This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epilepsy, Subject name: Pharmacology
If carbamazepine is added to valproate, which side effect of valproate can increase? 
Select and explain. 
A. Thrombocytopenia, B. Hepatotoxicity, C. Hyperammonemia, D. Pancreatitis
B: Hepatotoxicity
Answer: B: Hepatotoxicity 
Explanation: Valproate is metabolized by cytochrome P450 and produce a metabolite which is hepatotoxic Carbamazepine is enzyme inducer which cause the induction of its metabolism and produce more metabolite, thus causing hepatotoxicity