4302
Possible pathophysiological mechanisms which may have been operative in this case include : a direct central nervous system ( CNS ) toxic effect of valproic acid ; a paradoxical epileptogenic effect secondary to the drug ; and an indirect CNS toxic effect mediated through valproic acid - induced hyperammonemia .
 hyperammonemia, valproic acid
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: adverse effect 
Text: {0} 
Answer:
 hyperammonemia, valproic acid