Week 1 Flashcards
What is LD50
Dose at which 50% of the population found to be lethal
What is ED50
Dose at which 50% of the population found drug to be effective
What is the Therapeutic Index?
Difference between ED and LD 50
Margin of safety
Low TI - little margin for dosing, easier to overdose
High TI - large margin for dosing, difficult to harm patient
Peripheral Nervous System
Somatic (sensorimotor)
Autonomic (parasympathetic, sympathetic)
Sympathetic Nervous System
Arousal - fight, flight, fright
Parasympathetic Nervous System
Immune system, energy storage, digestion, growth
What does Pharmacokinetics mean?
What happens to the drug once it has entered the body
What makes properties of a drug easier to cross membrane?
Liphophilicity (soluble in fats)
What is the most convenient drug absorption method?
Enteral - safe, convenient
What is sublingual eneteral absorption good for?
High lipophilic drugs
How much of a drug bypasses the liver if rectal administration?
50%
What do capillary endothelial cells have?
Continuous tight junctions
What does neurotransmission mean?
Neurons chemically communicating with neurons
What can’t cross the BBB?
Proteins - large molecules
only lypothetic drugs can
What are the 2 types of glial cells?
Astrocytes and oligodendrites
What are the main types of brain cells?
Neurons
Glial Cells
Ependymal cells
Microglia
What does EPSP mean?
Excitartory post synaptic potenital
Action potential will work - release of neurotransmitter
What does IPSP mean?
Inhibiatory Post Synaptic Potential
Stops the affect of drug - stops neurotransmission
Where is the dendrite?
Postsynaptic
Action potential process
EPSP occurs- Sodium channels open
Depolaristation - Sodium influx
Re-polarisation - reversal sodium potassium pump
Hyperpolarisation - undershoos that occurs due to potatisum efflux before neurons stabilises
What does exocytosis mean?
Neurotransmitter release
How do neurotransmitters communicate with the next neuron?
Receptors
What is an agonist?
‘keys’ that ‘unlock’ the receptor door
Binds to recpetor and has an effect
What is an antagonist?
‘keys; that fit the lock but can’t open the door
Binds to the receptor but doesn’t have an effect/stops an effect
What does affinity mean?
The attraction that a drug has for a receptor site
What does efficacy mean?
The ability for a drug to induce a response once bound to the receptor site
What do agonists have?
Affinity and Efficacy
What do antagonists have?
Affinity but not efficacy
What does antagonism cause?
Negative drug interaction
The effect of one drug or neurotransmitter minimised or abolished by another
What happens with non-competitive antagonism?
Blocks occur IN neuron or cell, not at the receptor site
What are the 2 types of positive drug interactions?
Additive - double effect
Synergistic - One drug potentiates the effect of another
What does tachyphylaxis mean?
rapid desensitisation of receptors - drugs don’t work anymore
