Drug tolerance

pharmacological concept describing subjects' reduced reaction to a drug following its repeated use

Drug tolerance (or physiological tolerance) is a term used to describe that the organism gets used to a given substance. Drug tolerance also means that over time a drug becomes less effective and larger amounts of the substance are needed to get the same effect.[1]

Physiological tolerance can be achieved in one of the following ways:

  1. By changing the number of receptors for a substance
  2. By changing the way the signal is handled
  3. By changing the receptors themselves
  4. By changing the system that antagonizes the receptor


  1. "How Do Drug Tolerance and Dependency Set In?". Sunrise House. Retrieved 2020-11-24.