What is drug tolerance?

Drug tolerance is a phenomenon in which the body becomes accustomed to a drug over time, leading to a diminished response to its effects. As a result, individuals may require higher doses of the drug to achieve the same therapeutic or desired effect that was initially achieved with a lower dose. This can occur due to various physiological adaptations, such as receptor desensitization or increased drug metabolism, which contribute to the body's adjustment to the presence of the drug.

In contrast, the other options describe different concepts. Becoming more sensitive to a drug implies hyper-sensitivity, which is not related to tolerance. The requirement for lower doses to achieve the desired effect aligns more closely with the concept of drug sensitivity or increased potency—not tolerance. A decrease in the drug's biological half-life refers to changes in how long a drug remains active in the body, which is distinct from tolerance. Understanding drug tolerance is crucial for managing medication regimens, particularly in chronic conditions or addiction, where individuals might need to adjust dosages to maintain efficacy.