Asterixis associated with sodium valproate

Intoxication with most anticonvulsants can produce asterixis. Asterixis rarely occurs with therapeutic serum anticonvulsant levels. We report two patients with asterixis who were taking valproic acid and had serum levels within the therapeutic range. Neither patient had clinical or laboratory evidence of hepatotoxicity. Only one other patient has been reported with valproate-associated asterixis in the absence of toxic serum drug levels or hepatotoxicity. Asterixis seems to be due to a central effect of the drug unrelated to hepatotoxicity or sedation.