Abstract 13971: Termination Profiles of Commonly Prescribed Antihypertensive Agents: A Cohort Study among 223,287 Patients

Abstract

Purpose: Termination of antihypertensive agents in clinical practice is associated with suboptimal blood pressure control, adverse patient outcomes and substantial health service utilization. We studied the association between antihypertensive drug class and their termination in a large Chinese population.

Methods: Using a clinical dataset, all adult patients newly received at least one antihypertensive agent in Hong Kong from the calendar years 2001-2003 and 2005 were included, except those who died 180 days after the prescription. The rate of drug termination 180 days after their first prescription was evaluated, and the factors associated with medication termination were studied by binary logistic regression analyses. We controlled for patients’ age, sex, ability to pay, service settings, resident districts, systolic blood pressure and the antihypertensive drug class.

Results: From a total of 223,287 subjects, 23.0% terminated their medications within 180 days of their prescriptions. As compared to users of thiazide diuretics, patients prescribed angiotensin converting enzyme inhibitors (ACEIs) (adjusted odds ratio [aOR] 1.95, 95% C.I. 1.86-2.05), alpha-blockers (aOR 1.20, 95% C.I. 1.15-1.26), beta-blockers (aOR 1.18, 95% C.I. 1.15-1.21) were more likely to have their medication terminated. Users of calcium channel blockers (CCBs) were less likely to have their drugs terminated (aOR 0.50, 95% C.I. 0.48-0.53).

Conclusion: The lower likelihood of medication termination among users of CCB might highlight their better tolerability profiles and better efficacy as compared with other antihypertensive drug classes among ethnic Chinese patients. Future studies should evaluate the reasons of drug terrmination.