Which of the following are adverse effects of niacin?

All of the above

(E) correctly describes the adverse effects of niacin. The following explains why. One of the major adverse effects of niacin is flushing. Prostaglandin synthesis mediated via nicotinic acid, which is coupled to cyclooxygenase. Prostaglandin D is released from macrophages and causes cutaneous vasodilation. This can be remedied with aspirin, ibuprofen, etc. Aspirin 81 mg PO is commonly used to prevent the flushing, but the flushing may go away on its own in a few weeks. Exacerbation of a peptic ulcer is another big gastrointestinal issue with niacin. The issue is large enough that in those who have a history of peptic ulcers, niacin is contraindicated. Hyperglycemia is mainly a problem in those that are uncontrolled. Myopathy is a problem with statins for some. While the myopathy for niacin is not as problematic, the concern is still there. Actually, for patients who cannot take statins for whatever reason, niacin is a good choice.