Antihypertensive Drug Adherence Remains Problematic

A new study suggests that over a third of people on blood pressure lowering drugs do not take their medication correctly, if at all.

Researchers at Charles University, Manchester Academic Health Science Centre, and other institutions conducted a study of urine and serum samples from 1,348 patients with hypertension, using liquid chromatography-tandem mass spectrometry. The researchers aim was to detect patient nonadherence to prescribed antihypertensive drugs, and to explore the association between non-adherence and demographic- and therapy-related factors.

The results showed that the rates of nonadherence to antihypertensive treatment were 41.6% in the United Kingdom and 31.5% in the Czech Republic. Nonadherence was inversely related to age and male sex. In addition, each increase in the number of antihypertensive medications led to 85% and 77% increase in nonadherence in the UK and Czech populations, respectively. The odds of nonadherence to diuretics were the highest among five classes of antihypertensive medications. The study was published on May 1, 2017, in Hypertension.

“We suspected that some patients haven't been taking their medications on a regular basis, but this analysis shows how high that figure is,” said senior author Professor Maciej Tomaszewski, MD, of MAHSC. “Clearly, the more blood pressure lowering drugs are prescribed, the higher the risk that the patients will not be taking them on a regular basis. We also showed that diuretics are particularly poorly taken.”

Estimates by the World Health Organization indicate that only about 50% of patients in developed countries follow treatment recommendations. Major barriers to compliance include the complexity of modern medication regimens, poor "health literacy" and lack of comprehension of treatment benefits, undiscussed side effects, the cost of prescription medicine, and poor communication or lack of trust between patient and health-care provider.