Intentional use of ertapenem to reduce valproic acid concentrations in overdose: two case reports

Introduction Valproic acid (VPA) is used for the treatment of seizures and other conditions. Overdose present as central nervous system and respiratory depression, metabolic acidosis, and hyperammonemia. Management is mainly supportive, including activated charcoal, L-carnitine, and hemodialysis. Multiple reports have demonstrated reductions in therapeutic VPA concentrations with carbapenems.Case report 1 A 23-year-old male with bipolar disorder ingested 40 g of VPA. The initial VPA and ammonia concentrations were 300 µg/L and 192 µg/dL, respectively. The peak VPA and ammonia concentrations reached 894 µg/L and 740 µg/dL, respectively. He received multi-dose activated charcoal, L-carnitine, and ertapenem, followed by continuous renal replacement therapy (CRRT). His concentrations decreased rapidly, and he was extubated.Case report 2 A 33-year-old male ingested 10 g of VPA, multiple psychotropics, and alcohol. He had a GCS of 10, hypoxemia, and initial VPA and ammonia of 45 µg/L and 139 µg/dL, respectively. The peak VPA and ammonia were 317 µg/L and 255 µg/L, respectively. He received L-carnitine and ertapenem, with a subsequent decline in concentrations.Discussion Carbapenems may reduce VPA concentrations by 50%–80%. Our cases demonstrate the successful use of ertapenem in the management of severe VPA toxicity. Further studies may establish criteria for the use of carbapenems for treating VPA poisoning and whether they can reduce the need for hemodialysis.