Pharmacology Use of phentolamine is of relatively little value: A In treatment of essential hypertension . B To prevent hypertension during operative removal of pheochromocytoma. C To treat male sexual dysfunction. D To treat hypertension due to clonidine withdrawal. 💡 Explanation Use of phentolamine is of relatively little value: ✓ Correct Answer: A. In treatment of essential hypertension .