What is Tolerance ?
In drugs abuse Tolerance is defined as the need to increase the dose progressively in order to produce the effect originally achieved by smaller amounts.
As Tolerance is a progressive increase in dosage, it may be several hundred fold greater than the first dose after a short period of time.
In addiction to drugs, alcohol and other substances is common to find tolerance and physical or psychological dependence. The elimination of such drugs or alcohol triggers a withdrawal syndrome. For example, we will find physical dependence, tolerance and withdrawal in heroin addiction.
(Edited by Dra Moya Guirao)