What is the definition of a formulary?

A formulary is defined as a list of drugs preferred by a particular prescription plan. This means that the formulary outlines medications that are covered under a specific health insurance policy, often designed to manage costs and ensure that patients receive the most effective treatments. Typically, formularies categorize drugs into tiers based on their cost and efficacy, influencing what patients will pay out-of-pocket for each medication.

This definition highlights the role that formularies play in the broader context of healthcare, where they serve as a tool for insurance providers to negotiate prices with pharmaceutical companies and to guide healthcare providers in prescribing medications, ensuring that they make choices that are both clinically appropriate and financially sensible for patients.

The other options do not accurately capture the specific purpose of a formulary. While a complete list of all medications available in a pharmacy or a guide to drug interactions may be useful resources, they do not pertain to the preferred status and cost considerations set by a prescription plan. Similarly, while a list of controlled substances is important for regulatory and safety reasons, it does not describe the preferred medication framework that a formulary represents.