Problems for Discussion - 2 - Anticonvulsants - Valproate

A 19-year-old female (50 kg) presents to hospital 1.5 hours following a reported ingestion of 30 x 500 mg Epilim® enteric-coated valproic acid tablets. She is awake and alert, P95 bpm, BP 100/50, GCS 15. Fifty grams of activated charcoal were administered on arrival. The emergency physician at your hospital rings for advice on when he can discharge her home. Her initial valproic acid level 2 hrs post-ingestion is 400 micromole/L.

1. What would you advise the attending physician regarding discharge of this patient?
2. What advice would you give regarding gastrointestinal decontamination for this patient?

A 26-year-old female (60 kg) with bipolar affective disorder was admitted to the intensive care unit from the emergency department after a reported ingestion of 70 x 500 mg enteric coated valproate. The time of ingestion was unknown. The patient had a non-focal neurological exam but was unconscious on arrival and intubated. P 110, BP 110/50, T 37.2. One dose of activated charcoal 50 g was given via a nasogastric tube. Her serum biochemistry and LFTs were normal and paracetamol level was undetected. Her initial valproic acid level was 2000 micromole/L. Serum ammonia was also normal. Initial attempts at whole bowel irrigation had been unsuccessful and the patient had absent bowel sounds.

You are consulted about her care. The ICU staff would like to know what to expect clinically in the next few hours and what else they should do to manage her.

1. What advice would you give regarding this patient’s potential clinical course?
2. What would you advise as the indications for extracorporeal removal of valproate?
3. What are the advantages and disadvantages of haemodialysis and haemoperfusion in the enhanced elimination of valproate?
4. Is there any role for repeat doses of nasogastric charcoal in this patient?