What is the term for an increased tolerance to a drug with repeated injections?

What is the term for an increased tolerance to a drug with repeated injections?

• A. Tachyphylaxis
• B. Tolerance
• C. Dependence
• D. Sensitization

Answer: (A)

Tachyphylaxis refers to a rapid loss of a drug’s effect after repeated exposure, often within minutes to hours. This quick desensitization occurs as the body responds to consecutive doses by mechanisms such as receptor desensitization or downregulation, depletion of mediators, or rapid changes in signaling pathways. Because the question highlights an increased tolerance with repeated injections, the fast onset of reduced response fits tachyphylaxis best. In contrast, tolerance describes a more gradual decrease in effectiveness that develops over days to weeks, often requiring higher doses to achieve the same effect and can involve pharmacokinetic or pharmacodynamic changes. Dependence is about the body adapting to a drug such that withdrawal symptoms occur if the drug is stopped. Sensitization is the opposite process, where repeated exposure increases the drug’s effect rather than diminishing it.

Tachyphylaxis refers to a rapid loss of a drug’s effect after repeated exposure, often within minutes to hours. This quick desensitization occurs as the body responds to consecutive doses by mechanisms such as receptor desensitization or downregulation, depletion of mediators, or rapid changes in signaling pathways. Because the question highlights an increased tolerance with repeated injections, the fast onset of reduced response fits tachyphylaxis best.

In contrast, tolerance describes a more gradual decrease in effectiveness that develops over days to weeks, often requiring higher doses to achieve the same effect and can involve pharmacokinetic or pharmacodynamic changes. Dependence is about the body adapting to a drug such that withdrawal symptoms occur if the drug is stopped. Sensitization is the opposite process, where repeated exposure increases the drug’s effect rather than diminishing it.