Flashcards in Transmitters and Receptors Deck (32):
5 places that CNS drugs can act on
4. Inactivation: Re-uptake/Metabolism
Problems with drug in the CNS re: mechanisms:
molecular mechanisms known
therapeutic mechanism not always known.
SSRI, Cocaine and Anti-AChE affect what?
reuptake of NTs
Cocaine and amphetamines affect NA but also:
Which drug in epilepsy limits excitatory nerve activation?
phenytoin: binds to OPEN sodium channel, decrease Glutamate action
What drug enhances inhibitory input for epilepsy?
benzodiazepines enhance GABA receptor activity
Two NTs implicated for sedation/anxiety?
3 NTs implicated for anxiety?
NT implicated for Sedation in children
Benzodiazepines used in treating what 5 main things:
acute alcohol withdrawal
Beta-adrenoceptor antagonists do what for anxiety?
block physical signs
nothing for CNS though
4 clinically recognized anxiety disorders?
Barbiturates, hypnotic/anxiolytics used much today?
pretty much obsolete
What is Zolpidem?
direct non-benzodiazepine GABA agonist at orthosteric site
What do barbiturates do? why bad?
toxic: narrow therapeutic window
induce liver enzymes
abrupt withdrawal = death
2 situations where you anxiolytics/hypnotics are still used?
Why choose benzodiazepines over barbiturates?
wider therapeutic index
less cardioresp depression
'safer' in overdose
benzodiazepines interact with GABA A or GABA B receptors?
GABA A receptor only
three ways benzodiazepines interact with GABA A receptor?
1. modulate orthosteric ligand affinity
2. modulate orthosteric ligand efficacy
3. modulate receptor activation level
benzodiazepines modulate at which site?
diazepam a benzodiazepines does what to the GABA A receptor?
1. increase frequency of Cl- channel opening
2. increase sensitivity with no change to maximal response
difference between benzodiazepines and barbituates in terms of receptor channel? how does this affect overdose?
1. benzodiazepines: open and close/frequency: hits ceiling, safer
2. barbituates: keeps the channel open, can overdose easily
why are allosteric modulators better?3 big ones:
1. increase therapeutic window
2. positive modulation of ENDOGENOUS agonist, not exogenous
3. more receptor subtype selectivity
unwanted side effects of benzodiazepines?
disadvantages of benzodiazepines?
interact with alcohol,
Can you take the same dose of benzodiazepines always?
develop tolerance: need to increase dose
How long is short vs. long acting benzodiazepines?
short: 6-12 hours
Long: >24 hours
Does low potency matter?
only if awkward to administer, low potency does not = inferior drugs
what is pharmacological efficacy?
strength of receptor activation: full vs. partial agonist
what is clinical efficacy?
strength of beneficial effect
benzodiazepines vs. barbituates: 3 big points in terms of efficacy/potency
1. both affect GABA receptors
2. Benzo: increase channel frequency (increase potency)
3. barbituates increase duration of Cl- channel opening (increase efficacy)