Pharm of General Anesthetics Flashcards
3 examples of regional anesthesia
Epidural
Spinal
Peripheral nerve block
How do local anesthetics work
Ex: lidocaine, prilocaine, bupivacaine
Na channel blocker and prevents the propagation of nerve action
Pharm of general anesthesia (2 modes)
Increase inhibitory NTs (GABA, glycine)
Decrease excitatory NTs (nACh, NMDA, glutamate)
Alpha vs beta phase
A: redistribution from central compartments to peripheral tissue (start with the vessel rich group, then blood, muscle, fat)
B: drug metabolism (plasma and liver enzymes) and excretion
Context sensitive half-time
The time taken for blood plasma concentration of a drug to decline by one talk after an infusion has stopped
The shorter = the faster they wake up
Propofol
MOA, biotransformation, side effects
Facilitation of inhibitory neutrotransmission mediated by GABA
Conjugation in the liver results in inactive metabolites that are eliminated by renal clearance
Hypotension, bradycardia
Ketamine
MOA, biotransformation, side effects
NMDA antagonist (increased catecholamines and serotonin)
Inhibits excitatory NT effects in brain
Acts as a dissociative anesthetic by dissociating the thalamus from the limbic cortex
Transformation in the liver (some metabolites retain anesthetic activity)
SE: tachycardia, hypertension, dissociative effects
Benzodiazepines
MOA, biotransformation, side effects
Receptor binding enhances the inhibitory effects of various NTs (GABA)
Transformation relies on the liver
SE: long context sensitive halftime
Remifentanil
Ultra short acting opiod with termination half life < 10 mins
3 mins regardless of duration of infusion
Intravenous vs inhalational induction
IV: common, rapid induction time, but potential loss of airway control
Inhalational: peds, maintains spontaneous ventilation until airway is controlled, but slow induction time, risk of apnea or obstructed airway
