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
After taking some drug for the classic acute attack of a migraine, a patient developed nausea and vomiting. He also developed tingling and numbness in the tip of the finger that also turned blue. Which of the following is the most likely drug implicated in causing the above vasoconstricting 
Select and explain. 
A. Dihydroergotamine, B. Sumatriptan, C. Aspirin, D. Butorphanol
A: Dihydroergotamine
Answer: A: Dihydroergotamine 
Explanation: This is a classic sign of ergot induced vasoconstriction. Dihydroergotamine can be used for an acute attack of a migraine and can result in these symptoms. Due to their vasoconstricting potential, ergot alkaloids are contra-indicated in a patient with peripheral vascular disease. These may also lead to the development of gangrene.