Men's Osteoporosis Support GroupOnline video recommendation; atrial fibrillation and bisphosphonates; eptidomimetic Inhibitors of Cathepsin K; osteonecrosis of the jaws case report I want to recommend an online video by Dr. Lisa Bero from the UCSF Department of Pharmacy. It is an excellent source of information on how to interpret some of the statistics and claims in research that you read or listen to in media reports. This is particularly helpful regarding the relative risk reduction interpretation when comparing the active treatment to the placebo. And it has other helpful information making it a worthwhile video to watch. Int J Clin Pract. 2010 Mar 11. [Epub ahead of print]. Ibandronate does not increase risk of atrial fibrillation in analysis of pivotal clinical trials. Lewiecki EM and others. PMID: 20337751. This paper reports the analysis of 6830 patients treated with ibandronate and 1924 treated with placebo. There was no difference in atrial fibrillation as adverse events or serious adverse events for the treatment group when compared to placebo. The authors concluded: "In this pooled analysis of all four ibandronate pivotal trials, including analysis by ACE, all studied ibandronate regimens, including the licensed doses of 150 mg monthly oral and 3 mg quarterly i.v., were not associated with an increased incidence of atrial fibrillation." Calcif Tissue Int. 2010 Mar 23. [Epub ahead of print]. Risk of Atrial Fibrillation Associated with Use of Bisphosphonates and Other Drugs Against Osteoporosis: A Cohort Study. Vestergaard P and others. PMID: 20309678. This Danish study involved all users of bisphosphonates and other drugs to treat osteoporosis between 1996 and 2006 (n = 103,562). There was an initial 8% and 9% increase in atrial fibrillation risk for etidronate and alendronate, respectively when compared to controls. However, when users of these medications were controlled for chronic obstructive pulmonary disease (COPD) incidence, the increased risk was no longer significant. The authors noted: "In conclusion, oral bisphosphonates do not seem to be associated with an excess risk of atrial fibrillation. Any excess risk seen in prior studies may be due to confounding from COPD." Editor's comments. I have reported on the issue of atrial fibrillation risk in those taking bisphosphonates before, including this 2009 Update. More and more studies are showing no significant risk of atrial fibrillation in bisphosphonate users, so I think this potential problem is being eliminated unless future studies show different results. For now, this seems like a non-issue. Curr Top Med Chem. 2010 Mar 26. [Epub ahead of print]. Peptidomimetic Inhibitors of Cathepsin K. Black WC. PMID: 20337585. This study reports on cathepsin K (Cat K) as a possible drug to treat osteoporosis. One form of it is now in Phase III clinical trials, which would indicate it is not too far from receiving FDA approval to treat osteoporosis if all goes well. Two other forms are also at different phases of clinical trials. Note the Related Articles on the right if you want to read more about this. The medication apparently works via blocking an enzyme involved in Type I collagen degradation that occurs in bone resorption and can be given on a once-weekly dosing schedule. Editor's comments. With a cursory Google search I also discovered this full text article on this topic. Note this is a 1997 study where the authors note that, "Representative inhibitors have demonstrated antiresorptive activity both in vitro and in vivo and therefore are promising leads for therapeutic agents for the treatment of osteoporosis." Thirteen years later (and there were obviously other studies done before 1997), we are not yet out of Phase III clinical trials. Obviously it is a very lengthy process to test a promising new drug. Head Neck. 2010 Mar 22. [Epub ahead of print]. Successful treatment of advanced bisphosphonate-related osteonecrosis of the mandible with adjunctive teriparatide therapy. Lee JJ and others. PMID: 20310042. Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a rare but serious and difficult to treat complication for those taking bisphosphonates for osteoporosis treatment. This is a case report of a 78-year-old osteoporotic woman who developed osteonecrosis of the mandible after taking alendronate (Fosamax). The authors report they were able to get healing starting at one month after placing the patient on teriparatide (Forteo) therapy for a total of six months. They concluded: "Our case demonstrated that teriparatide can be an important adjuvant in the management of advanced BRONJ and should be considered prior to major resection with reconstruction. Its true value in the treatment of BRONJ for noncancer patients with osteoporosis warrants future studies" Editor's comments: There are several Updates on this site dedicated to this topic of BRONJ. Here is one 2008 Update that can lead you to several others. Or you can do a Freefind search of the site from this page using "ONJ" as the search term to see all the articles. It is hard to draw strong conclusions based upon a single case report, but this one is very interesting and suggests a potentially important treatment option for those with BRONJ. Teriparatide works by stimulating bone formation, whereas the bisphosphonates block bone resorption. It is felt that in BRONJ cases there is too much blocking of resorption, with an eventual complete shut down of bone formation, which leads to bone necrosis. Logically, if you stimulate more bone formation, as teriparatide does, you should expect to overcome the causal factor of the osteonecrosis. Let's hope this turns out to be an effective treatment and that we'll see more case reports in the future with this success.
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