This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacokinetics, Subject name: Pharmacology
A 32yr old patient came to the Gyne. OPD with complains of bleeding per vaginum . Bleeding was for a prolonged period of time than her usual number of days in her regular menses. There was no significant finding on examination. On fuher examination, she told that she was on warfarin therapy for past 1 yr. And also told that she took some medication recently before the symptoms appear. Which of the following drug is not responsible for the condition ? 
Select and explain. 
A. Clarithromycin, B. Sulphonamide, C. Ciprofloxacin, D. Carbamazepine
D: Carbamazepine
Answer: D: Carbamazepine 
Explanation: These are those drugs which inhibit cyt 450 and increase the half life of warfarin resulting in increased bleeding.sulphonamides don't allow degradation of warfarin : Increased bleeding, but carbamazepine is enzyme inducer and hence not responsible for the condition and decreases the half life of warfarin leading to decreased activity. Must know table: