pre-anestethetic medications

Question 1

What are Pre-anestethic medication used for?

Answer 1

Drugs used prior to anesthesia to make it safer and more pleasant for the patient

Question 2

What are the pre-anthesthetic drugs?

Answer 2

Relieve anxiety – Benzodiazepines
Provide analgesia – Opioids
Prevent allergic reactions – Antihistamines
Prevent nausea & vomiting – Anti-emetics
Prevent muscle contractions – SM Relaxants

Question 3

What are the benzodiazepines?

Answer 3

Midazolam*,
Lorazepam,
Triazolam

Question 4

What is the use and MOA of benzodiazepines?

Answer 4

USE: Reduce anxiety and facilitate sedation

MOA: Bind to GABAA receptor complex

Question 5

What is the most commonly used benzodiazepine?

Answer 5

MIDAZOLAM – MOST COMMONLY USED ---- 
   LESS ADVERSE EFFECTS: 
   NON-irritating, NO active 
   metabolites --- SHORT 
   DURATION of ACTION

Question 6

What are the opioids?

Answer 6

Fentanyl,
Sufentanil,
Alfentanil,
Remifentanil

Question 7

What is the use and PK of opioids?

Answer 7

USE: Sedation & Pre- and Post-op Analgesia; Sole anesthetic for minor surgeries; blunting of response to intubation

PK: Decrease MAC of inhalation anesthetics

Question 8

What is the MOA and adverse effects of opioids?

Answer 8

MOA: Bind to µ-opioid receptors

Adverse Effects: Respiratory depression (Increases PCO2, Cerebral blood flow, ICP)

Question 9

What is the use and MOA of antihistamines?

Answer 9

USE: Sedation, Dry bronchial secretions,
Anti-Emetic properties (H1), Gastric secretions/acidity (H2)
-
MOA: H1 (hydroxyzine, promethazine) &
H2 (cimetidine, famotidine , rantidine,
nizatidine) receptor blockers

Question 10

What is the use and MOA of antiemetics?

Answer 10

• USE: Pre- and post-op nausea & vomiting

MOA: D2 (droperidol, prochlorperazine) &
5-HT3 (ondansetron, granisetron,
dolasetron) receptor blockers

Question 11

What is the use of skeletal muscle relaxers?

Answer 11

USE: 1) Facilitate intubation

2) Provide optimal muscle relaxation before surgical procedures

Question 12

What is the MOA of skeletal muscle relaxants?

Answer 12

: Bind to nicotinic receptors at NMJ to
produce a DEPOLARIZING BLOCK
(succinylcholine) or competitive ANTAGONIST
of nicotinic receptors (atracurium, rocuronium,
vecuronium, mivacurium, pancuronium) – muscle
paralysis- REVERSED by ACHE inhibitors (e.g.,
neostigmine)

Question 13

What are the adverse effects of skeletal muscle relaxants?

Answer 13

malignant hyperthermia, hyperkalemia, bradycardia (succinylcholine), histamine release (atracurium), tachycardia (pancuronium)