The Safety of Rapid Valproic Acid Infusion

Abstract

Purpose: The recommended rate of administration of valproic acid injection is 20 mg/min. Drug delivery at this rate may be inadequate for expeditious control of seizures. The safety of rapid infusion of valproic acid has not been established, and this study was designed to explore the effects of rapid infusion in patients with acute seizures. Methods: Twenty patients with acute repetitive seizures received 20 mg/kg loading doses of valproic acid. Infusion rates ranged from 33.3 to 555 mg/min (median, 200 mg/min). Sixteen patients had received previous or concomitant antiepileptic drugs, with inadequate seizure control. Heart rate, blood pressure, and respiratory rate were measured before infusion and at frequent intervals for 1 hour after infusion. Patients were also observed for changes in level of alertness and signs of local irritation. Results: No patient exhibited a decline in level of conscious ness or respiratory function. Two patients with significant con tributing factors exhibited declines in blood pressure requirinj vasopressors. No significant local irritation was reported. Al though efficacy was not a measured end point, seizures wen abolished in all patients. Conclusions: Infusion of valproic acid at rates between 3! and 555 mg/min is well tolerated. No serious adverse effect attributable to the rapid infusion of valproic acid were encoun tered, although valproic acid, along with other factors, ma; have contributed to the hypotension in two patients. Intrave nous valproic acid is an option for the control of acute seizures.