In physiology, tolerance occurs when an organism builds up a resistance to the effects of a substance after repeated exposure. This can occur with environmental substances such as salt or pesticides. It is also commonly encountered in pharmacology (see drug tolerance), when a subject's reaction to a drug (such as a painkiller or intoxicant) decreases so that larger doses are required to achieve the same effect. Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ... Pharmacology (in Greek: pharmacon (ÏάÏμακον) meaning drug, and logos (λÏγοÏ) meaning science) is the study of how chemical substances interact with living systems. ... Drug tolerance occurs when a subjects reaction to a drug (such as a painkiller or intoxicant) decreases so that larger doses are required to achieve the same effect. ...
Tolerance levels are determined by government agencies such as the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA), and are based on the results of testing, primarily animal testing.
Tolerance levels also are criticized for not recognizing threats to at-risk populations such as children, the elderly, and pregnant women.
It is also commonly encountered in pharmacology (see drug tolerance), when a subject's reaction to a drug (such as a painkiller or intoxicant) decreases so that larger doses are required to achieve the same effect.
Drug tolerance occurs when a subject's reaction to a psychopharmaceutical drug (such as a painkiller or intoxicant) decreases so that larger doses are required to achieve the same effect.
Tolerance may be related to the familiarity of "drug onset cues".
Many law enforcement and civic agencies (such as schools and scouting groups) advocate a zero tolerance policy towards drugs, meaning that any infraction of existing laws and regulations will be punished, no matter how small.