Anaesthetic Drugs

Question 1

Overall, describe the 2 main types of anaesthetic (and any subcategories) and when you would use them

Answer 1

General - used for surgery and sedation

• Volatile
• IV

Local/regional - used for many reasons including: dentistry, local procedures, post-operatively, obstetrics

Question 2

Explain overall how general anaesthetics work and give some examples of IV drugs

Answer 2

• Potentiate GABAa receptors (major inhibitory transmitter)
• Increased Cl entry
• Increases inhibition resulting in desired effects of anaesthetics
• Acts on various areas of the nervous system (reticular formation, thalamus, hippocampus, brainstem and spinal cord)
• Except Xenon, Nitrous Oxide and Ketamine which act via NMDA receptor

Examples of IV anaesthetics:

• Propofol
• Barbiturates
• Ketamine
• Etomidate

Question 3

Explain overall how local anaesthetics work and give some examples of local drugs

Answer 3

• Use-dependent block of voltage gated Na channels
• Preferentially binds to small, myelinated (afferent) nerves
• Therefore, results in block of nociceptive and sympathetic signals

Examples of local anaesthetics:

• Lidocaine
• Bupivacaine
• Ropivacaine
• Procaine