This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
Metyrosine given in: 
Select and explain. 
A. Malignant pheochromocytoma, B. Addisons disease, C. Depression, D. Hypertensive emergency
A: Malignant pheochromocytoma
Answer: A: Malignant pheochromocytoma 
Explanation: Ans. a. Malignant pheochromocytomaRef: Goodman Gilman 13th E/P141Metyrosine competitively inhibits tyrosine hydroxylase, thereby decreasing norepinephrine synthesis in the neurons.It is used for treatment of hypertension in patients with pheochromocytoma prior to surgery along with phenoxybenzamine, which is the drug of choice.It is also used in malignant pheochromocytoma for long term management.