NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

What reference is used for drug substitution?

1. FDA's Orange book: therapeutic equivalents

2. FDA's Purple book: biosimilar equivalents

3. Medi-Span Price Rx

4. CDC

The correct answer is: FDA's Orange book: therapeutic equivalents

Drug substitution refers to the practice of dispensing a drug with a different product than what was prescribed. The FDA's Orange Book is the primary reference used for drug substitution, as it lists all FDA-approved therapeutic equivalents of brand-name drugs. The options B, C, and D are incorrect because they do not provide the same comprehensive information on therapeutic equivalents. The FDA's Purple Book is specifically for biosimilar products, not all therapeutic equivalents, while Medi-Span Price Rx provides pricing information rather than substitution information. The CDC does not provide information on therapeutic equivalents at all. Therefore, the FDA's Orange Book remains the most relevant and reliable reference for drug substitution.