Adaptation to drugs

Adaptation to drugs may be seen in the following ways:

• therapeutic effects through adaptation:
  • immunization, tricyclics
• tolerance increasing ineffectiveness of therapy:
  • target cell tolerance - e.g. depletion of NA by ephidrine nosedrops - allergic rhinitis
  • physiological homeostatic mechanisms, e.g. hydralazine
  • reflex tachycardia
• adaptation to drugs:
  • metabolic autoinduction - e.g. barbiturates, carbamazepine
• withdrawal symptoms can be caused by:
  • opiates, alcohol, benzodiazepines, clonidine, corticosteroids, organic nitrates, beta blockers, enzyme inducers, etc.
• adverse effects directly due to adaptation:
  • tardive dyskinesia due to dopamine antagonists