This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sedative-Hypnotics and Parkinsonism, Subject name: Pharmacology
Carbamazepine in elderly patient can cause 
Select and explain. 
A. Hyponatremia, B. Hypokalemia, C. Hyperkalemia, D. Hypernatremia
A: Hyponatremia
Answer: A: Hyponatremia 
Explanation: - Carbamazepine DOC for focal seizures DOC for trigeminal neuralgia Used for Diabetes insipidus Bipolar disorder Adverse effect - Release of ADH (leading to dilutional hyponatremia), Agranulocytosis, Aplastic anaemia