Oral Anticoagulant Drugs and the Risk of Osteoporosis: New Anticoagulants Better than Old?

Abstract

Several drugs have been associated with an increased risk of osteoporosis when used chronically. Coumarins (warfarin, acenocoumarol, phenprocoumon, and fluindione) are oral anticoagulants widely used for the prevention and treatment of arterial and venous thromboembolic diseases. These drugs are vitamin K antagonists that interfere with γ-carboxyglutamate formation, and consequently inhibit the carboxylation of glutamate residues of proteins that are synthesized in the bone. These effects on bone turnover and dietary restrictions in patients on anticoagulation are possible mechanisms inducing osteoporosis in coumarin users. However, conflicting evidence is available concerning the risk of osteoporosis and bone fractures in patients on treatment with these drugs. This risk is likely to be clinically relevant in long-term (more than 1 year) coumarin users. Novel direct oral anticoagulants, recently introduced in clinical practice, exert reduced interference on bone metabolism; however, limited in vitro and animal data are currently available, and their long-term effects will only become apparent in time.

Mind the (treatment) gap: a global perspective on current and future strategies for prevention of fragility fractures

“…Accordingly, key observations on the impact of each class on BMD and fracture risk are indicated in table 6, primarily in accordance with the findings of Panday et al in their 2014 review on medication-induced osteoporosis [81]. Recent literature reviews specific to each drug class are also cited to provide the reader with a source of more detailed current information [82][83][84][85][86][87][88][89][90][91]. A focus on three commonly used classes -glucocorticoids, androgen deprivation therapy and aromatase inhibitors -serves to illustrate the potential benefits of strategies to prevent osteoporosis induced by medicines.…”

Guidelines for the diagnosis, prevention and management of osteoporosis

“…Long-term use of unfractioned heparin increases fracture risk by 2.5% to 5%, whereas there are no data on low molecular weight heparin. There is controversy in the literature about the effect of warfarin on risk of osteoporosis and fractures (42,49). Some drug categories may interfere with the anti-fracture efficacy of bisphosphonates.…”

Association Between Dabigatran vs Warfarin and Risk of Osteoporotic Fractures Among Patients With Nonvalvular Atrial Fibrillation

“…25 In contrast, the mechanism of dabigatran is independent of vitamin K and theoretically does not interfere with bone metabolism. 24 Therefore, it is biologically plausible that dabigatran may be associated with a lower risk for osteoporotic fracture compared with warfarin.…”