Barbiturates Flashcards Preview

ANPH 500 - Pharmacology - McCarver > Barbiturates > Flashcards

Flashcards in Barbiturates Deck (50)
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0
Q

Any drug derived from __ acid = a barb

A

Barbituric acid

1
Q

Why have barbs fallen out of favor?

A

Hangover effect- residual drowsiness lasting many hours

2
Q

Barbs are __ salts and are __ soluble in IV fluids

A

Sodium salts

Highly soluble

3
Q

Because they are highly alkaline, they easily __ with opioids, catecholamines, and NMB

A

Precipitate

4
Q

Barbs are only available as a __ % solution due to caustic to vessels

A

2.5%

5
Q

Substitutions at 2 and 5 carbons gives different effects.

Sulfur at 2 and 5-

A

Sulfur at 2 and 5- increase lipid solubility

6
Q

Substitutions at 2 and 5 carbons gives different effects.

Phenyl at 2 and 5-

A

Anti-convulsant

7
Q

Substitutions at 2 and 5 carbons gives different effects.

Methyl group at 2 and 5-

A

Convulsive activity

8
Q

Prompt awakening from barbs is due to

A

Redistribution

Test question

9
Q

What ion is associated with GABA receptors?

A

Chloride

Test question

10
Q

Barbs have a unique ability to depress BOTH __ and __

A

Reticular activating system

SNS ganglia- leading to hypotension

11
Q

Non ionized fraction exerts pharm effect

A

Test question

12
Q

Patients on highly protein bound meds such as __ and __ increase barb effects

A

ASA

phenytoin

13
Q

Patients with cirrhosis and neonates have __ sensitivity to barbs

A

Greater

14
Q

Maximum brain uptake in __ seconds for thiopental and methohexital

A

30

15
Q

Initial decreases in plasma concentrations of barbs are due to redistribution to __

A

Skeletal muscle

16
Q

Barb levels continue to rise in __ 30 minutes post injection

A

Fat

17
Q

Calculate induction drugs using __ body weight

A

Lean

18
Q

Acidosis __ barb effects

A

Increases

19
Q

Alkalosis __ barb effects

A

Decreases

Due to alterations in the non-ionized fractions

20
Q

Cardiopulmonary bypass __ systemic clearance of barbs

A

Decreases

21
Q

Oxi-barbiturates are metabolized __

A

Hepatic only

22
Q

Thio-barbs (with the sulfur) metabolize

A

Mainly hepatic but also kidneys and CNS

23
Q

Barb metabolism is __.

A

Slow

24
Q

Enzyme induction may __ the dose requirements but does not modify the duration of action.

A

Increase

25
Q

Do roach of the liver patients have any difference in barb clearance?

A

No

26
Q

Methohexital hepatic clearance is __x greater than thiopental, therefore it has the least hangover

A

4x

27
Q

While redistribution determines awakening, __ determines complete recovery.

A

Metabolism

28
Q

Old age __ anesthetic effects of barbs

A

Increases

29
Q

Peds patients recover __ due to more rapid hepatic clearance

A

Quicker

30
Q

Barbs are cerebral vaso__

A

Constrictors

31
Q

Barbs __ provide sedation in the presence of pain, they actually can lower the pain threshold.

A

Cannot

32
Q

Barbs have __ skeletal muscle relaxation

A

No

33
Q

Methohexital has __ risk of excitatory phenomena like hiccups and myoclonus, which are dose related.

A

Increased

34
Q

Thiopental induction dose

A

3-5 mg/kg

This is how I remember it, since it clears 4x slower than metho, give 4 mg/kg

35
Q

Methohexital induction dose

A

1-1.5 mg/kg

Same as succs

36
Q

Lower BP with barbs due to peripheral __ due to depressed medullary vasomotor centers, decreased SNS outflow

A

Peripheral vasodilation

37
Q

Hypovolemic patients are extremely vulnerable to marked decreases in BP from barbs, so __

A

Don’t use barbs with hypovolemic peeps

38
Q

Barbs- give ‘em __

A

Quick

39
Q

Barbs depress ventilation and __ sensitivity to high CO2, but do not depress laryngeal or cough reflexes

A

Decrease

40
Q

Barbs an evoked potentials?

A

No interference

41
Q

Barbs __ enzymes to a max of doubling metabolism rates

A

Induce

42
Q

Barb-related enzyme induction results in increased metabolism of other drugs like __

A
Coumadin
Phenytoin
Tricyclics
Corticosteroids
Vit K
43
Q

Barbs are contraindicated with __ patients due to stimulation of heme production

A

Porphyria

44
Q

Should you give barbs intra-arterial?

A

No

Immediate vasoconstriction and excruciating pain, gangrene, precipitation of crystals leading to arteritis.

45
Q

What barb induces enzymes the most?

A

Phenobarbital

46
Q

Venous thrombosis after barb admin due to __

A

Deposition of barb crystals

47
Q

Barb thera index __ with tolerance.

A

Decreases

48
Q

Allergic reaction to Thio around 1:__,000 , seen more often with prior Thio exposure or chronic atopy, meaning IgE hypersensitivity such as __

A

1:30,000

Hay fever
Asthma
Infantile eczema
Urticaria
Food reactions
49
Q

Thio mixtures are highly __

A

Bactericidal