Local Anesthetics Flashcards
To increase the effects of local anaesthetics which drugs are administered? 
Vasoconstrictors usually alpha agonist sympathomimetic
Which Anaesthetic drug causes vasoconstriction on its own
Cocaine because it inhibits norepinephrine reuptake
dysfunction of what causes an increase in elimination half-life of amide local anaesthetic?
Liver dysfunction
What is the mechanism of action of local anaesthetics
Block voltage dependent sodium channels and preventing depolarization of the membrane
What ion concentrations enhance local anaesthetic activity
Increased extracellular K+
Decreased extracellular Ca+2

What kind of pH increases penetrability Of local anaesthetics 
Alkaline pH
What are the factors that increase the action of local anaesthetics (5)
- Alkaline pH
- myelinated fibres
- diameter of nerve fibre (smaller is blocked quicker)
- sensory fibre
- Location (fibres in the periphery blocked quicker)
Which drug has the fastest onset of action
Articaine
What are the drug toxicity of cocaine drug abuse
Cardiovascular toxicity including severe hypertension, cerebral hemorrhage, cardiac arrhythmias, and myocardial infarction
Name the metabolite that prilocaine Is metabolize to that’s capable of converting haemoglobin to Methemohlobin
O- toluidine
Which Type of local anaesthetic Is able to cause antibody formation
Ester type local anaesthetics
What are the toxicity of local anaesthetics / ADVERSE EFFECTS
- CNS effects such as sedation, restlessness, nystagmus, tonic clonic conversions.
- Cardiovascular effects such as Hypotension and arrhythmias
- Local Neurotoxic action
- Allergic reactions
- Mucosal irritation
- Methemaiglobanaemia
- Others 
Name local anaesthetic drugs in the sub class amides 
- Articaine
- bupivacaine
- levobupivacaine
- lidocaine
- mepivacaine
- Prilocaine
- ropivacaine
Name Local anaesthetic drugs That belong in the sub class esters
- Benzocaine
- cocaine
- procaine
- tetracaine
What are the factors AFEECTING local anaesthetic action (5)
- PKa
- Degree of plasma protein binding
- rate of diffusion
- lipid Solubility
- presence of vasoconstrictor
What is the relationship between lipid Solubility and onset of action
Direct. The higher the solubility the more potency of the drug
What is the significance of the presence of vasoconstrictor
- Prolongs the duration of action of local anaesthetic
- Decreases bleeding
- Slow absorption and therefore reduces systemic toxicity
What are the disadvantages of using vasoconstrictor with local anaesthetic
- Vasospasm and ischaemia
- Adrenaline can cause systemic toxicity
- Delay in wound healing
Which drug is more cardio toxic
Bupivacaine
Esther linked local anaesthetics are metabolized by which enzyme
Plasma cholinesterase
Which organ metabolizes amide linked drugs
Liver
Which drugs are capable of causing methaemoglobinaemia
Articaine and prilocaine
Which drug at low concentrations Can be used for epidural analgesia during labour
Bupivacaine
Which drug is used to Anesthetize gastric mucosa and relief in gastritis
Oxethazaine
Which drugs are used for spinal anaesthesia
Lignocaine
tetracaine
bupivacaine 
What is the drug interaction between lignocaine and propranolol
Propranolol reduces hepatic blood flow and impairs clearance of lignocaine leading to toxicity
Explain the drug interaction between procaine and sulphonamides
Procaine is hydrolyzed into PABA And this reduces the effect of sulphonamides
