Chapter 4 Flashcards
Properties of Drug
DEFINE
What are the 4 steps in Pharmacokinetics?
- Absorption
- Distribution
- Biotransformation
- Elimination
EXPLAIN
What is occuring in the absorption step of Pharmacokinetics?
Drug is administered and is absorbed into the blood stream
EXPLAIN
What is occuring in the Distribution step of Pharmacokinetics?
Drug is passed through the bloodstream and into the organs, penetrating the membrane
EXPLAIN
What is occuring in the Biotransformation step of Pharmacokinetics?
The drug is broken down into metabolites by enzymes
EXPLAIN
What is occuring in the Elimination step of Pharmacokinetics?
The drug and/or metabolites are eliminated from the body
LIST
What are the 8 routes of administration?
- Inhalation
- Intramuscular
- Intravenous
- Oral
- Nasal and Mucosal membrane
- Subcutaneous (into the fatty tissue)
- Sublingual
- Transdermal (absorbed through an external patch)
EXPLAIN
What does the Henderson-Hassleback Equation calculate?
The ratio of unionized to neutral drug molecules in a drug
EXPLAIN
If a drug has a pKa close to the local pH, will it have more neutral or ionized molecules than those with a pKa further than from the local pH?
it will be more neutral
DEFINE
Liberation
in the drug processing
The process of drug molecules seperating from the delivering form
want drugs to absorb in intestines
DEFINE
Distribution
The passage of a drug from the bloodstream to sites in the body
DEFINE
Bioavailability
The ability of a drug to reach a site of action
DEFINE
Nonspecific Binding
The binding of a drug to site thats are not the intended target
* protein binding
* Depot binding
DEFINE
What is the Blood-brain Barrier?
The barrier that surrounds the blood vessels in the brain to prevent substances in the blood from entering the brain
DEFINE
What is passive diffusion?
The diffusion of molecules across the Blood-Brain Barrier
LIST
What are the 3 requirements for being able to do passive diffusion?
- Lipid/Fat soluble
- Neutral charge
- Small
DEFINE
Active Transport
The use of membran channels or transporters that allow the passage of chemicals
DEFINE
Biotransformation
The conversion of a drug into one or more metabolites
EXPLAIN
How many phases are there in biotransformation?
2
EXPLAIN
What happens in phase 1 of biotransformation?
- CYP450 family of enzymes
- Usually generates atleast 1 water soluble motabolites
EXPLAIN
What happens in phase 2 of biotransformation?
- Catabolism via conjugation
- Become bigger, charged as less lipid soluble
conjugation: transfer of genetic material between bacterial cells
DEFINE
First-Pass metabolism
Metabolism that occurs before a drug enters circulation
DEFINE
Active Metabolite
A drug’s metabolite that has its own physiological effect
DEFINE
Prodrug
A physiologically weak or inactive compounds metabolized in the body to produce an active drug
DEFINE
Elimination Rate
An amount of drug eliminated from the body over time
LIST
What are the 2 types of elimination?
- Zero-Order Kinetics (Constant)
- First-Order Kinetics (Non-Constant/Half life)
DEFINE
Steady-State Drug Concentration
A sustained concentration of a drug in the body over multiple doses
Slow release formulation using its half life
DEFINE
Binding Affinity
How well a drug binds to its receptor
DEFINE
Receptor Efficacy
The effect a drug has on its receptor
LIST
What are the 3 types of Receptor Efficacy?
- Agonist
- Partial Agonist
- Antagonist
- Inverse Agonist
DEFINE
Agonist
Receptor Efficacy
The drug activiates the neurotransmitter receptor as expected
DEFINE
Antagonist
Receptor Efficacy
The drug fails to activate a receptor and prevents another neurotransmitter from activating the receptor
* Competitive: Prevents NT binding
* Noncompetitive: Does not prevent binding; still cannot activate
DEFINE
Partial Agonist
Receptor Efficacy
The drug has a weaker efficacy for activating receptors
DEFINE
Allosteric Binding Site
A binding site on a receptor that is different than where the neurotransmitter binds
LIST
What are the 5 types of drug tolerances?
- Pharmacokinetics
- Pharmacodynamic
- Behavioural
- Conditioned
- Cross
DEFINE
Pharmacokinetic Tolerence
Reduces the amount of drug reaching the target organ
DEFINE
Pharmacodynamic Tolerance
Reduces the responsiveness of target organ to the drug
DEFINE
Behavioural Tolerance
Reduced drug effect from learned behaviour and enviromental cues
DEFINE
Conditioned Tolerance
Conditioned physiological responses counteract the drugs effects
DEFINE
Cross Tolerance
The frequent use of one drug that leads to a tolerance for other drugs with similar biological functions
DEFINE
Withdrawal Syndrome
A collection of responses that occur when a drug is no longer administered
Both physical and psychological
