NAPLEX (North American Pharmacist Licensure Examination) Practice Exam 2026 - Free NAPLEX Practice Questions and Study Guide

The Friedewald equation should not be used if the level of triglycerides (TG) is greater than 400 mg/dL. This is because at such high levels, it can lead to inaccurate calculations of LDL cholesterol. LDL cholesterol is an important marker for cardiovascular risk, and its accurate measurement is crucial for proper diagnosis and treatment. Therefore, it is important to consider other methods for calculating LDL cholesterol, such as direct measurement, if TG levels are very high.

Option A is incorrect because a TG level of less than 200 mg/dL is actually a requirement for using the Friedewald equation.

Option B is incorrect because a HDL level higher than 60 mg/dL does not affect the accuracy of the Friedewald equation.

Option D is incorrect because a LDL level lower than 100 mg/dL falls within the normal range and is not a cause for concern when using the Friedewald equation.