This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pharmacology
Which of the following is not an H2 blocker - 
Select and explain. 
A. Cimetidine, B. Oxyphenonium, C. Roxatidine, D. Ranitidine
B: Oxyphenonium
Answer: B: Oxyphenonium 
Explanation: Ans. is 'b' i.e., Oxyphenonium Drugs for peptic ulcer1. Reduce gastric acid secretiona) H2 antihistaminic - Cimetidine, Ranitidine, Famotidine, Roxatidine.b) Proton pump inhibitors - Omeprazole, Lansoprazole, Pantoprazole, Rabeprazole, Esomeprazole.c) Anticholinergics - Pirenzepine, propantheline, oxyphenonium,d) Prostaglandin analogue - Misoprostol, enprostil, rioprostil.2. Neutralization of gastric acid (antacids)a) Systemic - Sodium bicarbonate, sodium citrate.b) Non systemic - Magnesium hydroxide, Mag. trisilicate, aluminium hydroxide, Magaldrate, calcium carbonate.3. Ulcer protectives Sucralfate, colloidal bismuth subcitrate, Prostaglandin analogue.4. Anti H. pylori durgs Amoxicillin, clarithromycin, metronidazole, Tinidazole, tetracycline.Note - PG analogue have both antisecretory (| HC1 secretion) as well as cytoprotective action.