This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
In recommending treatment for your carcinoid patient, you will consider all of the following except 
Select and explain. 
A. Cyproheptadine, B. Ketanserin, C. Methysergide, D. Sumatriptan
D: Sumatriptan
Answer: D: Sumatriptan 
Explanation: All of the drugs listed have significant blocking effects on 5HT receptors except sumatriptan, which is an agonist at 5HT1 receptors.