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
Which of the following drug is not a component of triple drug therapy for helicobacter pylori: March 2008 
Select and explain. 
A. Lansoprazole, B. Clarithromycin, C. Metronidazole, D. Cimetidine
D: Cimetidine
Answer: D: Cimetidine 
Explanation: Ans. D: Cimetidine Triple therapy is considered to be the standard treatment for children. A proton pump inhibitor combined with two antibiotics has been shown to be very effective in clearing H pylori from the stomach. The current recommendation is treatment with amoxicillin, clarithromycin, and a proton pump inhibitor (lansoprazole) for 2 weeks.