‘Vacation’ from osteoporosis treatment hinges on fracture risk

DEAR DR. ROACH: I read your article recently regarding weighing the risk of medication against the risk of not taking it. I recently was injected with Prolia (denosumab), and am scheduled again for one in December. I am 79 years old, 5 feet, 4 inches tall and weigh 108 pounds. I started Fosamax in 2007, and took 35 mg until several years ago, when the dose changed to 70 mg. My doctor is an endocrinologist, who treats thyroid conditions that I have. He suggested a five-year “vacation” from the Fosamax (alendronate) last year, then changed his mind, so I was on 70 mg all last year. This year he prescribed the Prolia injection.

My hip bones actually have increased in density in the past year (my T-score went from -1.8 to -1.6). I’m on my feet a lot, walk around 30 minutes per day at a fairly fast pace and do strengthening exercises on a large rubber ball daily. I take 400 mg daily of magnesium and take 1,100-1,200 mg calcium citrate per day (from food and supplements). I try to eat about 35-50 grams of protein daily. Do I need treatment for osteoporosis now? -- J.H.

ANSWER: I used the FRAX tool (https://www.shef.ac.uk/ FRAX/tool.jsp) to get an estimate of your risk for a hip fracture, and based on the information you gave me, the tool estimates a 2.9 percent chance of a hip fracture in the next 10 years. You have been on alendronate (Fosamax) and denosumab (Prolia) for almost 10 years. Even though you stopped taking the alendronate last year, the medicine stays in bones for a very long time (perhaps decades), and with very prolonged use, the risk of atypical femur fractures increases. This is because alendronate and other similar drugs, including teriparatide (Forteo), work by preventing bone turnover, leading to the possibility of stress fractures. Most experts recommend a reassessment of risk after five to seven years on these types of drugs.