A: 1-5 Flashcards
How can we block the sensory transmissionfrom from a local area of the body to the CNS?
Inhibition of voltage dependent Na+ ch.
What will enhance the effect of local anesthetics?
Elevated extracellular K+ conc.
What will antag. the effect of local anes.?
Elevated E.c Ca2+ conc.
Give the properties of the best molecule to cross the lipid membrane?
Lipid soluble
Non-ionized
Uncharged
Which molecule is more effective in blocking?
Non ionizing/Ionizing
Ionizing
Nerve fiber sensitivity- What are the properties of a nerve that will get block fast?
Small fiber diameter
Myelinated
High firing rate
Anatomic location
Which fiber type is considered to be heavily myelinated?
Type A
Except _____ all local anesthetics are _____
Cocaine
Vasodilators
Local anesthetics can be devided into two groups
Amides
Esters
Local anesthestics- Amides can be devided into 2
Long acting: Bupivacaine, ropivacaine
Medium acting: Lidocaine, articain
Local anesthetics- Esters
Surface acting: Cocaine, benzocaine
short action: procaine
long action: tetracaine
Which are the short acting Amides?
Lidocaine
Articaine
Lidocaine MOA
Blockage of VDNaC
Which local anesthestic has the fastest duration of action?
Articaine
אתה מלקק ארטיק וזה ישר עושה לך בריין פריז
Lidocaine metabolism
CYP 450
Lidocaine duration of action
1-2 h
What can prolonged the duration of action of Lidocaine?
Epinephrine co-admin.
Which is the Amides long acting agent?
Bupivacaine
Bupivacaine duration of action
3-6 h
Bupivacaine metabolism
CYP 450
Cocaine metabolism
Plasma Cholinesterase
Cocaine duration of action
1-2 h
When is Cocaine used?
Procedures requiring high surface activity and vasoconstriction
Cocaine side effects
CNS
Arrhythmias
HTN
Coronary vasospasm
Drugs pKa
The pH at which the molecule is 50% ionized and 50% non ionized
The lower the pKa the more ____ the drug
Acidic
Lipid solubility of a drug is invrsley proportional to
Its charge
Urine alkalization will promote excrtion of which drugs?
Isonizaid
Weak acids
Urine acidification will promote excrtion of which drugs?
Morphine
Nicotine
Weak base
Volume of distribution=
Amount of drug in the body / Plasma drug conc.
Example for a drug which is highly bound to plasma proteins
Warfarin is bound to Albumin
NASID’s can displace Warfarin from Albumin
Pharmacokinetics include
Absorption
Distribution
Metabolism
Elimination
Phase I reaction possabilities
Oxidation
Reduction
Hydrolysis
Types of elimination
First order
Zero order
First order elimination
Rate of elimination is proportional to plasma conc.
Constant fraction of drug is eliminated per unit time
Higher thee conc. –> Greater the amount eliminated
Zero order elimination
Rate of elimination is constant regardless of the conc.
Receptor theory=
Classic receptor theory
Two state receptor theory (inactive, active)
Spare receptor theory
Potency=
Amount of a drug required to produce a givven effect
Efficiacy=
Maximal effect an agonist can produce if the dose is taken into the highest tolerated level
The higher the ____________ the safer the drug
Theraputic index
Example for synergistic drug interactions
Additive
Aspirin and Ibuprofen
Example for synergistic drug interactions
Potentiation
Caffeine and NASID’s
Pharmacokinetics is=
How a body processes a drug
Process of drug developement
In vitro
Animal atudying
Clinical testing
Marketing
Clinical testing phases
Phase 1: 20-100 subjects. is it safe?
Phase 2: 100-200 does it work?
Phase 3: 1000-6000 double blind
