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
[{'content': 'Spironolactone is contraindicated with which of the following drugs: \nSelect and explain. \nA. Enalapril., B. Atenolol., C. Verapamil., D. Chlorthiazide.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Spironolactone is a K+ sparing diuretic. It should be used cautiously if the patient is receiving K+ salts or drugs increasing serum K+ levels.\n\nACE inhibitors can also cause hyperkalemia as an adverse effect. If these are combined with K+ sparing diuretics, cardiac arrhythmia due to high serum K+ levels may develop', 'role': 'assistant'}]