This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autacoids, Subject name: Pharmacology
Which is not a 2nd generation anti-histamine agents 
Select and explain. 
A. Cetirizine, B. Cyclizine, C. Loratidine, D. Fexofenadine
B: Cyclizine
Answer: B: Cyclizine 
Explanation: Anti histamines are classified into first generation and second generation compounds on the basis of CNS penetration and anti cholinergic propeies. First generation anti-histamine can penetrate blood brain barrier and possess additional anti cholinergic propeies which are lacking in second generation drugs. Cyclizine is a first generation where as cetrizine, loratidine and fexofenadine are second generation drugs Refer Goodman & Gilman 12/e p921