IV induction agents

 

Propofol vs thiopentone

• History
• Pharmaceutics
• Pharmacodynamics
• Pharmacokinetics
  * Organ system effects (CVS, resp, etc)

Others

• Non-anaesthetic uses
• Adverse effect profile
• Intra-arterial injection
• MH trigger
• PONV
• Prophyria
• Contraindications

 

Mode of actions - May be agent specific

 

Ligand gated

GABAa receptor

Glycine receptor

Serotonin 5HT receptors

Nicotinic acetylcholine receptors

Iontotropic receptors

 

 

GABA receptor

Inhibitory

Chloride channel --> Hyperpolarise cell

2 alpha, 2 beta, 1gmma

Great heterogenecity

Most anaesthetic agents act on GABAa except xenon, cyclopropane, N2O, ketamine

 

Barbiturates

Widespread effect

GABAa

No action on NMDA

 

Propofol, etomidate -- specific for GABAa

 

Ketamine acts on NMDA

 

 

Thiopentone vs propofol in general

 

Thiopentone vs propofol in TIVA

 

 

 

Remifentanil

Short HL depends on metabolism through easterase AND small initial Vd