principles of neuropharmacology Flashcards
what is pharmacology?
drug action and effect
what is psychopharmacology?
drug-induced changes in mood, thinking and behaviour
what is neuropharmacology?
drug-induced changes in brain functioning
what is neuropsychopharmacology?
identify substances acting upon the nervous system to alter disturbed behaviour
psychoactive drugs
change brain function to alter mood, perception and behaviour
therapeutic effect
desired physical or behavioral change
side effect
anything outside of the desired effects
specific effect
caused by drug-receptor interactions
nonspecific effect
based on individual characteristics
- experience, mood, expectations, attitude, genetics
pharmacokinetics (PK)
the study of how drugs move through the body
oral advantages
- safest, most convenient and economical
- self administered
oral administration
taken via mouth
oral disadvantages
- least efficient
- stomach acids destroy drugs fast
- individual differences make it hard to know how much of the drug will be absorbed into the blood
intravenous (IV)
injecting drug directly into the venous blood stream
IV advantages
- doses extremely precise
- extremely fast onset of pharmacological action
- less strain on liver
IV disadvantages
- extremely dangerous
- very few barriers between drug and brain
- very little time for intervention
- requires a health care professional for administration
intramuscular (IM)
directly into skeletal muscle tissue
IM advantages
- faster than oral but slower than IV
- absorption is more gradual
- can be combined with other drugs like oil to control absorption
IM disadvantages
- rate of absorption depends on rate of blood flow to that muscle
- it hurts
subcutaneous (SQ)
under the skin
SQ advantages
slow and steady
SQ disadvantages
depends on derma layers, fat layers, blood flow to the area
dura mater
- layer of meninges
- a thick, tough, protective membrane made of connective tissue that covers the brain and spinal cord
epidural
injection mute afferent sensory communication (ex. can’t feel pain)
inhalation
inhaled drugs and oxygen enter the bloodstream via lung capillaries and travel directly to the brain
sublingual and intranasal
absorption via mucus membrane of nose and mouth gains access to the bloodstream
transdermal
patches provide a slow, continuous and highly controlled release of a drug
factors that influence how we absorb drugs
- transport across membranes
- lipid (in)solubility
- ionization of drugs
- genetic differences at every step along the way
- current metabolic and homeostatic state
capillaries
small blood vessels that are the site of exchange of many substances between the arterioles and venules
blood-brain barrier
a highly-selective semipermeable membrane that separates circulating blood from brain
passive diffusion
substances cross the membrane without the input of energy
metabolism
the chemical alterations of drugs that reduce the effects of the drugs and increase their likelihood of excretion
enzyme induction
repeated use of a drug increases the number of enzymes capable of breaking the drug down
phase I metabolism
less reactive compound is converted to a more reactive molecule through oxidation, reduction or hydrolysis
phase II metabolism
active or toxic molecules are converted to a less active metabolite
kidney elimination
excrete water-soluble drugs and metabolites in the urine
live elimination
bile excretes some drug molecules in feces
exhalation
through the lungs or escape via sweat pores
pharmacodynamics
the study of the physiological and biochemical interaction of drug molecules with cell receptors in their target tissue
receptors
proteins on cell surfaces or within cells
ligand
molecule that binds to a receptor with some selectivity
agonist
produces biological effect
antagonist
produces no cellular effect
affinity
the strength of the attraction between a ligand and a receptor
potency
absolute amount of drug needed to produce a specific effect
ED-50
the amount of drug that produces the desired effect in 50% of patients
TD-50
the dose at which a drug will be toxic to 50% of patients
therapeutic index
TI= TD-50/ED-50
