Module 5 CNS drugs Flashcards
Use for benzodiazepines
sedatives, anxiolytics, anticonvulsants
general structure of benzodiazepine
central carboxamide group; 7 membered heterocyclic ring structure with a halogen or nitro group in 7th position (reacts with receptor)
effects of halogen in drugs
parent compound becomes more lipid soluble
where do benzodiazepines bind
GABA receptor
how do benzos work
bind to GABA, GABA receptor opens up allowing Cl- into the cell, influx of Cl- in the cell makes cell much more negative making depolarization much harder; this inhibits cell
allosteric site
not the active endogenous site of the receptor, rather adjacent to endogenous site which causes change or alteration of receptor and creats some type of effect
lipophilicity
the ability to which a drug is lipid soluble and determines how drugs react with CNS
factors in deciding which drug is best to administer
route of administration, onset of action, duration, and degree of hepatic metabolism
metabolism requirements
drugs become less lipophilic and more water-soluble
majority of benzodiazepine locations
CYP450 and liver
the more lipophilic a drug
the easier it crosses the membrane into the CNS; the longer metabolism will take
use for barbituates
currently used for alcohol withdrawal; used to be used for everything that benzodiazepines are now used for; also used in the cocktail of lethal injection
barbiturate dosage results
bind allosterically; low dose opens calcium channel for longer; large dose opens GABA without needing GABA present
barbiturate role with glutamate
can block glutamate receptor and decrease excitatory signal
baclofen
only drug that works on GABA-B receptor; used as antispasmodic and muscle relaxant
