This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diuretics and Antidiuretics, Subject name: Pharmacology
Spironolactone is contraindicated with which of the following drugs? 
Select and explain. 
A. Enalapril, B. Atenolol, C. Verapamil, D. Chlorthiazide
A: Enalapril
Answer: A: Enalapril 
Explanation: Ans. (A) Enalapril(Ref: KDT 8/e p635)*Spironolactone is a K+ sparing diuretic. It should be used cautiously if the patient is receiving K+ salts or drugs increasing serum K+ levels.*ACE 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.