Increased dosage requirement for therapeutic effect is called?

Increased dosage requirement for therapeutic effect is called?

• A. Side Effects
• B. Therapeutic Action
• C. Adulteration
• D. Tolerance

Answer: (D)

Tolerance is the phenomenon where repeated exposure to a drug reduces its effect, so a higher dose is needed to achieve the same therapeutic response. This can arise from receptor changes such as desensitization or downregulation, increased drug metabolism, or adaptive cellular mechanisms that blunt the drug’s effect. Clinically, this means dosing may need to be titrated upward over time, with careful monitoring to balance efficacy against the risk of toxicity. It’s different from side effects, which are unwanted effects of a drug, and from the intended therapeutic action. Adulteration is not a pharmacologic concept.

Tolerance is the phenomenon where repeated exposure to a drug reduces its effect, so a higher dose is needed to achieve the same therapeutic response. This can arise from receptor changes such as desensitization or downregulation, increased drug metabolism, or adaptive cellular mechanisms that blunt the drug’s effect. Clinically, this means dosing may need to be titrated upward over time, with careful monitoring to balance efficacy against the risk of toxicity. It’s different from side effects, which are unwanted effects of a drug, and from the intended therapeutic action. Adulteration is not a pharmacologic concept.