National Certified Addiction Counselor, Level 2 (NCAC II) Practice Exam Exam

Which term refers to the ratio between the effective dose and toxic dose of a medication?

1. Therapeutic Window

2. Therapeutic Index

3. Safety Profile

4. Margin of Safety

The correct answer is: Therapeutic Index

The term that refers to the ratio between the effective dose and the toxic dose of a medication is the Therapeutic Index. This concept is fundamental in pharmacology and helps healthcare professionals understand the safety and efficacy of a drug. The Therapeutic Index provides important information about a medication's safety margin. A high therapeutic index indicates that there is a wide margin between the effective dose and the toxic dose, which generally suggests a safer medication. In contrast, a low therapeutic index implies that there is a smaller margin between effective and toxic doses, increasing the risk of adverse effects and requiring closer monitoring of patient responses to the medication. Understanding the therapeutic index is crucial for dosage adjustments and for preventing toxicity in patients. Other terms, while related to medication safety, do not specifically define this ratio in the way that Therapeutic Index does. The Safety Profile generally refers to a broader understanding of the risks associated with a drug rather than focusing specifically on the ratio of doses. The Margin of Safety is closely related but is typically defined as the difference between a drug's effective dose and its lethal dose rather than its toxic dose. Therefore, the Therapeutic Index is the most precise term for describing the balance between efficacy and toxicity in medication use.