Chapter 4: Psychopharmacology Flashcards
Psychopharmacology
The study of the effects of drugs on the nervous system and behavior
Drug
An exogenous chemical not necessary for normal cellular functioning that significantly alters the functions of certain cells of the body when taken in relatively low doses
Two major aspects of drug influence:
Drug effects and sites of action
Drug effect
the changes we can observe in an individual’s physiological processes and behavior
Sites of action
the points at which molecules of drugs interact with molecules located on or in cells of the body, thus affecting some biochemical processes of these cells
Psychopharmacologists study drugs that affect the nervous system and behavior in two broad classes: ________ drugs and drugs of _____
therapeutic; abuse
Pharmacokinetics is ___.
the life cycle of a drug molecule.
Steps of pharmacokinetics:
1.) Absorption
2.) Distribution within the body
3.) Metabolized
4.) Excretion
Drug is administered and absorbed through tissues
Absorption
Drug is distributed throughout the body and blood
Distribution
Drug is changed to an inactive form by enzymes (usually in liver)
Metabolism
Drug is excreted in urine by kidneys
Excretion
Routes of drug administration (absorption):
Intravenous injection, intraperitoneal injection, intramuscular injection, subcutaneous injection,
intracerebral administration, intracerebroventricular (ICV) administration, oral administration, sublingual administration, inhalation, topical administration
The fastest route of administration is ________ injection
intravenous
Routes of administration used if the drug can’t cross the blood-brain barrier
Intracerebral administration and ICV administration
The most common route of administration is ________ ______
oral administration
Insufflation, or “snorting,” is considered _______ administration
topical
True or false: Drugs exert effects only at their sites of action
True
Most sites of action are located on or in cells of the CNS/PNS.
CNS
The most important factor in determining the rate of distribution is ____ _______ because ________
lipid solubility; fat molecules can cruise on through the BBB
True or false: Not all drugs are excreted
False, all drugs are eventually excreted, mostly by the kidneys
Many drugs are metabolized and deactivated by _______ in the brain and liver
enzymes
During metabolism, sometimes enzymes transform molecules into ________ versions.
more active
The dose-response curve locates the point of _________ _____.
maximum effect
True or false: most drugs have more than one effect
True
The _________ _____ measures a drug’s margin of safety
Therapeutic index
Why are some drugs more effective than others?
Sites of action; affinity of a drug with its site of action
Affinity
The readiness with which the two molecules join together
The most desirable drug has high/low affinity for sites of action producing therapeutic effects and high/low affinity for sites of action producing toxic side effects
high; low
Often, when a drug is administered repeatedly, its effects _______, which is called tolerance.
diminish
Sometimes a drug becomes more and more effective after repeated administration, called _________.
Sensitization
After someone has built up tolerance to a certain drug and they suddenly stop taking it, they may experience __________ symptoms
withdrawal
Withdrawal symptoms indicates _______ _______.
Physical dependence
Compensatory mechanisms the brain uses in response to repeated use of a drug:
Decrease the effectiveness of binding with receptors; coupling process
An inactive substance that may have physiological or psychological effects
Placebo
The effects of a placebo results from changes in _______, _______, or _______.
motivation, expectation, learning
True or false: Placebo studies for new drugs are required by the FDA
True
______ drugs facilitate postsynaptic effects
Agonist
_________ drugs block or inhibit postsynaptic effects
Antagonists
Most drugs affecting behavior affect ______ _______
Synaptic transmission
A drug that mimics the effects of a neurotransmitter acts as a ______ ______
direct agonist
How do direct agonists work?
Direct agonists attach to the binding site to which the neurotransmitter normally attaches, causing the receptor to respond in the same way as when the neurotransmitter is present.
Some drugs act as antagonists by __________________
preventing release of NTs from the terminal button
Other drugs act as agonists by ______________________
binding with proteins and triggering release of NTs
An analogy for the direct agonist is the right/wrong key in the keyhole
right
An analogy for the receptor blocker (direct antagonist) is the right/wrong key in keyhole
wrong
How do receptor blockers (direct antagonists) work?
Binds with postsynaptic receptors but does not open the ion channel or trigger intracellular events
Another word for a direct antagonist is ________ _____
receptor blocker
Noncompetitive binding occurs when postsynaptic receptor sites have _____ binding site
more than one
In ___________ _______, molecules of the neurotransmitter bind with one site, and other substances bind with the others
noncompetitive binding