MedicalResearch.com: What are the main findings of the study?
Dr. Vongpatanasin: We found that more than 50% of patients with resistant hypertension were non-adherent to at least one drug prescribed by their primary care physicians for blood pressure control.
When we provided this information back to the patients, as part of care in our hypertension specialty clinic, we found that many patients report difficulty taking prescribed medications due to either associated side effects or cost of the medication. When we adjusted patient’s medications to fit their needs, BP levels were substantially improved during subsequent visits without increasing the number of medications.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Vongpatanasin: Yes, previous studies in the hypertension referral centers indicated that the prevalence of medication non-adherence is about 10%-20%. However, adherence was assessed by patient self-report or questionnaire, which may in fact underestimate the numbers.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Vongpatanasin: Non-adherence to medication is common in patients who appear to have resistant hypertension. Physicians caring for patients with resistant hypertension should be cognizant of the magnitude of the problem and maintain open communication with the patients to avoid factors that predispose to non-adherence, such as drug side effects or complex regimen with high co-payment.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Vongpatanasin: Therapeutic drug monitoring is a useful screening tool in clinical practice to uncover non- adherence in hypertension. This should be considered in patients with persistently elevated BP despite multiple medications. The cost effectiveness of therapeutic drug monitoring in improving adherence and BP in hypertensive patients in the primary care setting needs to be further tested in larger studies.