Drug nonadherence is a common but often overlooked cause of hypertensive urgency and emergency at the emergency department.

OBJECTIVES: Over 70% of patients who visit the emergency department with a hypertensive emergency or a hypertensive urgency have previously been diagnosed with hypertension. Drug nonadherence is assumed to play an important role in development of hypertensive urgency and hypertensive emergency, but exact numbers are lacking. We aimed to retrospectively compare characteristics of patients with hypertensive urgency and hypertensive emergency and to prospectively quantify the attribution of drug nonadherence.
METHODS: We retrospectively analysed clinical data including information on nonadherence obtained by treating physicians of patients with SBP at least 180 mmHg and DBP at least 110 mmHg visiting the emergency department between 2012 and 2015. We prospectively studied drug adherence among patients admitted to the emergency department with severely elevated BP by measuring plasma drug levels using liquid chromatography tandem mass spectrometry from September 2016 to March 2017.
RESULTS: Of the 1163 patients retrospectively analysed, 257 (22.0%) met the criteria for hypertensive urgency and 356 (30.6%) for hypertensive emergency. Mean SBP (SD) was 203 (19) mmHg and mean DBP 121 (12) mmHg. Mean age was 60.1 (14.6) years; 55.1% were men. In 6.3% of patients with hypertensive urgency or hypertensive emergency, nonadherence was recorded as an attributing factor. Of the 59 patients prospectively analysed, 18 (30.5%) were nonadherent for at least one of the prescribed antihypertensive drugs.
CONCLUSION: Hypertensive urgency and hypertensive emergency are common health problems resulting in frequent emergency department admissions. Workup of patients with a hypertensive urgency or hypertensive emergency should include an assessment of drug adherence to optimize treatment strategy.