mean have osteoporosis.
To decrease the risk of osteoporosis, patients of both genders and all ages should engage in regular exercise and maintain
an adequate intake of calcium and vitamin D. Vitamin D is needed for optimal absorption of calcium. The National Osteoporosis
Foundation recommends a daily intake of 400 to 800 IU of vitamin D for adults younger than 50 years, and 800 to 1000 IU of
vitamin D for adults who are older than 50 years.
"When serum concentrations of vitamin D are measured, levels greater than 30 ng/mL may be optimal, while levels below 20 ng/mL
are generally considered deficient," says Mark Abramowicz, MD, editor-in-chief of The Medical Letter on Drugs and Therapeutics, a non-profit newsletter that critically appraises drugs. "Some patients may require more than the recommended daily intake
of vitamin D to achieve appropriate blood levels."
A group of medicines called bisphosphonates decreases bone resorption by binding to active sites of bone remodeling and inhibiting
the cells that break down bony tissue. This group includes Fosamax (alendronate), Boniva (ibandronate), and Actonel (risedronate).
They may be taken daily or weekly, and Boniva and Actonel are available as once-a-month pills. Fosamax is the only generic
bisphosphonate available in the United States. "The bisphosphonates have been shown to be effective in preventing fractures in postmenopausal women with osteoporosis, and
they all appear to be relatively safe," says Dr. Abramowicz. "Weekly or monthly dosing have been at least as effective as
daily doses in increasing bone mineral density and are probably better tolerated."
Bisphosphonates can cause heartburn, esophageal irritation, abdominal pain and other gastrointestinal effects. To ensure proper
absorption, they must be taken after an overnight fast, in an upright position, and then the patient must remain upright for
30 minutes. In some cases there have been adverse gastrointestinal effects even when patients followed these instructions.
Reclast (zoledronic acid) was the first bisphosphonate approved by the FDA for once-yearly intravenous treatment of osteoporosis
in postmenopausal women. Boniva is approved for intravenous treatment once every three months. These IV bisphosphonates are
effective alternatives to oral forms.
PARATHYROID HORMONE INJECTIONS
Some drugs for osteoporosis
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The bisphosphonates act by decreasing bone turnover, while low-dose, intermittent subcutaneous injections of parathyroid hormone
act in a different mode. These injections increase bone density by stimulating bone formation. Forteo (teriparatide), a form
of parathyroid hormone, has been approved by the FDA for osteoporosis treatment for up to two years in both men and postmenopausal
women at high risk for fractures.
"This type of medication is usually reserved for people who are at high risk of a fracture and who cannot take a bisphosphonate,"
says clinical pharmacist Heather Webster, PharmD, who manages quality programs for WellPoint's Part D business. "This is typically
not a first-line treatment."
VITAMIN D OFFERS BENEFITS
Evercare, which operates special needs plans for United Healthcare, doesn't have a program that focuses exclusively on osteoporosis,
but does include targeted services for osteoporosis.
"Generally the people enrolled in special needs plans have a high burden of multiple chronic illnesses. Many have had falls
and fractures, and in this age group, a hip fracture can have catastrophic effects," says John R. Mach Jr., MD, a geriatrician
who serves as Evercare's board chair.
To prevent falls, Evercare makes a special effort to ensure these patients receive appropriate levels of vitamin D, since
studies have shown that vitamin D replacement actually reduces the incidence of falls.
"We're paying close attention to the newer studies on vitamin D," Dr. Mach says. "In our special needs population we screen
for vitamin D deficiency using a lab test. Then we get them on a fairly high replacement dose for a period of time, until
their vitamin D blood levels go back up. Then we put them on a maintenance dose. Paying attention to vitamin D levels is a
relatively easy thing to do, and it can prevent a catastrophic event."
Elaine Zablocki has been reporting on healthcare for more than a dozen years.
This article is based on information supplied by The Medical Letter ( http://www.medicalletter.org/),
a non-profit organization that publishes newsletters offering critical appraisals of new drugs and comparative reviews of
older drugs. The Medical Letter is completely independent of the pharmaceutical industry. It is supported entirely by subscription
sales and accepts no advertising, grants or donations. Institutional site license inquiries can be sent to info@medicalletter.org
.
Posted 2009-05-13 16:36:08.0
