Association between Antihypertensive Polypharmacy and Medication Adherence in Adult Hypertensive Patients

Abstract

The use of antihypertensive drugs in combination to achieve optimal blood pressure control is growing, especially in people with uncontrolled or hard-to-control high blood pressure. But, the more medications required, the more difficult treatment could become and it can have an effect on the patient's ability to follow the advice of a prescription plan. The purpose of study was to determine the association between the number of prescribed antihypertensive medications and medication adherence among adult patients with hypertension. An analytical cross sectional study was conducted in a hospital setting with 240 patients having hypertension, aged 30-70 years. Consecutive sampling was used to recruit the participants from the outpatient department. Patients were classified by antihypertensive treatment into three groups: monotherapy, two-drug therapy and three-or-more-drug therapy. Medical adherence was evaluated by the 8-item Morisky Medication Adherence Scale (MMAS-8) and data on duration of treatment, dosage frequency, blood pressure status, and comorbidities were collected. Appropriate descriptive and inferential statistical tests were used to examine the relationship between the burden of antihypertensive medication use and adherence. 78 (32.5%) were taking one antihypertensive drug, 91 (37.9%) two antihypertensive drugs and 71 (29.6%) three or more antihypertensive drugs. Medication adherence was good in 34.6% of patients on monotherapy, 28.6% on two-drug therapy and 19.7% on three or more drugs. Low adherence was more common in those with greater burden of antihypertensive medications. Patients taking more complicated antihypertensive regimens were less likely to be optimally adherent (p < 0.05) with the number of antihypertensive medications taken. The number of antihypertensive drugs was significantly linked to medication nonadherence in adult hypertension. Treatment regimen simplification (where clinically appropriate) and personalized adherence counseling and medication review can promote long-term adherence and facilitate optimal hypertension care.