LAUSR

Objective: There is scarce data on the use of oral agents to treat acute severe hypertension in children, despite being common practice for children with no or minimal symptoms. The aim of this study was to evaluate the safety and efficacy of isradipine in children with acute hypertensive episodes, following a hospital-wide change from nifedipine to isradipine as the preferred calcium channel blocker for acute severe hypertension. Design and method: We reviewed the first 10 inpatients to receive isradipine at the sole tertiary paediatric hospital in Western Australia from June 2021. Patient characteristics and blood pressure (BP) measurements (systolic, diastolic and mean arterial pressure (MAP)) at baseline and during the six hours following isradipine administration were extracted. Linear regression and Spearman rank correlation coefficient were used to examine the relationship between dose and BP reduction. Adverse events and requirement for additional antihypertensives were also recorded. Results: A total of 10 patients (median 7 years, interquartile range [IQR] 4–11 years, youngest 2 years) received 23 doses of isradipine for discrete episodes of acute severe hypertension. The median systolic BP and MAP at treatment initiation were 140 mmHg (IQR 132–148) and 111 mmHg (IQR 104–119), respectively. The median dose administered was 0.09 mg/kg/dose (IQR 0.06–0.09). The median reduction of systolic and diastolic blood pressure were 13% (IQR 9–20%) and 11% (IQR 2–28%), respectively. The MAP dropped by 13% (IQR 7 to 25%). BP reached treatment targets following 18 doses (78%). In the 5 cases requiring a further antihypertensive dose, 3 received clonidine, one a further dose of isradipine, and one their regular antihypertensive agent. The systolic BP and MAP fell by more than 25% following a total of 4 (17%) and 6 (26%) of doses, respectively. There was no relationship between dose and outcome over the narrow range of mg/kg/dose administered. No child had a BP drop of more than 50% or any adverse events recorded. Conclusions: Isradipine was a safe and effective treatment for acute severe hypertension among our initial cohort. Further data is being collected to expand the pharmacodynamic information available for isradipine use in children.