While lack of adherence to bisphosphonates is well-known, recent research1 presented at the 69th Annual Meeting of the American College of Rheumatology in San Diego, California, has shed new light on possible causes, including difficulties in following the prescribing instructions, frequency of dosing schedules, potential drug-drug interactions, and fear of addiction.
Among the most frequently cited problems affecting adherence included difficulty following the special instructions for taking bisphosphonates (46%), too frequent dosing (44%), and difficulty fitting treatment into daily routines (42%), according to the new research.
The study of more than 500 postmenopausal women also uncovered the personal beliefs about pharmacologic therapy that were likely to influence adherence. For example, 54% of women said they worried that the medication would stop working if taken regularly; 56% said they were worried they might become addicted to bisphosphonates; and 44% reported concerns about taking long-term medication. Expectations of treatment were also conservative, with only 46% of patients believing therapy would prevent fractures.
"Difficulties following special instruction and frequency of dosing only compounded the reluctance this population has with a long-term medication regimen they already question," says lead investigator Paul Thompson, MD, FRCP, a consulting rheumatologist at Poole Hospital NHS Trust in Poole, England, UK, and a visiting professor at Bournemouth University in Bournemouth, England. "Additionally, there is a concern about tolerance and addiction to bisphosphonates, coupled with only the most conservative expectations for benefit. These mental hurdles are going to have to be overcome to gain any increased level of compliance in bisphosphonate therapy."
The best way to overcome these hurdles according to Dr. Thompson is "education, education, education," he tells CIAOMed. "This [education] needs to come from a variety of sources, especially the managing physician and perhaps specialist nurses, pharmacists, simple information in packaging, Web site advice, and patient follow-up."
For the study, Dr. Thompson and colleagues conducted telephone interviews from May through July 2005 with 533 osteoporotic postmenopausal women over age 50 who were taking or had taken a bisphosphonate. At the time the study was conducted, only once-daily or once-weekly bisphosphonate formulations were available in the UK.
Two-thirds of the women were still taking their bisphosphonate at the time of the interview, the study found. Of the cohort, 42% had suffered an osteoporotic fracture, and 52% failed to take the medication according to the prescribed instructions. Nonadherence occurred with all bisphosphonates, with 19% of women taking less than the prescribed dosage. According to the survey, 77% of women expressed a preference for taking bisphosphonates monthly rather than daily or weekly.
Follow-up key with silent diseases
CIAOMed editorial board member Nancy E. Lane, MD, a director of the Aging Center and distinguished professor of medicine and rheumatology at the University of California at Davis Medical Center in Sacramento, California, concurs with Dr. Thompson that educating patients about how and why to take the medication should resolve these adherence issues.
"After a few months, check to see if the patient is still taking the medication and if they are having any problems with the medication that could be solved," she suggests. "Order a test after 3 months to demonstrate to the patient that the medication is working and reducing a bone turnover marker like NTX. Osteoporosis for most patients is a silent disease, so compliance with medication is not high, and patients need reminders and encouragement from healthcare providers."
Reference
- Thompson P, Cooper C, Carr C. Factors influencing adherence to bisphosphonates for osteoporosis. Presented at: 69th Annual Meeting of the American College of Rheumatology; November 12–17, 2005; San Diego, Calif. Abstract 625.