P1653Six-year trends in antihypertensive monotherapy: focus on blood pressure control and originals/generics ratio

Background: Hypertension monotherapy is considered to be effective in 10–20% of patients with mild or mild-to-moderate hypertension (HTN). However latest evidence suggest sometimes a dramatic difference in efficacy and even safety of different members of an antihypertensive drug (AD) class. Purpose: The main objective of this study was to describe trends in choice of antihypertensive monotherapy in terms of precise AD class member, originals/generics and impact on blood pressure control in adult hypertensive patients referred to specialized cardiology clinic during the six-year period. Methods: We extracted 13691 monotherapy data from 68276 electronic medical records of patients referred to specialized cardiology clinic due to uncontrolled or therapy-naive HTN during the period of January 2010 - December 2015. Descriptive statistics were used to estimate the means, linear regression was employed to determine the yearly trends. Results: Overall, ACE inhibitors (ACEi) and angiotensin II receptors antagonists (ARA) remained the most commonly used antihypertensive drug classes [4326 patients (31,6%) and 4504 patients (32,9%), respectively] without significant 6-year trends. Approximately 16.6% of hypertensive adults were taking beta-blockers (2273 patients) and 11,8% (1616 patients) calcium channel blockers (CCBs), the use of these classes remained relatively constant during the survey period. Interestingly, diuretics were the less commonly used drug class without significant changes during 6-year period (7,1%, 972 patients). Perindopril (41,6%) and Enalapril (20,7%) were the most commonly used ACEi during studied period. Among other classes the leaders were Metoprolol (57,%) and Bisoprolol (20.7%) for beta-blockers; Losartan (52,9%) and Valsartan (37,5%) for ARA; Amlodipine (88,5%) and Nifedipine (6,6%) for CCB and Indapamide (85,3%) and Hydrochlorotiazide (6,6%) for diuretics without significant six-year trends. Mean percentage of originals constituted 34%. However there was a significant trend toward increase in the proportion of generics (R2 = 0.68; p=0.04). Blood pressure control rate on monotherapy was approximately 31% during studied period without significant 6-year trends. However monotherapy with ACEi and ARA provided better blood pressure control up to 35% compared to 27% on diuretics. Generics and originals provided similar effect on blood pressure level.