Intravenous GAs

Question 1

What are the Intravenous GAs?

Answer 1

Methohexital, 
Ketamine, 
Etomidate, 
Propofol
 Fospropofol

Question 2

What are intravenous GAs used for?

Answer 2

Used for INDUCTION of anesthesia
Used to reduce the amount of inhalation
anesthetics (BALANCED ANESTHESIA)

Question 3

What is the Pharnokenitics and advantages of intravenous GAs?

Answer 3

PK: RAPID ONSET and SHORT Half-life;
Recovery due to REDISTRIBUTION

Advantage: LESS CARDIOVASCULAR
DEPRESSION than inhalation anesthetics

Question 4

What is the MOA, Clinical use, Adverse effects and PK and clinical use of Methohexital?

Answer 4

MOA: ENHANCES INHIBITION by binding to GABAA receptor complex

Clinical Use: Outpatient Surgery (replaced by Propofol)

Adverse Effects:

 - HYPERALGESIA 
 - Tachycardia, sweating

PK: Ultra-SHORT acting barbiturate

Question 5

What is the ketamine a derivative of?

Answer 5

Derivative of hallucinogen phenylcyclidine (PCP)

Question 6

What is MOA, clinical use and adverse effects of ketamine?

Answer 6

MOA: REDUCES EXCITATION by BLOCKING GLUTAMATE RECEPTORS (i.e, NMDA)

DISSOCIATIVE ANESTHETIC — catatonia, analgesia and amnesia W/O LOSS OF CONSCIOUSNESS

Clinical Use: Diagnostic and minor surgical procedures (non-sk muscle relaxation)

MOA: REDUCES EXCITATION by BLOCKING GLUTAMATE RECEPTORS (i.e, NMDA)

Adverse Effects: Dilates cerebral vessels (increases ICP), increases catecholamine release — CAUTION: CARDIOVASCULAR DISORDERS

Question 7

What is the MOA Clinical use adverse effects & PK of Etomidate?

Answer 7

MOA: ENHANCES INHIBITION by binding to GABAA receptor complex

Clinical Use: Surgery on patients with cardiovascular disease (minimal effect on cardiovascular and respiratory system)

Adverse Effects: POST-OP nausea and vomiting, SUPPRESSION of adrenal steroid synthesis

PK: Rapid onset and Short Duration

Question 8

What is the MOA, Clinical use, advantages, adverse effects and PK of Propofol/Fos-Propofol?

Answer 8

MOA: ENHANCES INHIBITION by binding to GABAA receptor complex (i.e., agonist)

Clinical Use: MOST COMMONLY USED IV GENERAL
ANESTHETIC for INDUCTION and maintenance (propofol)

Advantage: Post-op nausea is RARE (Anti-emetic properties)

Adverse Effects: Pain on venous injection and supports bacterial growth (emulsion)

PK: Rapid recovery;
Fos-propofol - - PRO-DRUG