pharmacology: sedative-hypnotic-anxiolytic drugs

Question 1

what are the sedative-hypnotic-anxiolytic drugs?

Answer 1

benzodiazepines, barbiturates, alcohols

Question 2

what is the GABA binding site? benzo? barbiturate?

Answer 2

GABA: alpha

benzo: gamma
barbiturate: beta

Question 3

what are the increasing CNS effects of benzos/barbiturate/alcohols?

Answer 3

paradoxical disinhibition –> sedation–> anxiolysis –> anticonvulsant and muscle relaxing –> hypnosis –> anesthesia –> medullary depression –> coma/death

Question 4

how do benzo/barbiturates/alcohol cause paradoxical disinhibition (excitement, drunk)?

Answer 4

inhibiting an inhibitory neuron (causing excitation instead)

Question 5

GABA A activation causes

Answer 5

increased Cl- influx

Question 6

GABA B activation causes

Answer 6

increased K+ efflux

Question 7

benzodiazepine mechanism

Answer 7

potentiate GGABA, increased frequency of CL opening with NO GABA mimetic activity!

Question 8

what are the benzodiazepines?

Answer 8

alprazolam, diazepam, lorazepam, midazolam, temazepam, oxazepam

Question 9

which benzodiazepines have a short half life? implication/clinical use?

Answer 9

temazepam and oxazepam - used in sleep disorders

Question 10

which benzos have a long half life? implication/clinical use?

Answer 10

alprazolam, diazepam, lorazepam, midazolam

-used in anxiety

Question 11

which benzo is used in panic/phobias?

Answer 11

alprazolam

Question 12

which benzo is used in withdrawal states?

Answer 12

diazepam

Question 13

which benzo is used in status epilepticus?

Answer 13

lorazepam

Question 14

which benzo is used in anesthesia?

Answer 14

midazolam

Question 15

what is used in benzodiazepine overdose? mechanism?

Answer 15

BZ receptor antagonist flumazenil

Question 16

barbiturates mechanism

Answer 16

prolong GABA activity by increasing DURATION of Cl- channel opening and have GABA mimetic activity

Question 17

what are the barbiturates? uses?

Answer 17

phenobarbital for seizures (long acting)

thiopental for induction of anesthesia (short acting)

Question 18

what is the contraindication for barbiturates?

Answer 18

porphyrias - blocks enzyme used in heme synthesis D-ALA synthase (buildup of chemicals related to RBC proteins)

Question 19

withdrawal signs for BZs vs withdrawal signs of barbiturates and alcohol

Answer 19

BZs: rebound insomnia, anxiety, seizures when used as antiepileptic or high doses
Barbiturates/ethanol: anxiety, agitation, life-threatening seizures (delirium tremens with alcohol)

Question 20

drug interactions with GABA A drugs

Answer 20

1. additive with other CNS depressants such as anesthetics, antihistamines, opiates, beta blockers
2. barbiturates induce metabolism of most lipid-soluble drugs such as oral contraceptives, carbamazepine, phenytoin, warfarin

Question 21

what are the non-BZ drugs?

Answer 21

1. zolpidem and zaleplon (BZ1 receptor agonist instead of BZ2) - used in sleep disorders
2. buspirone (no effect on GABA - 5-HT1A partial agonist - used in anxiety disorders)

Question 22

what is used for generalized anxiety disorders?

Answer 22

buspirone!