Prof John Eisman
The often-recommended de-prescribing or ‘drug holidays’ from anti-resorptive therapies are not advisable for many patients at risk of fragility fractures, according to osteoporosis experts.
A MJA editorial by Professor John Eisman and Associate Professor Christopher White said the benefit of bisphosphonates on bone might persist for 1-2 years beyond cessation of therapy but was variable.
They said temporarily ceasing therapy was ‘justifiable only for patients judged to be at low risk of fracture on the basis of clinical factors, the absence of recent fractures, and bone density above the osteoporosis range’.
While there were no guidelines about monitoring patients after ceasing bisphosphonate therapy, re-instituting therapy was appropriate if bone mineral density measurements or clinical characteristics suggested a subsequent increase in risk.
Their warning was even stronger for patients treated with monoclonal antibodies for fracture risk.
“A break in therapy is contraindicated for people receiving denosumab; the accumulated bone density benefit of even years of denosumab is lost within 6-12 months during the rapid decline after missing a dose.”
They added that denosumab should probably not even be started if there was a likely problem with long-term adherence.
The editorial also said the risk of potential side effects from anti-resorptive therapy had been exaggerated.
At less than one event per 10,000 person-years, the risk of adverse events such as osteonecrosis of the jaw (ONJ) and atypical femur fractures did not outweigh the likely benefit of treatment.
“In cases of chronic disease, specific treatments are withdrawn if they are ineffective, there is a better alternative, the condition is cured or in remission, the risk exceeds the benefit, or, after consulting the patient, a palliative approach is deemed more appropriate. These considerations rarely apply when treating people with osteoporosis.”
The editorial noted that most fractures occur in people whose bone mineral density was in the osteopenic rather than the osteoporotic range.