All of the following are adverse effects of nicotinic acid except-
**Core Concept**
Nicotinic acid, also known as niacin, is a form of vitamin B3 used to treat high cholesterol, type 2 diabetes, and pellagra. Its adverse effects are primarily related to its vasodilatory properties and its impact on lipid metabolism.
**Why the Correct Answer is Right**
Nicotinic acid works by inhibiting the breakdown of triglycerides in adipose tissue, which leads to increased levels of free fatty acids in the bloodstream. This results in vasodilation, particularly in the cutaneous blood vessels, causing flushing, itching, and redness. Additionally, nicotinic acid can cause elevations in liver enzymes, glucose intolerance, and gout due to its effects on lipid metabolism.
**Why Each Wrong Option is Incorrect**
**Option A:** While gastrointestinal side effects such as nausea and diarrhea are common with nicotinic acid, they are not the only adverse effects.
**Option B:** Skin reactions like flushing are a well-documented side effect of nicotinic acid, so this option is not correct.
**Option C:** Liver enzyme elevations are indeed an adverse effect of nicotinic acid, making this option incorrect.
**Clinical Pearl / High-Yield Fact**
To reduce the risk of skin flushing, nicotinic acid is often given at bedtime with a snack or meal to minimize its effects on blood vessels.
**Correct Answer:** D.