C&P: Local Anaesthetics Flashcards
Ester (-COO-) Local Anaesthetics
Procaine, Amethocaine
Amide (-NHCO-) Local Anaesthetics
Lidocaine, Prilocaine, Bupivacaine, Ropivacaine, Mepivacaine
pH of Local Anaesthetics
All are weak bases, they have hydrophilic plus hydrophobic components liked by an ester or amide group (hence classification)
Local Anaesthetics acting as Vasodilators
prilocaine >lidocaine >bupivacaine >ropivacaine
Potency
Related to lipid solubility
Speed of onset
Related to pKa
Duration of action
Related to protein binding
Metabolism of ester local anaesthetics
esterases break down to para-aminobenzoic acid (allergenic)
Metabolism of amide local anaesthetics
by hepatic amidases
Procaine: Relative Potency
1 (ie itself)
Procaine: Onset/Duration
slow onset, short duration
Procaine: Maximum dose (mg/kg)
12
Procaine: Toxic plasma level (mg/ml)
not in C&P
Procaine: pKa
8.9
Procaine: Protein bound (%)
6
Procaine: Relative lipid solubility
1 (ie itself)
Lidocaine: Relative Potency
2
Lidocaine: Onset/Duration
fast onset, medium duration