Tolerance is defined as which of the following?

Tolerance is defined as which of the following?

• A. Reduced response during a single dose
• B. Rapid desensitization
• C. Decreased efficacy only with acute dosing
• D. Reduction in response after repeated administration

Answer: (D)

Tolerance means the drug’s effect diminishes after repeated exposure, so the same dose produces a smaller response over time and higher doses may be needed to achieve the same effect. This interpretation fits because it specifically describes a change that develops with continued use, not just a single dose. In contrast, a reduced response within a single dose is tachyphylaxis, a rapid and acute decrease in response. Rapid desensitization refers to a fast, reversible loss of responsiveness often under special conditions, and it’s not the same as tolerance from repeated use. Decreased efficacy only with acute dosing would misstate the timing entirely, since tolerance is about changes after repeated administration.

Tolerance means the drug’s effect diminishes after repeated exposure, so the same dose produces a smaller response over time and higher doses may be needed to achieve the same effect. This interpretation fits because it specifically describes a change that develops with continued use, not just a single dose.

In contrast, a reduced response within a single dose is tachyphylaxis, a rapid and acute decrease in response. Rapid desensitization refers to a fast, reversible loss of responsiveness often under special conditions, and it’s not the same as tolerance from repeated use. Decreased efficacy only with acute dosing would misstate the timing entirely, since tolerance is about changes after repeated administration.