Osteoporosis affects nearly 200 million women worldwide — approximately one-tenth of women aged 60, one-fifth of women aged 70, two-fifths of women aged 80, and two-thirds of women aged 90.

The prevalence of bone diseases is expected to increase significantly as the population ages. In the U.S., the number of people age 65 and older is expected to rise to 86 million in 2050 from 35 million in 2000, while the number age 85 and older will increase from 4 to 20 million.

Fractures, which are common and can be quite debilitating, are by far the biggest problem caused by bone disease and are often the first sign of the disease in patients. Worldwide, osteoporosis causes more than 8.9 million fractures annually, resulting in an osteoporotic fracture every three seconds.

Treatment of osteoporosis should always include a well-balanced diet, the right amounts of calcium and vitamin D, daily exercise, not smoking, limited alcohol consumption, and safety precautions to prevent falls.

However, these important lifestyle changes are often not enough, and bisphosphonates (BPs), such as alendronate and risedronate, may be prescribed to stop further bone loss and prevent broken bones.

However, as with all medications, there is always the risk of side effects, and in a minority of patients, BP reactions can include flu-like symptoms, fever, headache, and joint or muscle pain. There have been rare reports of osteonecrosis of the jaw with BP medicines as well as reports of unusual fractures of the upper femur in those taking BP medicines for longer periods of time, for example, longer than five years.

These unusual fractures are different than the type of fractures that happen from untreated osteoporosis or atypical femoral fractures. Consequently, patients who take osteoporosis drugs for long periods of time are often advised to temporarily discontinue the drugs (drug holidays) to prevent such rare, but serious side effects.

To reduce the risk of these side effects, the American Association of Clinical Endocrinologists and American College of Endocrinology recommends that women at moderate risk for osteoporosis take a drug holiday after five years of oral treatment and three years of intravenous BP treatment.

Women at higher risk for osteoporosis should take a drug holiday after 10 years of oral treatment and 6 years of intravenous BP treatment. However, there are no recommendations on how long drug holidays should last.

In a study designed to further characterize the increased fracture risk in patients taking drug holidays, a retrospective chart review was conducted of 401 patients with osteopenia or osteoporosis who began a BP drug holiday from 2004 to 2013.

Collected parameters included demographics, previous therapy, bone mineral density (BMD), bone turnover markers, parathyroid hormone, calcium and vitamin D status, and clinical reports of fractures. Sixty-two (15.4 percent) patients developed a fracture during follow-up. The yearly incidence of fractures ranged from 3.7 to 9.9 percent, peaking at 9.9 percent and 9.8 percent during years four and five, respectively.

The mean age of the fracture group was higher than the nonfracture group, though not significantly different (69.24 ± 12.26 years vs 66.42 ± 10.18 years). Compared to the nonfracture group, the fracture group had lower femoral neck BMD and T-scores at baseline.

According to Dr. Pauline Camacho, senior author of the study, patients who choose a drug holiday warrant close monitoring by assessing fracture risks and resuming treatment accordingly.