Which side effect is extremely common with nicotinic acid?

• A. Nausea
• B. Hot flashes
• C. Gas
• D. Hepatotoxicity

Answer: (B)

Niacin most reliably causes a skin flushing reaction with a sensation of warmth, often on the face and upper body, sometimes with itching. This occurs because niacin triggers prostaglandin release in the skin, leading to dilation of superficial blood vessels. The effect is dose-dependent and especially common with immediate-release forms, though it can be reduced by taking aspirin beforehand or by using an extended-release formulation. Other listed effects can occur but are less consistently seen: nausea and gas can happen, but are not as characteristic, while hepatotoxicity is a potential risk with long-term high-dose therapy—more serious but not as universally occurring as flushing. So the extremely common side effect is hot flashes.