This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pituitary-Hypothalmic System and Thyroid, Subject name: Pharmacology
Which of the following drug has visual field defects as an adverse effect? 
Select and explain. 
A. Cabergoline, B. Bromocriptine, C. Pegvisomant, D. Leuprolide
C: Pegvisomant
Answer: C: Pegvisomant 
Explanation: Pegvisomant is GH receptor antagonist Known to cause visual field defect. Pegvisomant given subcutaneously cause toxicity:increase liver enzymes Also known as somatotropin antagonist Bromocriptine and Cabergoline are D2 receptor agonists Leuprolide is GnRH agonist