This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Carbamazepine in elderly causes ? 
Select and explain. 
A. Hypernatremia, B. Hyponatremia, C. Hyperkalemia, D. Hypokalemia
B: Hyponatremia
Answer: B: Hyponatremia 
Explanation: Ans. is 'b' i.e., Hyponatremia o Carbamazepine can cause hyponatremia and water intoxication at high doses. This adverse effect appears to he due to its ADH releasing propey (resulting in dilutional hyponatremia). The same adverse effect can be utilized for treatment of diabetes insipidus.