**Coasting Effect**

**Core Concept**
The coasting effect refers to the phenomenon where the therapeutic effect of a medication persists even after its plasma concentration has decreased below the minimum effective concentration (MEC). This is often seen with medications that have a long half-life or are highly tissue-bound, allowing them to maintain a therapeutic effect despite declining plasma levels.

**Why the Correct Answer is Right**
The coasting effect is primarily observed with medications that have a high degree of protein binding, such as warfarin, phenytoin, and digoxin. These medications bind extensively to plasma proteins, resulting in a large volume of distribution and a prolonged half-life. As the plasma concentration of these medications decreases, the bound fraction remains in the body, continuing to exert a therapeutic effect.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not directly relate to the concept of coasting effect.
**Option B:** This option is incorrect as it does not accurately describe the phenomenon of coasting effect.
**Option C:** This option is incorrect as it is not directly related to the concept of coasting effect.

**Clinical Pearl / High-Yield Fact**
When managing patients on medications with a high degree of protein binding, it is essential to monitor their plasma concentrations and adjust dosages accordingly to avoid toxicity. Additionally, the coasting effect can be a contributing factor to the development of tolerance or resistance to certain medications.

**Correct Answer: D.**