Local Anesthetics - 8/22 Kruse Flashcards
What local anesthetics have a long duration of action?
BRT
Bupivacaine
Ropivacaine
Tetracaine
What drug has poor solubility in water and is used topically for derm conditions, hemorrhoids, premature cumming, and as an anesthetic lubricant?
Benzocaine
What has a longer, faster, more extensive action:
Lidocaine or procaine?
Lidocaine
What drug is metabolized to a P-aminobenzoic acid?
What does it inhibit?
Procaine
Sulfa antibiotics
Which drugs have the highest potency and duration of action?
Bupivacaine
Ropivacaine
Tetracaine
BRT
What drug is the alternative choice for people sensitive to ester local anesthetics?
Lidocaine
How can a local anesthetic cause both sensory and motor paralysis?
Nerve trunk contact
MOA of local anesthetics?
VGNa Channels
What hydrolyzes esters?
Amides?
Butyrycholinesterase
CYP450s
What type of drugs are generally shorter acting and are more prone to hydrolysis?
Esters
When large doses of local anesthetic are required, what premedication can be used as a prophylaxis?
What route of administration?
Benzodiazepine (diazepam or midazolam)
Parenterally
What drug is primarily used as a topical anesthetic of the upper respiratory tract?
Cocaine
High [ ]’s of local anesthetics can produce what side effects?
Nystagmus, muscular twitching, convulsions
What local anesthetics have a medium duration of action?
Lidocaine
Mepivacaine
Articaine
Cocaine
Low [ ]’s of local anesthetics can produce what side effects?
Sleepiness, light-headedness, visual and auditory disturbances, and restlessness
Where are esters metabolized?
Amides?
Plasma
Liver –> urine (charged substance)
What vasoconstrictor is useful when paired with short acting drugs?
Epinephrine
What drug is used as a class Ib antiarrhythmic agent?
Lidocaine
When is a Bier Block used?
What else is needed?
For short surgical procedures of the UE and LE less than 60 min
Proximally placed tourniquet
What are the most sensitive fibers to nerve block?
Type C in the dorsal root and sympathetic
Type B in the preganglionic-autonomic
What drug is now only used as a topical cream on the skin bc of toxicity with injections?
Dibucaine
What drug is used only for infiltration anesthesia?
Procaine
What drug is capable of producing prolonged anesthesia and has a tendency to provide more sensory block than motor?
Bupivacaine
What gets blocked 1st?
Small or large fibers? Myelinated or non-myelinated? Lipophilic or lipophobic? Low or high frequency? C or A delta fibers?
Small Myelinated Lipophilic High f A delta
How do local anesthetics work?
Bind reversible to Na channels in nerves and block ion movement through the pore, blocking APs
What local anesthetic has a short duration of action?
Procaine
