Zero order kinetics occur in following drug with high dose:
**Core Concept**
Zero-order kinetics refers to a type of pharmacokinetic behavior where the rate of drug elimination is constant and independent of the drug concentration. This occurs when the elimination process is saturated, such as with high doses of drugs that are metabolized by a single enzyme.
**Why the Correct Answer is Right**
In zero-order kinetics, the rate of elimination is constant and not dependent on the concentration of the drug. This is because the enzyme responsible for metabolizing the drug is saturated, meaning it is working at its maximum capacity and cannot metabolize the drug any faster, regardless of the concentration. This can occur with high doses of certain drugs that are metabolized by a single enzyme.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because first-order kinetics, not zero-order kinetics, is typically associated with low doses of drugs. In first-order kinetics, the rate of elimination is proportional to the concentration of the drug.
**Option B:** This option is incorrect because it is not a specific example of a drug that exhibits zero-order kinetics with high doses.
**Option C:** This option is incorrect because it does not provide a clear example of a drug that exhibits zero-order kinetics with high doses.
**Clinical Pearl / High-Yield Fact**
Zero-order kinetics can lead to non-linear pharmacokinetics, where small changes in dose can result in large changes in plasma concentration.
**Correct Answer: C. Digoxin**
Digoxin is a cardiac glycoside that is metabolized by a single enzyme, making it a classic example of a drug that exhibits zero-order kinetics with high doses.