Chapter 4 Flashcards
What is bio transformation
Is breaking down of a drug into its metabolites via the action of various enzymes
What is metabolite
This is the product from enzymatic transformation of a drug
Where does bio transformation typically occur
In liver, but can be in places like stomach or kidneys
Explain phase 1 of bio transformation
Involves p450 enzymes and produces water soluble mtabolites
What are Active metabolites
These are metabolites that have useful pharmacological effects
What happens in phase 2 of bio transformation
It involves the process of conjugation for metabolites produced in phase 1 that makes them less able to passively diffuse across memebranes
What are agonist
They activate neurotransmitter receptors
Partial agonists define
Activate receptors but to a lesser degree that full agonist drugs
Used in treatment of drug addiction
Ceiling effect
Not strongly enough to cause overdose but stimulates the recptors
Antagonist
Fail to activate a neurotransmitter receptor or blocks it.
Work on ionotropic receptors
Competitive antagonist
Bind and block neurotransmitter binding
Non competitive antagonist
Will bind and inactivate channel.
Allosteric regulators
Substances that bind to protein but do not activate the protein
Upregulate or downregulate receptor response to nt
Positive modulators
Bind to allosteric sites on receptor and increase ability of nt to bind or activate the receptor
Negative modulators
Bind to allosteric sites and decrease the ability of neurotransmitter to bind and/or activate the receptor.
Chronically asmisnistration
Repeated use of drug making ne adapt to it
Tolerance
Caused by chronic use
Is a drug adaptation that requires escalating drug doses to get desired effects
Pharmacokinetic tolerance
Changes in metabolic process.
Also called drug dispositional tolerance
Pharmacodynamic tolerance
Changes at the synapse
Changes in the number of neurotransmitter receptors. (The receptors get worn out)
Occurs when there is a reduced response to drug’s site of action
Can be seen in drugs like ecstasy.
Behavioral tolerance
Reduced behavioral response to drug’s effect.
Involves cognitive adaptation to chronic drug use.
E.g., people performing better under influence of alcohol
Conditioned or contingent tolerance
Also cognitive adaptation
Associate environmental stimuli with drug taking.
Cross-tolerance
Drugs acting on similar receptors or neurotransmitters.
So if tolerant to heroin, you get tolerant to drugs in same class.
Sensitization
Chronic use cause increase in responsiveness to drug
Drug dependence
Occurs when a user needs a drug in order to function normally.
Becomes apparent after withdrawal symptoms are seen
Withdrawal syndrome
Set of physicali and psychological symptoms that occur when a person stops using a drug use after dependence
Physical dependence
Presence of physical withdrawal symptoms after cessation. For example, pain, diarhea
Psychological dependence
Changepresence of psychological withdrawal symptoms, e.g., changes in mood and strong drug cravings
