Which compendium provides the US drug information and is published annually?

• A. US Pharmacopeia
• B. British Pharmacopoeia
• C. Merck Manual
• D. Physicians' Desk Reference

Answer: (A)

The main idea here is identifying the official US reference that defines drug standards and information. The United States Pharmacopeia (USP) is the authoritative compendium used in the US to set standards for drug substances and products, including identity, strength, quality, and purity. It is published in a combined format as USP–NF and is updated annually, with updates and supplements to reflect new findings and products. That official status and the regular annual updates are why it’s the best answer for a question about US drug information in a compendium form.

The British Pharmacopoeia is the UK’s official standards and not US-based. The Merck Manual is a general medical reference, not the standard compendium for drug substances. The Physicians’ Desk Reference (PDR) is a drug information resource focused on labeling and prescribing details, but it isn’t the official US drug standards compendium and isn’t the primary source for standardizing drug quality.