Sedative & Hypnotics

Question 1

What are the 5 main types of CNS depressants?

Answer 1

Alcohol
General anesthetics
Barbiturates
Non - barbiturates
Benzodiazepines

Question 2

Is ethanol a general CNS depressant w/ full spectrum?

Answer 2

Yes
-> from anti - anxiety to anesthesia / death

Question 3

Where is ethanol absorbed?

Answer 3

Stomach
Intestine

Question 4

Why is ethanol used to treat methanol intoxicated?

Answer 4

Compete with methanol for the enzyme
-> Alcohol dehydrogenase

Diuretic
-> promotes excretion of methanol

Question 5

What are the mechanism of Disulfiram that allows it to be used as treat chronic alcoholism?

Answer 5

Disulfiram inhibits aldehyde dehydrogenase
-> increased acetaldehyde conc.
–> causes Acetaldehyde syndrome
—> extremely uncomfortable

Question 6

Is thio - barbiturates longer acting than oxy - barbiturates in general?

Answer 6

No
Generally
-> oxy - barbiturates is longer acting than thio - barbiturates

Question 7

If oxy - barbiturates is longer acting than thio - barbiturates, does that mean thiopental is shorter acting than methohexital?

Answer 7

No
-> Methohexital is kind of an exception

Question 8

Provide 1 example of barbiturates with ultra short lasting, short lasting and long lasting effects

Answer 8

Ultra short lasting
-> Thiopental

Short lasting
-> Pentobarbital

Long lasting
-> Phenobarbital

Question 9

What is the main function of Thiopental?

Answer 9

Anesthesia

Question 10

What is the main function(s) of Pentobarbital?

Answer 10

Anesthetics
Hypnotic
Anticonvulsant

Question 11

What is the main function(s) of Phenobarbital?

Answer 11

Anticonvulsant

Question 12

What is the main neurotransmitter(s) for Presynaptic inhibition?

Answer 12

GABA
-> gamma - aminobutyric acid
–> (G)amma - (A)mino(B)utyric (A)cid

Question 13

What is the main neurotransmitter(s) for Postsynaptic inhibition?

Answer 13

Glycine
Opioids
GABA

Question 14

What type of channel is GABA(A) receptor?

Answer 14

Ligand - gated Cl- channel

Question 15

How many subunits does GABA(A) receptor have?
What are they?
What could bind to it?

Answer 15

5 subunits
-> Alpha x 2
–> binding of GABA molecules for activation

-> Beta x 2
–> binding of Barbiturate

-> Gamma x 1
–> binding of Benzodiazepine

Question 16

What happens when Barbiturate binds GABA(A) receptor?

Answer 16

Increases [Open time] of Cl- channel
High doses
-> directly activate GABA(A)
–> w/ or w/o GABA molecule on Alpha binding site for activation
—> causes CNS depression / death

Question 17

What happens when Benzodiazepine binds to GABA(A) receptor?

Answer 17

Increases [Open frequency] of Cl- channel
Always requires GABA activation
-> does not cause severe CNS depression

Question 18

Is barbiturate a full spectrum drug?

Answer 18

Yes

Question 19

What is Therapeutic Index?

Answer 19

Ratio of
-> dose of a drug that produces a therapeutic effect
-> dose of a drug that produces toxicity

Equation
Median Lethal dose (LD50)
Therapeutic Index (TI) = —————————————–
Median Effective dose (ED50)

The lower the TI, the harder it is to grasp the amount of drugs needed to produce a therapeutic effect w/o causing toxicity

Question 20

Can phenobarbital be administered orally and still be well absorbed?

Answer 20

Yes

Question 21

What are the 3 main clinical uses of Barbiturates?

Answer 21

Anesthesia
Anticonvulsant
Euthanasia ( Small lab animals )

Question 22

Is Barbiturate IV anesthesia used for induction or maintenance, or both?

Answer 22

Induction only

Question 23

Can barbiturate used for pain control?

Answer 23

Nope
-> not analgesic

Question 24

How is Chloral hydrate administered?

Answer 24

IV
PO

Question 25

What is chloral hydrate mainly used for for large animals? and why?

Answer 25

Pre med -> reduce dosage needed for anesthesia -> smoother induction of general anesthesia

Question 26

Is Benzodiazepine full spectrum?

Answer 26

Nope -> non anesthetic -> at most hypnotic only

Question 27

Does BZD or barbiturate has less acute toxicity?

Answer 27

BZD has way less acute toxicity -> LD50 --> Diazepam > Pentobarbital

Question 28

Which of the following means the same as " Major tranquilizer " a) Neuroleptics b) Antipsychotics c) Antischizophrenics d) Benzodiazepine

Answer 28

a) Neuroleptics b) Antipsychotics c) Antischizophrenics

Question 29

Which of the following are clinical uses of BZD? a) Insomnia b) Anxiety disorder c) Skeletal muscle relaxation d) Alcohol withdrawal e) Anticonvulsant f) Pre med

Answer 29

All

Question 30

Is Diazepam long - acting, intermediate - acting or short - acting?

Answer 30

Long - acting

Question 31

What effects does it have in dogs & cats and are therefore used as behavior modification drugs?

Answer 31

Anxiolytic effects

Question 32

Can both BZD and barbiturate cause addiction?

Answer 32

Yes

Question 33

At hypnotic doses, does BZD affect respiration?

Answer 33

No

Question 34

Can pregnancy exposure to BZD cause prenatal toxicity?

Answer 34

Yes

Question 35

What happens to da babi if early pregnancy exposure to BZD in rodents?

Answer 35

Teratogenesis

Question 36

What happens to da babi if late pregnancy exposure to BZD in women?

Answer 36

Floppy baby syndrome

Question 37

Could diazepam cause serious hepatic necrosis in dogs due to toxic intermediate metabolites called nordiazepam?

Answer 37

No -> cats though yes

Question 38

What are 3 examples of other drugs whose CNS depressant effect can be potentiated by BZD?

Answer 38

Barbiturates Ethanol Ketamine

Question 39

What are 4 difference between BZD and barbiturate?

Answer 39

1. In terms of development of tolerance and addiction -> Barbiturate > BZD 2. Barbiturate induces significant drug - drug interaction -> Cytochrome P450 induction 3. Barbiturate could produce life - threatening withdrawal reactions -> regular use could lead to dependence 4. In terms of pharmacological effects on CNS depression -> Barbiturate = full spectrum --> could cause death -> BZD --> hypnosis at most

Question 40

Is 'BZD' or 'barbiturate' in general a safer drug? And if so, in what occasion would we use the non safer drug?

Answer 40

BZD is generally a safer drug Barbiturate is still used -> Short - acting barbiturate --> Anesthesia -> Long - acting barbiturate --> Anticonvulsant

Question 41

What is the BZD antagonist? And its mechanism?

Answer 41

Flumazenil -> competes for GABA(A) receptor --> but no intrinsic efficacy ---> meaning it does not produce a pharmacological effect when bound to the receptor

Question 42

What is the non BZD anxiolytic drug that falls under the category of Azapirones? And its mechanism?

Answer 42

Buspirone -> Partial agonist 5-HT(1A) receptor --> No side ( adverse ) effects at all