SAN FRANCISCO — The first pediatric study of isradipine therapy for acute hypertension suggests that it effectively lowers blood pressure and that a lower starting dose may be appropriate for children younger than 2 years.
The retrospective, single-center, observational study looked at the effects of a first-time dose of isradipine in the hospital or emergency department to treat acute hypertension in 391 children over a 2-year period. Mean blood pressures fell significantly from 147/92 mm Hg before treatment to 122/69 mm Hg, reaching a nadir 2.7 hours after treatment, Dr. Yosuke Miyashita and associates reported in a poster presentation at the annual meeting of the American Society of Hypertension.
Treatment also decreased mean arterial pressure significantly from 110 mm Hg to 86 mm Hg, said Dr. Miyashita of the University of Washington, Seattle.
Mean arterial pressure decreased by a median 24% in the 34 patients (9%) aged younger than 2 years, by 22% in 127 patients (32%) aged 2–11 years, by 18% in 167 patients (43%) aged 12–16 years, and by 20% in 63 patients (16%) aged 17 years or older.
Greater than 25% declines in mean arterial pressure—and adverse effects—were significantly more likely with dosages of 0.09 mg/kg compared with dosages of 0.08 mg/kg or lower. By age groups, a greater than 25% decrease in mean arterial pressure was seen in 47% of patients younger than 2 years of age, 43% of those aged 2–11 years, 29% of patients aged 12–16 years, and 27% of those 17 years or older.
A lower starting dose of 0.05 mg/kg may be needed for the youngest patients, the investigators suggested.
Fourteen percent of patients received dosages up to 0.05 mg/kg, 60% received 0.05–0.1 mg/kg, and 26% got more than 0.1 mg/kg. Most patients (63%) received isradipine capsules; the rest got a suspension formulation.
Among the diagnoses that contributed to the acute hypertension, four were predictive of significant decreases in blood pressure with isradipine therapy: renal disease, nonrenal transplant, oncologic disease, and neurologic disease.
Treatment produced another adverse effect—a significant pulse increase of seven pulses per minute among the whole cohort. By dosage category, however, the changes in pulse were not significant with dosages of 0.05 mg/kg or less (an extra three pulses per minute), but were significant at higher doses (an extra seven or eight pulses per minute).
Forty adverse events in 33 patients included emesis, headache, nausea, hypotension, flushing, feeling hot, dizziness, and lightheadedness. Adverse events were not necessarily dose dependent, Dr. Miyashita said.
The investigators did not disclose relevant conflicts of interest.
Study limitations include its retrospective, uncontrolled design, incomplete documentation of adverse events, and misclassification of diagnoses.