This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
Which drug is likely to cause livedo reticularis? 
Select and explain. 
A. Gabapentin, B. Amantadine, C. Pramipexole, D. Levodopa
B: Amantadine
Answer: B: Amantadine 
Explanation: Ans. B. AmantadineAmantadine is antiviral agent used in parkinsonism. It increases the dopamine levels by inhibiting its reuptake and have anticholinergic effect. It causes discoloration of skin, livedo reticularis as side effect.