This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NSAIDs, Gout and Rheumatoid Ahritis, Subject name: Pharmacology
Erectile dysfunction is caused by:- 
Select and explain. 
A. Antihistamines, B. Leukotriene antagonists, C. Thyroxine, D. Insulin glargine
A: Antihistamines
Answer: A: Antihistamines 
Explanation: Drugs causing erectile dysfunction. Diuretics Thiazides Antihypeensives Beta blockers Calcium channel blockers Cardiac drugs Gemfibrozil Clofibrate Antidepressants SSRI TCA MAO inhibitors H2 antagonists Cimetidine Hormones GnRH agonists 5 alpha reductase inhibitors Others Ethanol Cocaine Marijuana Cimetidine (but not other H2 blockers) has antiandrogenic action (displaces dihydrotestosterone from its cytoplasmic receptor), increases plasma prolactin and inhibits degradation of estradiol by liver. High doses given for long periods have produced gynaecomastia, loss of libido, impotence and temporary decrease in sperm count.