(RxWiki News) When one medicine doesn't help postmenopausal women with osteoporosis, doctors might recommend another. But if the second doesn't strengthen bones, what happens then? Taking them together might do the trick.
A recently published study found that taking two osteoporosis medications together worked better to increase bone density in postmenopausal women over taking just one.
These findings suggest that a specific combination of medicines could be useful in treating osteoporosis patients who are at a higher risk for fractures, according to the researchers.
"Talk to your doctor about building strong bones."
Joy Tsai, MD, from the Department of Medicine in Endocrine Unit at Massachusetts General Hospital, led a team of researchers in investigating whether two osteoporosis medications worked better in combination than each did alone to increase bone-mineral density in postmenopausal women.
The study included 94 women with osteoporosis who were past menopause. They were recruited through mailings, referrals and advertisements to Massachusetts General Hospital and randomly assigned to one of three groups given a different combination of osteoporosis medications.
The first group received the medicine teriparatide (Forteo), the second received denosumab (Prolia) and the third was given both medications together over a 12-month period between September 2009 and January 2011.
Patients who were given teriparatide received the medicine daily while those given denosumab received the medicine once every six months.
The researchers measured participants' bone density at the start of the study and three, six and 12 months later.
After 12 months, bone density of the lower part of the spine increased more in the group given both medicines together compared to the groups given just one medicine, the researchers found.
Overall, bone density of the lower spine increased by 9.1 percent in patients given both medicines. At the same time, bone density only increased by 6.2 and 5.5 percent in patients given teriparatide and denosumab, respectively.
"One medication, teriparatide (Forteo), works in the opposite direction to actually promote the formation of new bone," said Jason Poquette, BPharm, RPh, a registered pharmacist and dailyRx Contributing Expert. "Until recently, the consensus was that the combination of both types of medications would add no further benefit. However, the study just released by MA General Hospital calls that thinking into question – showing a statistically significant increase in BMD when the antiresoptive drug denosumab was combined with teriparatide."
Further, the neck of the thighbone and total hipbone density increased by 4.2 and 4.9 percent, respectively, in patients who received both medicines.
In patients who received teriparatide, densities in those two areas increased by 0.8 and 0.7 percent, respectively, and 2.1 and 2.5 percent in patients given denosumab.
None of the participants developed hypocalcaemia, or low levels of calcium in the blood.
"These additive effects were, therefore, seen in sites of both trabecular and mixed cortical and trabecular bone," the researchers wrote in their report. "Moreover, the 12-month changes in femoral-neck and total-hip bone mass density in the combination-therapy group were greater than have been reported with approved therapies for postmenopausal osteoporosis."
The authors noted that they knew who was receiving which combination of medicines, though the doctors who measured patients' bone density did not.
The researchers also did not look at the long-term safety of the combined medications, nor did they look at patients' risk of getting fractures.
How women reacted to the medications did not differ whether they had fractures or not, the researchers said.
The study was published online May 14 in The Lancet.
The Harvard Clinical and Translational Science Center, the National Center for Research Resources, Eli Lilly and Amgen funded the study.
One of the authors is a consultant for Eli Lilly and another previously consulted for Amgen Inc. All authors have received funding from Amgen and Eli Lilly.