Osteoporosis drugs’ time limit is being considered by the FDA amid concerns over unusual fractures and possible high cancer rates linked to the widely-prescribed medicines.
Two FDA advisory panels were jointly meeting on Friday over whether to recommend a "drug holiday,” Reuters reports.
They were also considering clarifying how long people should take a class of osteoporosis drugs known as bisphosphonates, saying use exceeding five years had no benefit.
The drugs include Merck & Co's Fosamax, Warner Chilcott's Actonel, Roche's Boniva and Novartis' Reclast.
Taken by post-menopausal women to prevent osteoporosis, drugmakers told the advisers that an interruption in treatment may leave patients vulnerable to more fractures, reports Reuters.
FDA staff said rare femur fractures appear to be associated with use of the drugs, and the risk of jaw bone death may increase the longer people take them orally.
But they said the evidence demonstrating an increased cancer risk was inconsistent.
Some 4.5 million Americans over the age of 55 filled prescriptions for bisphosphonates in 2009, Reuters reports.
The drugs are commonly taken for osteoporosis, a progressive bone-thinning condition that typically causes bone fractures in the hip, wrist or spine.
Boniva and Reclast are available as injections, while the other drugs are taken orally.
Earlier this year, the labels added a warning of atypical femur fractures and Reclast's label was changed to highlight a higher risk of kidney failure, reports Reuters.
Dr. Robert Adler, an invited speaker at the advisory meeting, is an endocrinology professor at the Virginia Commonwealth University.
He said, "I have to tell my patients that we have no magic bullet, that our drugs decrease the risk of fracture but we have nothing that eliminates fracture.”
"Despite rare side effects, those patients who take bisphosphonates have fewer fractures and lower mortality, and these findings need to be shared with our patients," he argued, Reuters reports.
The drugmakers in question emphasized that studies have not directly linked or explained the connection between their medicines and adverse side effects.
They took issue with the lack of data on the consequences of patients ceasing treatment and suggested "drug holiday" decisions are best done for each patient individually.
But Dr. Marcea Whitaker, an FDA medical officer from the reproductive and urologic drugs division, said, "In light of the risk-benefit challenges, the available data suggest that therapy can be safely discontinued without the loss of efficacy.”
"However, additional data are needed to further define an appropriate duration of drug cessation,” she added, Reuters reports.