Registered Practical Nurse (RPN) Practice Test

What is indicated when a client needs larger doses of medication to achieve the same therapeutic effect?

1. Desensitization

2. Tolerance

3. Dependency

4. Resistance

The correct answer is: Tolerance

The need for larger doses of medication to achieve the same therapeutic effect is referred to as tolerance. Tolerance occurs when the body becomes accustomed to a drug after prolonged use, leading to a reduced response to its effects. This phenomenon is common with certain medications, particularly those affecting the central nervous system, such as pain relievers, sedatives, or stimulants. As a result, the dosage must be increased to reach the desired therapeutic outcome. In contrast, desensitization typically involves a decrease in the responsiveness of a receptor after continuous exposure to an agonist. Dependency refers to a state where withdrawal symptoms occur when a drug is not taken, highlighting a physical or psychological reliance on the substance. Resistance is often used to describe a situation where microbial populations, such as bacteria, become less susceptible to antibiotics, not directly related to medication dosages in the context of patient care. Thus, tolerance is the most accurate term to describe the situation of needing larger doses to achieve the same therapeutic effect.