4. If the local anesthetic has two “i”s in its
name; it’s an amide
Lidocaine
Prilocaine
Bupivacaine
Articaine
Mepivacaine
5. Pharmacology of Local Anesthetics
Pharmacokinetics of Local Anesthetics
Factors:
1) Uptake
2) Distribution
3) Metabolism (Biotransformation)
4) Excretion
9. جذب
•سطحی یا تاپیکال راه
–مخاطی پوستی سطوح از سطحی جذب
In pharyngeal mucosa uptake is slow
In bladder mucosa uptake is even slower
–امال تاپیکال حسی پمادبی
Eutectic mixture of local anesthesia (EMLA) has
been developed to provide surface anesthesia for
intact skin
11. انتشار
•می منتشر بدن های سلول تمام به حسی بی دارو
شود
•دارد را انتشار میزان بیشترین اسکلتی بافت
•زیر موارد به بستگی خون در حسی بی داروی میزان
دارد
– Rate at which the drug is absorbed into the
cardiovascular system
– Rate of distribution from the vascular compartment to
the tissues
– Elimination of the drug through metabolic or
excretory pathways
12. Elimination Half-Life
•دفع میزان50موضعی حسی بی ماده ز ا درصد
One half life 50% reduction
Two half lives 75% reduction
Three half lives 87.5% reduction
Four half lives 94% reduction
Five half lives 97% reduction
Six half lives 98.5% reduction
13. All local anesthetics cross the blood brain barrier
All local anesthetics cross the placenta and enter the
blood stream of the developing fetus
19. Excretion of Local Anesthetics
kidneys are the major excretory organs for both local
anesthetics
esters appear in very small concentrations in the urine; this
is because they are almost completely hydrolyzed in plasma
Procaine (Novocaine) appears in the urine as 90% PABA
and 2% unchanged
10% of Cocaine is found unchanged in the urine
patients undergoing dialysis are likely to be unable to
excrete the unchanged portion of the esters or amides thus
increasing toxicity
20. موضعی حسی بی سیستمیک اثرات
CNS
CVS
Respiratory System
Local tissue toxicity
21. روی موضعی حسی بی اثراتCNS
the pharmacological action of local anesthetics on the
CNS is depression
at high levels, local anesthetics will produce tonic-
clonic convulsions
Procaine, Lidocaine, Mepivacaine, Prilocaine and
Cocaine generally produce anti-convulsant properties;
this occurs at a blood level considerably below that at
which the same drugs cause seizures
22. -Procaine, Lidocaine and Mepivacaine have
been used therapeutically to terminate or
decrease the duration of both grand mal and
petit mal seizures;
anti-convulsant levels(.5 to 4 micrograms/ml)
-The depressant action of local anesthetics raise
the seizure threshold by decreasing the
excitability of cortical neurons in epileptic
patients
23.
24. تشنجی فاز
Convulsive Phase
increased cerebral metabolism leads to acidosis
which prolongs the seizure activity even in the
presence of declining local anesthetic levels in the
blood
-seizures gradually subside generalized CNS
depression respiratory depression respiratory
arrest death
25. باش کننده تحریک تواند می دپرسانت داروی یک چگونهد
local anesthetics produce CNS excitation
through selective blockade of inhibitory
pathways in the cerebral cortex; inhibition of
inhibition is a pre-synaptic event that follows
local anesthetic blockade of impulses traveling
along inhibitory pathways; the local anesthetic
depresses the action of the inhibitory neurons
thus tipping the balance in favor of excessive
excitatory input tremor, agitation, seizure
and death
28. عروقی قلبی اثرات
local anesthetics have a direct action of the
myocardium and peripheral vasculature
CVS is more resistant to the effects local
anesthetics than the CNS
increased local anesthetic blood levels result in
decreased myocardial depolarization, however, no
change in resting membrane potential and no
prolongation of the stages of repolarization
31. تن دستگاه روی موضعی حسی بی اثراتفس
local anesthetics have a direct relaxant action
on bronchial smooth muscle
generally, respiratory function is unaffected by
local anesthetics until near overdose levels are
achieved
33. Malignant Hyperthermia
pharmacogenic disorder in which a genetic
variant alters the person’s response to certain
drugs. Tachycardia, tachypnea (rapid
breathing), unstable blood pressure, cyanosis,
fever muscle rigidity and death; 68% mortality
rate.
34. عروقی های کننده تنگ فارماکولوژی
• Vasoconstrictors
• Constrict blood vessels
• Constrict vessels and decrease blood flow to the site of injection.
• Higher LA concentration remains around the nerve increasing the
LA's duration of action.
• Absorption of LA into bloodstream is slowed, producing lower
levels in the blood.
• Lower blood levels lead to decreased risk of overdose (toxic)
reaction.
• Decrease blood flow
• Decrease the blood level of the drug
• Increase the concentration of drug at the site
• Decrease bleeding at site
35. • Minimize bleeding at the site of administration.
• Naturally Occurring Vasoconstrictors:
- Epinephrine
- Norepinephrine
• Vasoconstrictors should be included unless contraindicated.
• Mode of Action - Attach to and directly stimulate adrenergic
receptors . Act indirectly by provoking the release of
endogenous catecholamine from intraneuronal storage sites.
38. عروقی کننده تنگ انتخاب فاکتورهای
• Length of the dental procedure
• The need for hemostasis during and
following procedure
• The medical status of the patient