Exam 1! Flashcards
Pharmacology
study of the actions of drugs and effects on living organisms
neuropharmacology
study of drug-induced changes in the nervous system
Psychopharmacology
emphasizes drug-induced changes in mood, thinking, and behavior
drug action
physical changes producedby a drug when it binds to a target site (e.g. enzyme) or neurotransmitter
drug effect
drug action alters physiological or psychological functions
specific drug effect
based on physical and biochemical interactions of a drug with a target site in living tissue
nonspecific drug effect ( kinda like side effects)
based on certain unique characterisitics of the individual (e.g. mood,expectations, perceptions, attitudes) may also be related to the drugs biological action
placebo
- can produce physiolgical change
- can produce both therapeutic and side effects
- belief in a drug may produce real physiological effects despite the lack of chemical activity
pharmokinetic
what the body does to a drug? (how does your body handle drugs over time)
- the dynamic factors that contribute to bioavailability
Bioavailability
amount of the drug in the blood that is free to bind at target sites
What organ metabolises (dreaks down) drugs?
liver!!
Pharmokinetic factors:
- routes of administration !!
- absorption and distribution !!
- binding
- inactivation
- excretion
Routes of administration
how quickly drug reaches target tissue
Routes of administration
- oral/rectal
- intravenous
- intraperitonal
- subcutaneous
- Intramuscular
- inhalation
Blood circulation
- deoxgenated = blue color flowing to lungs to absorb oxygen
- from lungs to heart
- oxygen- heme/iron = red color flowing to organs
first pass effect (first past metabolism)
is a phenomenon of drug metabolism whereby concentration of a drug specifically when administered orally is greatly reduced before it reaches the systemic circulation
Oral administration
- benefits: safe, self-administered, economical
- considerations: degradation by stomach acids and enzymes
- many factors can influence plasma concentrations (example: absorption and first pass metabolism)
absorption
movement of drug from site of administration to the blood circulation
Factors that CAN influence absorption:
- food in stomach
- type of food
- physical activity
- metabolism
First pass metabolism (his definition)
chemical alteration of a drug by the liver prior to reaching brain, heart
- other methods by-pass liver
rectal administration
- the drug aviods first pass metabolism depending on placement
- used in infants, those incapable of taking drugs
Intravenous injection (IV)
- pros: most RAPID and accurate method
- cons: rapid onset offers little time to correct on overdose or allergic reaction
- drug cannot be removed from body
Inhalation
- drug is absorbed very rapidly from the lungs
2. psychoactive drug effect is rapid (nicotine, THC in marijuana, crack cocaine)
intranasal administration
- local effects: such as reliving nasal congestion
- systemic effects - allergy relief
- by passes blood brain barrier: produces high brain concentrations
- full absorption can occur in 15 mins!
important factor in determining plasma drug:
the rate of passage through cell membrane
passive diffusion
- means by which lipid soluble drugs can pass through the cell membrane
- movement is in direction from high to low concentration
- the larger the concentration gradient, the faster the diffusion
Other factors that affect absorption and distrubution:
- rate stomach empties
- size and sex of individual
- frequency and history of prior drug use
- blood brain barrier
Blood brain barrier
barrier around blood supply that prevents potential toxins from getting out of blood stream into central nervous system
teratogens
is any agent that causes an abnormality following fetal exposure during pregnancy.
drug depot
a drug can get absorbed where we do not want it to get absorbed
Drug depots
- binding can occur at inactive sites
- can include proteins in blood supply, muscle, and HAIR AND LIPIDS
- depot binding prevents drug from reaching its target
half life
time it takes for 50% of the drug in blood supply to be metabolize (broken down by liver)
99% of drugs are metabolized by liver
first order kinetics
drugs are eliminated vis biotransformation (metabolism) and metabolizes are excreted
excertion
biotransformation
the alteration of a substance within the body
zero order kinetics
molecules are cleared at a constant rate regardless of concentration
enzyme induction
repeated use of drugs increases # of enzymes and speeds metabolism
drug tolerance and cross tolerance
drugs lose effectiveness with repeated use
pharmodynamics
physiological and biochemical interaction of drug molecules with cell receptors in target tissue
- how drugs alter the body
receptors
proteins in the bi-lipid plasma membrane
ligand
molecule that binds to a receptor with some selectivity
molecular docking
a computational elimination of 3 dimensional interactions and receptor
efficacy
desired effect that a drug can produce regardless of dose
potentcy
amount of a drug that is needed to produce the desired effect
agonist
binds to receptor and activates it to produce biological response
antagonist
blocks the activity of any receptor
partial agonist
binds to sit, activates it, but produces an effect that is lessen then endogenous ligand or a full agonist
- chantix
competitive antagonist
bind to same site on receptor as agonist, but blocks agonist
-inhibition can be overcame by increasing agonist
noncompetitive antagonist
bind to a different site on a neuron than an agonist (any where but the receptor site)
- inhibition cannot be overcome by increasing concentration of agonist
