Glossary of Pharmacology 

Tolerance 

Processes that result in the reduction of therapeutic effectiveness. Tolerance can occur acutely (tachyphylaxis) or over time due to physiological changes that result in drug desensitization and/or enhanced metabolism.

Tolerance can result in decreased therapeutic efficacy by limiting the drug response over time. Clinically, this can impact dosing, requiring larger doses, drug holidays, or a combination of drugs acting on different targets to achieve the desired therapeutic response over longer periods of time.

Linked terms:  Desensitization, tachyphylaxis

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