Induction Agents - Barbiturates

Question 1

What is the typical IV induction dose of thiopental in adults?

Answer 1

3–5 mg/kg

This dosage is standard for inducing anesthesia in adult patients.

Question 2

What is the onset time of action for thiopental when administered IV?

Answer 2

30–60 seconds

This rapid onset is critical for induction of anesthesia.

Question 3

How long do the clinical effects of a single IV dose of thiopental typically last?

Answer 3

5–10 minutes

The short duration is due to rapid redistribution.

Question 4

Thiopental’s primary mechanism of action is:

Answer 4

Enhancement of GABA-A receptor activity

This leads to central nervous system depression.

Question 5

Which of the following is a key side effect of thiopental?

Answer 5

Laryngospasm

This side effect can complicate airway management.

Question 6

Which patient condition is contraindicated for thiopental use?

Answer 6

Porphyria

Thiopental can trigger acute attacks in affected patients.

Question 7

Thiopental is particularly useful in:

Answer 7

Induction in patients with increased intracranial pressure, neuroprotective, decreases CBF and CBV

Its properties make it suitable for neurosurgical procedures.

Question 8

Is Thiopental a barbiturate used for induction of anesthesia?

Answer 8

Yes

It is commonly utilized in anesthetic practice.

Question 9

Does thiopental provide good muscle relaxation and analgesia?

Answer 9

No

It lacks analgesic properties.

Question 10

Does Thiopental cause dose-dependent respiratory and cardiovascular depression?

Answer 10

Yes

Monitoring is essential during administration.

Question 11

Is Thiopental contraindicated in patients with acute intermittent porphyria?

Answer 11

Yes

This is due to its potential to worsen porphyrin metabolism.

Question 12

Do the effects of thiopental wear off quickly due to rapid metabolism?

Answer 12

No

Initial recovery is primarily due to redistribution.

Question 13

Can Thiopental be used for seizure control?

Answer 13

Yes

It is effective in managing certain seizure types.

Question 14

Does Thiopental produce an increase in intracranial pressure?

Answer 14

No

It actually helps to decrease intracranial pressure.

Question 15

What is the induction dose of thiopental for adults?

Answer 15

Typically 3–5 mg/kg IV

This is the standard dosing for inducing anesthesia.

Question 16

How quickly does thiopental take effect after IV administration?

Answer 16

30–60 seconds

This rapid effect is crucial for anesthesia induction.

Question 17

Why does the clinical effect of thiopental wear off after just a few minutes?

Answer 17

Because of redistribution from the brain to peripheral tissues

This pharmacokinetic property leads to quick recovery.

Question 18

What is the mechanism of action of thiopental?

Answer 18

Enhancement of GABA-A receptor activity leading to CNS depression, also depresses reticular activation system (RAS)

This results in sedation and loss of consciousness.

Question 19

Name two common side effects of thiopental.

Answer 19

Respiratory depression, hypotension, laryngospasm

These side effects require careful monitoring.

Question 20

In what situation is thiopental especially useful due to its cerebral protective effects?

Answer 20

In patients with elevated intracranial pressure or during neurosurgery

Its neuroprotective properties make it favorable in these scenarios.

Question 21

Why is thiopental contraindicated in porphyria?

Answer 21

It induces hepatic enzymes that worsen porphyrin metabolism, triggering acute attacks

This can lead to serious complications.

Question 22

Does thiopental provide analgesia?

Answer 22

No, it does not have analgesic properties

It is primarily a sedative agent.

Question 23

What property of thiopental makes it suitable for rapid sequence induction?

Answer 23

Rapid onset and short duration of action

These characteristics are ideal for emergency scenarios.

Question 24

What is the typical IV induction dose of methohexital in adults?

Answer 24

50-120 mg

This dosage is used for induction in various procedures.

Question 25

What is the usual onset of action for methohexital after IV administration?

Answer 25

10–30 seconds ## Footnote This rapid onset is beneficial for procedural sedation.

Question 26

What is the typical duration of action for a single IV dose of methohexital?

Answer 26

5–7 minutes ## Footnote This short duration is useful in specific clinical settings.

Question 27

What is the mechanism of action of methohexital?

Answer 27

GABA-A receptor agonist ## Footnote This enhances GABAergic activity in the CNS.

Question 28

Which of the following is a known clinical effect of methohexital?

Answer 28

Sedation and hypnosis ## Footnote It is primarily used for its hypnotic properties.

Question 29

Which of the following procedures is methohexital commonly used for?

Answer 29

Procedural sedation for electroconvulsive therapy (ECT), doesn’t lower seizure threshold ## Footnote Its unique properties make it suitable for ECT.

Question 30

Which of the following is a side effect associated with methohexital?

Answer 30

Seizure-like myoclonic movements ## Footnote These movements may occur during administration.

Question 31

Is Methohexital classified as an ultra-short-acting barbiturate?

Answer 31

Yes ## Footnote This classification indicates its rapid onset and short duration.

Question 32

Does Methohexital have strong analgesic properties?

Answer 32

No ## Footnote It is not effective for pain management.

Question 33

Do the hypnotic effects of methohexital wear off quickly due to redistribution?

Answer 33

Yes ## Footnote This property facilitates rapid recovery from sedation.

Question 34

Can Methohexital cause excitatory phenomena such as hiccups and myoclonus?

Answer 34

Yes ## Footnote These side effects are noted during its use.

Question 35

Is Methohexital safe for use in patients with a history of porphyria?

Answer 35

No ## Footnote It can precipitate acute porphyric crises.

Question 36

Does Methohexital increase seizure threshold, making it ideal for seizure suppression?

Answer 36

No ## Footnote In fact, it lowers the seizure threshold.

Question 37

Is respiratory depression a potential risk with methohexital administration?

Answer 37

Yes ## Footnote Monitoring is crucial to manage this risk.

Question 38

What is the typical induction dose of methohexital for adults?

Answer 38

1–2 mg/kg IV (50-120 mg) ## Footnote This dosage is used for various procedures requiring sedation.

Question 39

What is the onset time for methohexital when administered intravenously?

Answer 39

10–30 seconds ## Footnote This rapid onset is advantageous for procedural sedation.

Question 40

How long does a single IV dose of methohexital typically last?

Answer 40

Approximately 5–7 minutes ## Footnote This allows for quick recovery post-sedation.

Question 41

What receptor system does methohexital primarily act on?

Answer 41

GABA-A receptors (enhances GABA activity) ## Footnote This mechanism is key to its sedative effects.

Question 42

List two side effects commonly associated with methohexital.

Answer 42

Myoclonic movements, respiratory depression, laryngospasm ## Footnote These side effects necessitate careful patient monitoring.

Question 43

In what scenario is methohexital especially preferred over other agents?

Answer 43

During electroconvulsive therapy (ECT) ## Footnote Its properties make it particularly suited for this procedure.

Question 44

Why should methohexital be avoided in patients with porphyria?

Answer 44

It can precipitate an acute porphyric crisis due to enzyme induction ## Footnote This is a critical consideration in patient safety.

Question 45

Does methohexital provide muscle relaxation or analgesia?

Answer 45

No, it provides sedation/hypnosis but lacks muscle relaxation and analgesia ## Footnote It is not suitable for procedures requiring pain control.