A study published in the Archives of Internal Medicine, Feb. 14th, 2011, compared fracture risk-reduction of oral bisphosphonates, drugs like Fosamax (alendronate), Actonel (risedronate), Boniva (ibandronate), in two groups of older adults. One group consisted of those using proton pump inhibitors (PPI), drugs like: Prilosec (omperazole), Nexium (esomeprazole), Aciphex (rabeprazole), Protonix (pantoprazole), and the comparison group of those NOT taking a PPI. The relative risk reduction in the non-PPI group was 39%, which was of statistical significance. The relative risk reduction was 19% in the PPI-treatment group, which was not statistically significant. The authors concluded that PPIs attenuate the fracture risk-reduction benefits of bisphosphonates and consideration should be made to alter therapies in order to gain benefit from the bisphosphonates.
One can then ask the question about whether the PPI is still needed, since it is not uncommon that PPIs are used well beyond their needed time to benefit. However, it can be challenging to stop a PPI due to rebound hyperacidity when stopping the drug abruptly, thereby giving one the impression they still need the drug. A slow taper is warranted when trying to stop a PPI. If a PPI is needed, then perhaps there are other osteoporosis therapies that do not interact with PPIs. We have Reclast (zoledronic acid) that is given intravenously. But that seems like a drastic step to avoid a drug interaction. There is Prolia (denosumab), a monoclonal antibody that has very good fracture risk reduction data. It is a subcutaneous injection that is given twice a year and without the kidney issues that exist with Reclast.
The real benefit in knowing of this drug interaction is that users of the two drugs then know not to rely upon the bisphosphonate thereby leading the user and their physician to find an effective strategy to reduce fracture risk. This then segues into the conversation about fracture risk reduction in the old-old cohort, the 80 or 90-something group, which may be best achieved through fall prevention strategies.