Regarding termination of drug action:
- Drug action may be terminated either by liver metabolism or by renal excretion. It is not necessary to be excreted from the body.
- By metabolism of the drug, most drugs will be inactivated, but some may be activated.
- Some drugs give their action after distribution into the tissues.
Drugs must be excreted from the body to terminate their action
Metabolism of drugs always abolishes their pharmacologic activity
Hepatic metabolism and renal excretion are the two most important mechanisms involved
Distribution of a drug out of blood stream terminates the drug's effects