Adherence Rates Still Lacking in Hypertensive Patients

One of 5 patients are non-adherent to antihypertensive medications, a new study finds.

Medication adherence is an ongoing concern among health care professionals in all disease states. When patients are not adherent or start skipping doses, it can lead to serious problems.

In a study published in Hypertension, investigators found that 1 of every 3 individuals with hypertension fail to take their medication as prescribed.

Nonadherence leads to poorer cardiovascular outcomes, and is thought to cost approximately $100 billion to the US health economy.

The investigators used high-performance liquid chromatography-tandem mass spectrometry of urine and serum to detect nonadherence to antihypertensive medications among 1348 patients with hypertension in the UK and Czech Republic.

The results of the study showed that 41.6% of individuals in the UK cohort were non-adherent to treatment and 31.5% in the Czech cohort.

Nonadherence was related to the number of prescribed medications. Each increase in the number of antihypertensive medications led to more than a 75% increase in nonadherence.

The odds were highest for diuretics. Nonadherence was inversely related to age and male sex.

“Given the high prevalence of nonadherence, we should assess patients, particularly those on multiple antihypertensive medications or those who do not have an expected response to treatment,” said co-lead author Dr Pankaj Gupta.

The lack of a clinically useful objective measure that indicates when patients are not taking their medications is one of the primary reasons for the lack of progress in improving adherence rates.

To fill this gap, the investigators developed the liquid chromatography-tandem mass spectrometry to assess for nonadherence to antihypertensive drugs in blood or urine.

“This is a simple, relatively inexpensive and a robust test,” said co-lead author Dr Prashanth Patel. “And it has anecdotally changed the management of hypertension in many centers who use the test.

The team has set up a National Center for Adherence Testing at University Hospitals of Leicester and receive samples from approximately 25 hypertension clinics across the UK.