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Psychopharm Neuro
Psychopharmacology (UNIT 4)
Question | Answer |
---|---|
Psychopharmacology | study of the effects of drugs on the nervous system and behavior |
What is a drug? | Exogenous/ not necessary for normal function/ alters the functions of cells in low amnts |
A drug must | Have an effect (s)/ Have a site (s) of action |
Pharmacokinetics | time course and movement of a drug |
Processes of pharmacokinetics | Absorption/Distribution/Metabolism/ Elimination |
oral admin | primary/ 1st gastrointestinal(liver before blood)upper int by passive diffusion/lipid solubility (membranes) |
psychoactive drugs | weak acids/very lipid sol/ absorbed quickly/trapped in blood plasma/75 percent in 3 hrs/ less control |
inhalation | recreation/quick/lungs are richly vascularized/straight to the brain/ |
mucous membranes (nose and mouth) | cocaine |
injections | iv/im/sc |
iv | directly to brain/good control of speed,volume, concentration/dangerous |
im | absorbed quickly in muscles |
sc | rapid/ can cause irritation |
distribution | circ system quickly |
total blood volume | is circulated every minute |
side effects | only a small amnt is in contact with receptors |
drug also binds to | protein (less effective) & fat (long-term storage) |
capillary walls | drug leaves through tiny pores |
BBB | no pores/lipid sol |
placental membrane | lipid sol cross easily |
different membrane | different lipid solubility |
one membrane | neuron/ mitochondria |
several layers | skin/ vagina/placenta |
single layer | intestines |
selective permeability det by | diffusion/ pH/ chem comp of drug/ size |
metabolism | in the liver |
metabolites | less lipid sol/ stay in bloodstream |
cytochrome p | enzyme family involved in drug metabolism (12) |
changes in activity of cyps | some drugs inactivate/grapefruit juice |
alcohol | does not have a half-life/ straight line down |
elimination | kidney/ drug becomes more water sol as metabolized/ trapped in kidney and passed |
pharmacodynamics | molecular (receptor) |
receptor specificity | best chemical fit/ influences effectiveness |
dose-response curve | s- shape |
potency | amnt needed for effect |
efficacy | max effect attainable |
variability | ind diff |
ED-50 | half of subjects see effect |
LD-50 | half of subjects die |
margin of safety | LD 50 minus ED 50 |
therapeutic index | ratio of ED 50 to LD 50 |
higher index | safer drug |
why drugs vary in effectiveness | diff sites if action/ diff affinities for rec |
alcohol and benzo or mari | very depressant |
alcohol and other drugs | alcohol opens BBB/ aspartame =neurotoxin |
alcohol and cocaine | increased half-life |
alcohol and sex | increases risky behavior/ unwanted pregnancy |
drug toxicity | allergies/ liver enzymes/kidney damage |