(RxWiki News) Some patients who worry about taking too much of a prescription medicine might not take their meds as prescribed, including arthritis patients. Not following the dose instructions has become a lot more common.
Only one in five rheumatoid arthritis patients among an economically disadvantaged and ethnically diverse population took their medicine as prescribed, a new study found.
These research findings showed that less than two-thirds of the prescribed disease-modifying antirheumatic drugs (DMARDs) dosages for joint inflammation were taken correctly.
"Questions about your medicine? Speak with a pharmacist."
Christian Waimann, MD, from the University of Texas MD Anderson Cancer Center in Houston, studied 107 patients with rheumatoid arthritis who agreed to have their oral medicine intake monitored electronically using the Medication Event Monitoring System over a two-year period.
Patients had rheumatoid arthritis about eight years on average. Almost two-thirds of the participants were Hispanic, 19 percent were African American, and 16 percent were white. And nearly 90 percent of the patients were female.
The medicines included DMARDs and prednisone. DMARDs suppress the immune system to prevent inflammation such as that caused by arthritis.
The patients were categorized into one of three groups based on whether they took their medicine as prescribed by their doctors on a day-to-day basis: doses taken as prescribed, underdosing and overdosing.
For patients who took methotrexate, the researchers tracked the number of weeks that patients complied. Methotrexate is the initial drug of choice, according to the researchers.
More than two-thirds of the patients received prednisone for their arthritis, and 57 percent were treated with a biologic medicine, including adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade).
Less than half the patients were prescribed one DMARD, 36 percent were prescribed two DMARDs, 15 percent were prescribed three DMARDs, and only four patients were prescribed four DMARDS.
Participants were surveyed on their disease activity and quality of life related to their arthritis.
Only 20 percent of the patients correctly took DMARDs at least 80 percent of the time, the researchers found.
In total, 70 percent of patients who took prednisone took the correct dosage. At the same time, less than two-thirds of patients took the correct dose of DMARDS.
Patients who were in better mental health with less depression and lower disease activity were statistically more likely to adhere to their medicines.
The researchers also found that patients who took their medicine as prescribed had significantly lower disease activity scores compared to patients who did not take their medicines as prescribed.
"Our findings should alert physicians about the need to integrate adherence assessments into daily practice, to explore potential barriers to non-adherence, and to engage in discussions with patients to highlight the importance of taking medications as prescribed to reach therapeutic target goals," the researchers wrote in their report.
The researchers noted their study only included patients who had rheumatoid arthritis less than 15 years, which excluded patients who had the condition for a longer period of time.
Their findings also did not show why patients did or did not adhere to their medication. With better adherence, the researchers said it would have improved patients' conditions.
The study, funded by a grant from the National Institute of Arthritis and Musculoskeletal and Skin Diseases under the National Institute of Health, will be published in the June 2013 issue of the journal Arthritis & Rheumatism by the American College of Rheumatology.