Prolonged intermittent hemodialysis using a standard dialysate flow rate for severe overdose of sustained-release...

Valproic acid poisoning can be life threatening and may require urgent extracorporeal elimination. In particular, sustained-release formulations pose a challenge, as conventional short-duration intermittent hemodialysis may fail to remove the drug sufficiently because of delayed and prolonged drug absorption. While prolonged intermittent hemodialysis is a rational alternative, its clinical effectiveness and safety in cases of severe sustained-release sodium valproate overdose have not been reported.

A woman in her 20 s developed coma after ingesting 45 g (approximately 1100 mg/kg) of sustained-release VPA. Prolonged IHD was delivered for 22 h using a blood flow rate (Qb) of 180 mL/min and a dialysate flow rate (Qd) of 500 mL/min. Her consciousness improved in parallel with a marked decline in serum VPA levels, and she was discharged without any neurological sequelae. A two-point, on-dialysis apparent elimination half-life was estimated to be approximately 2.35 h.

In this case, prolonged IHD appeared to have an effect in decreasing VPA concentrations and was safely implemented with monitoring.