Transcript local anesthetic agents

Review
Chapter 7
Are antibiotics useful in treatment caries?
NO
BECAUSE…DECAY NEEDS TO BE TREATED WITH A FILLING
NOT ANTIBIOTICS
PRODUCED BY: STREPTOCOCCUS MUTANS
For a localized dental infection, when is
drainage applied?
FIRST
IF DRAINAGE CANNOT BE DONE OR IF THE CLIENT IS
IMMUNOCOMPROMISED…ANTIBIOTICS ARE GIVEN
WHAT IS Pseudomembranous colitis?
INFLAMMATION OF THE COLON
WHEN GIVEN CLINDAMYCIN
PSEUDOMEMBRANOUS COLITIS, A CAUSE OF ANTIBIOTIC ASSOCIATED DIARRHEA (AAD), IS AN INFLAMMATION OF
THE COLON
Remember…
DEFINITIONS
The ability to kill bacteria; effect
is irreversible
The ability to inhibit or retard
the multiplication or growth of bacteria;
reversible
Concentration of the
antiinfective agent present in the blood or
serum.
• The importance of the serum level is that certain levels
of an antibiotic are required to produce an effect on
various types of organisms. For an antibiotic to be
effective, the dose given must produce this
DEFINITIONS
– Infection caused by proliferation of microorganisms different from those
causing the original infection
• Superinfection is more often caused by broadspectrum antibiotics and increases when taken for
a longer time period.
– In this case, a reduction in the number of gram positive and gram-negative
bacteria allows the overgrowth of the fungus Candida albicans.
• The pathogenic organisms emerging in a
superinfection generally are more difficult to
eradicate than the original organism and more
likely to exhibit resistance.
– most are caused by Staph or Strep
– The practitioner can cause and eliminate infections
DEFINITIONS
The difference
among the terms
antibiotic,
antiinfective, and
antibacterial is
that antibiotics
are produced by
microorganisms,
whereas the
other agents
may be
developed in a
chemistry
laboratory (not
from a living
organism).
– substances that act against or destroy
infections
– substance that inhibits or kills
organisms that can produce infection,
such as bacteria, protozoa, viruses etc.
– Substances that destroy or suppress
the growth or multiplication of bacteria
― Chemical substances produced by
microorganisms that have the capacity,
in dilute solutions, to destroy or
suppress the growth or multiplication of
organisms or prevent their action
WHAT DOES CULTURING MEAN?
MEANS GROWING THE BACTERIA
CULTURE AND SENSITIVITY IS THE ONLY WAY TO BE SURE A
DRUG WILL KILL OR INHIBIT THE GROWTH OF THE
INFECTING MICROORGANISMS.
Sensitivity involves exposing the organism to test antibiotics and determining
whether the organism is sensitive or resistant
An antibiotic disk with a zone around it
shows sensitivity. After the organism is
identified, it is grown on culture medium.
Observing whether the organisms are
sensitive or resistant to certain test
antibiotics assists in determining which
antibiotic to use in difficult infections.
One to two days are required before the results of the test
are available. Although antibiotic therapy can start before
this time, it may be changed after the results are available.
THEREFORE, Antibiotic therapy CAN be initiated
BEFORE the results of the test are available. If clinical
response has been adequate, the original antibiotic is often
continued despite sensitivity results.
MEANS GROWING THE BACTERIA
CULTURE AND SENSITIVITY IS THE ONLY WAY TO BE SURE A
DRUG WILL KILL OR INHIBIT THE GROWTH OF THE
INFECTING MICROORGANISMS.
Sensitivity involves exposing the organism to test antibiotics and determining
whether the organism is sensitive or resistant
WHAT IS SUPERINFECTION?
AN OVERGROWTH OF ORGANISMS
PRODUCED
WHAT ANTIBIOTIC HAS THE HIGHEST
INCIDENCE OF GI COMPLIANTS?
ERYTHROMYCIN
GENERAL ADVERSE REACTIONS & DISADVANTAGES ASSOCIATED WITH
ANTIINFECTIVE AGENTS
– Antimicrobial agents that can be used during pregnancy to
treat infections are limited
• Penicillin and erythromycin have NOT been associated
with teratogenicity and are often used
– Before any antibiotics are used in the pregnant dental
patient, the patient’s obstetrician should be contacted
• Metronidazole is not usually used & Tetracyclines are
contraindicated
– Tetracycline: because of their effect on developing teeth and
skeleton
MUST KNOW..
• Divided into 4 groups:
1. Penicillin G and V **
2. Penicillinase-resistant penicillins
3. Ampicillins – includes amoxicillin
**
4. Extended-spectrum penicillins
** most commonly used in dentistry
Within the
group ONLY
Penicillin G
is
considered
to be the
natural
penicillin
*See note
• See Table 7-3; Page 83 for FYI review
MUST KNOW..
WHAT IS THE MOST COMMON
ANTIBIOTIC FOR DRUG ALLERGIES?
PENICILLIN
PENICILLINS
THE SALTS OF PENCILLIN G
• The potassium salt given intravenously
produces the most rapid and highest blood
level.
•
The penicillin’s duration of action is inversely proportional to the solubility of the
penicillin form: the least soluble is the longest acting.
• The benzathine salt given intramuscularly
produces the lowest and most sustained
blood level.
PENICILLIN
WHAT IS THE USUAL DOSE OF PEN V?
500 mg 4 times a day
PENICILLINS
• The usual adult dose of Pen V for treatment of
an infection is:
– 500 mg qid (4x a day) for the treatment of
an infection
– for a minimum of 5 days and preferably for
7 to 10 days.
500 mg 4 times a day
WHAT IS CLEOCIN?
CLINDAMYCIN
RATIONAL USE OF
ANTIINFECTIVE AGENTS IN
DENTISTRY
• Stage 1
• Stage 2
• Stage 3
RATIONAL USE OF
ANTIINFECTIVE
AGENTS IN
DENTISTRY
• Acute abscess and cellulitis are primarily the
result of gram-positive organisms
– THE DRUG OF CHOICE IS: penicillin V for patients
who are not allergic to penicillin
• 500 mg every 6 hours for 5 to 7 days
– Erythromycin ethylsuccinate or clindamycin for
patients who are allergic to penicillin
RATIONAL USE OF
ANTIINFECTIVE
AGENTS IN
DENTISTRY
• Infection is mixed; can be
handled by attacking either the
gram (+) organisms or the (-)
anaerobes
Clindamycin or
metronidazole
would be the
best choice to
attack the
anaerobes in a
stage 2
infection
– Gram-positive organisms can be managed with the
same drugs as in stage 1(Erythromycin or
clindamycin for patients who are allergic to
penicillin)
– For anaerobes, an antiinfective with good anaerobic
coverage is needed
• The two antibiotics with the most anaerobic
coverage are clindamycin and
metronidazole
• Penicillin V also has anaerobic coverage
RATIONAL USE OF
ANTIINFECTIVE
AGENTS IN
DENTISTRY
• The organisms have coalesced into one area
and are almost solely anaerobic
– Most often, incision and drainage is sufficient
– If chronic infection persists or the patient is
immune compromised, use of antibiotic with
anaerobic coverage is warranted
• Oral-cavity infections are generally understood
to advance through three stages.
– The three stages are:
• (1) mixed aerobic and anaerobic infection,
• (2) aerobic infection,
• (3) anaerobic infection.
– YET, what order do these stages occur?
• THEREFORE, the order of the stages for
oral infections occur as follows:
• (2) aerobic infection,
• (1) mixed aerobic and anaerobic infection,
• (3) anaerobic infection.
Chapter 8
WHAT ARE ANTIBIOTICS AND
ANTIINFECTIVES NOT AFFECTIVE
AGAINST?
Fungal or Viral Infections
IS FUNGUS ACUTE, CHRONIC, OR
BOTH?
CAN BE BOTH
• ANTIFUNGAL AGENTS: Substances
that destroy or suppress the growth or
multiplication of fungi
• Infrequent but when present, difficult to
treat
• Insidious (sneaky and quick)
• More likely to occur on
immunocompromised patients
• Can become chronic (long-standing)
• Can be divided into 2 divisions:
FUNGAL INFECTIONS
Mucocutaneous
Systemic
•skin or mucosa
•whole body
•commonly seen in •more serious in
the dental setting
nature
•treated with topical
or systemic
antifungal agents
•also, commonly
occur in the vaginal
canal
HOW COULD AN ORAL
CANDIDIASIS INFECTION BE
TREATED IN THE MOUTH?
AN ANTIFUNGAL..
ORAL CANDIDAL INFECTIONS ARE OFTEN TREATABLE WITH
ORAL ANTIFUNGAL LOZENGES AND RINSES
CANDIDA ALBICAN
• is part of the normal flora; overgrows if patient is on
long term antibiotics or ill fitting denture
(Mycostatin, Nilstat)
• is used for both the treatment and the
prevention of oral candidiasis in
susceptible cases.
• poor oral absorption:
• is not absorbed from the mucous
membranes or through intact skin;
taken orally, it is poorly absorbed
from the GI tract.
HOW COULD AN ORAL
CANDIDIASIS INFECTION BE
TREATED IN THE MOUTH?
HOW LONG SHOULD A NYSTATIN
RINSE REMAIN IN THE MOUTH?
2 minutes – for the BEST effect
WHAT IS NICKNAMED
‘AMPHOTERRIBLE’?
AMPHOTERICIN B
• Amphotericin B  poorest safety profile
• Also known as Fungizone
WHY ARE VIRUSES DIFFICULT TO
TREAT?
THEY CO-OPERATE WITH THE HOST
CELLS
MEANING…THEY WILL NOT DESTROY THE HOST OF A CELL
Remember also…
•
•
•
•
SUMMARY – KEY POINTS
Works by inhibiting replication of DNA
Food does not affect the drug’s absorption
The antiviral action of acyclovir includes
herpes simplex viruses types 1 and 2 (HSV-1
and HSV-2), Epstein-Barr and varicellazoster
One of the most common adverse effects
associated with oral acyclovir is headache.
•
Anorexia and a funny taste in the mouth have been reported rarely (not
common).
Remember also…
BY TAKING ABREVA – HOW MUCH IS
HEALING TIME REDUCED?
ONE HALF DAY
(NOT MUCH )
WHAT IS THE CATEGORY OF DRUGS
CALLED WHEN TREATING HIV?
ANTI-RETROVIRAL DRUGS
Examples of Drugs Used to Treat HIV
SEE NOTE
• Nucleoside reverse
transcriptase inhibitor (NRTI)
 zidovudine (AZT) (Retrovir)
• Nonnucleoside reverse
transcriptase inhibitor (NNRTI)
 nevirapine (Viramune) –
specific for HIV 1
• Protease Inhibitors
 saquinavir (Invirase)
CHAPTER 9
WHY IS EPI USED IN LOCAL
ANESTHETICS?
PROLONG DURATION
MEANING..THE LOCAL ANESTHETIC LASTS LONGER TO
ENSURE PROPER FREEZING OF THE TOOTH AND TISSUES
WHAT ARE SOME EXAMPLES OF
LOCAL ANESTHETICS USED TODAY?
• The amide lidocaine (Xylocaine) was released
in 1952
• mepivacaine (Carbocaine) was released in
1960
• More recently, bupivacaine (Marcaine) has
been made available for dental use
 potent local anaesthesia
 reversible local anaesthesia
 should be followed by complete recovery without
evidence of structural or functional nerve damage
 absence of adverse systemic effects &
allergic reactions
 rapid onset & good duration
 should have moderate lipid solubility which allows an
anesthetic agent to diffuse across lipid membranes of
all peripheral nerves (motor, sensory, autonomic)
 adequate tissue penetration
 low cost
 long shelf life (stability in solution)
 ease of metabolism & excretion
WHAT ARE THE TWO GROUPS OF
LOCAL ANESTHETICS?
AMIDES AND ESTERS
CROSS-HYPERSENSITIVITY BETWEEN AMIDES AND ESTERS
IS UNLIKELY
Absorption & L.A.
local
anaesthetic
(L.A.)
L.A.
tooth
• ↓ pH
• ↑ ionization
• ↑ [H+]
infection
L.A.
L.A.
EG: Lidocaine’s
pKa =7.9(Weak
base drug)
*Weak bases are
better absorbed when
the pH is greater than
the pKa
In the presence of infection, there may be a reduced clinical
effect of L.A. due to the ↓’d pH level. The infection site is
more acidic and more ionized and less likely to absorb the
L.A drug (weak base).
IF INFECTION IS PRESENT, HOW DOES
THE LOCAL ANESTHETIC REACT?
IT IS HARDER TO FREEZE –LIKELY
INFECTION MUST BE CLEARED BEFORE
FREEZING IS DONE.
IN THE PRESENCE OF AN ACIDIC ENVIRONMENT, SUCH AS
INFECTION OR INFLAMMATION, THE AMOUNT OF FREE BASE
IS REDUCED
WHAT DOES ADME STAND FOR?
VERY IMPORTANT!
ABSORPTION
DISTRIBUTION
METABOLISM
EXCRETION
• Addition of vasoconstrictor to local anesthetic:
Reduces the blood supply to the area
so as to ↓ rate of diffusion of anaesthetic
into the blood vessels
this also prolongs the duration &
effectiveness of the desired action
decreases bleeding in the area
Limits systemic absorption
Reduces systemic toxicity
LA agents are metabolized differently, depending
on whether they are amides or esters.
• AMIDES: are metabolized primarily by the liver
• In severe liver disease or with alcoholism, amides may
accumulate and produce systemic toxicity
• ESTERS: are hydrolyzed by plasma
pseudocholinesterases and liver esterases
• Although toxicity to local anesthetics is
rare in the doses normally used in
dentistry, patients can still suffer from a
classic toxic reaction.
LOCAL ANESTHETIC TOXICITY
causes stimulation of the CNS
including:
restlessness,
tremors
seizures
followed by CNS depression and
coma.
HOW MANY CARPS ARE MAX FOR
LIDOCAINE?
8.5 CARPS
WHY WOULD A HEMATOMA BE
PRODUCED?
POOR INJECTION TECHNIQUE OR
EXCESSIVE VOLUME
• An autosomal dominant trait characterized by often
fatal hyperthermia with rigidity of muscles occurring
in affected people exposed to certain anaesthetic
agents
– particularly halothane & succinylcholine (G.A.’s)
• NOT related to amides!
– In the past, the belief was that the amide local
anesthetics might precipitate malignant hyperthermia, but
they are currently no longer implicated. Patients with a
family history of malignant hyperthermia can be given
amide local anesthetic agents.
POOR INJECTION TECHNIQUE OR
EXCESSIVE VOLUME
IF A WOMAN IS PREGNANT AND
ANESTHETIC MUST BE GIVEN…
..WHAT IS BEST?
LIDOCAINE
WHAT TYPE HAS A GREAT POTENTIAL
FOR ALLERGY?
AMIDES OR ESTERS?
ESTERS
I.
Amides (Only class of anaesthetics used
parenterally)
i.
ii.
iii.
iv.
I.
Lidocaine (Xylocaine)
Mepivacaine (Carbocaine)
prilocaine (Citanest; Citanest Forte)
bupivacaine (bu·piv·a·caine)
Esters (No esters are currently available in a dental
cartridge)
i.
ii.
iii.
procaine
propoxycaine
Tetracaine
**Esters are not used
in dentistry as local
anesthetics, but used
topically.
eg. Benzocaine.
SEE
NOTE
LA AGENT
NOTES
• procaine
• no longer used
• lidocaine (Xylocaine)
• most common used
• least painful
• can only use 100,000epi
• mepivacaine (Carbocaine;
Isocaine)
• shortest duration
• when no epi is needed.
• bupivicaine (Marcaine)
• Painful
• longest duration 6-8 hours
• articaine (Septocaine)
• the most potent
• prilocaine plain (Citanest)
• similar to lidocaine
• Prilocaine epi (Citanest Forte) • rapidly metabolized
WHAT IS THE MOST COMMON LA
USED IN DENTISTRY?
LIDOCAINE 2% - (1:100 000 EPI)
WHICH ONE HAS THE LONGEST
DURATION OF ACTION?
MARCAINE
buprivacaine
(Marcaine)
• Has the longest duration of action.
– major advantage  greatly prolonged duration of
action.
– indicated in lengthy dental procedures when pulpal
anesthesia of greater than 1.5 hours is needed or
when postoperative pain is expected.
• Related to lidocaine & mepivacaine
• More potent but less toxic than the other amides
• Available in dental cartridges as a 0.5% solution
with 1:200,000 epinephrine
WHAT IS BOTH AN ESTER AND AN
AMIDE?
ARTICAINE
IF A CLIENT HAS UNCONTROLLED BLOOD
PRESSURE – CAN LA BE GIVEN IN A
CONTROLLED DOSE?
NO – IT IS BEST TO DELAY
TREATMENT
A CARDIAC PATIENT
can be given
2.0 CARTRIDGES
of
1:100,000 epinephrine
without
exceeding the
cardiac dose.
WHAT IS THE MAXIMAL SAFE DOSE
FOR A HEALTHY CLIENT?
0.2 MG OF EPI
THE MAXIMAL SAFE DOSE OF EPINEPHRINE FOR THE
HEALTHY PATIENT IS 0.2 MG AND FOR THE CARDIAC
PATIENT IS 0.04 MG
WHAT IS ORAQIX?
SOMETHING THE RDH CAN USE TO
FREEZE THE GUMS
CHAPTER 10
CAN NITROUS OXIDE BE USED ALONE
AS AN ANESTHETIC?
NO!
WHAT ARE THE STAGES/PLANES OF
ANESTHESIA?
STAGES…
STAGE I – ANALGESIA
STAGE II – DELIRIUM OR EXCITEMENT
STAGE III – SURGICAL ANAESTHESIA
STAGE IV – RESPIRATORY OR MEDULLARY PARALYSIS
VERY IMPORTANT…
Stage I – Induction Period
Nitrous oxide, as used in the
dental office, maintains the
patient in STAGE I
Analgesia
Analgesia
Amnesia
Euphoria
consciousness
Stage II – Induction Period
Excitement
Excitement
Delirium
combativeness
Stage III
Surgical
Where most major surgery is Anesthesia
performed
Divided into four planes
Unconsciousness
Regular respiration
Decrease in eye movement
loss of respiratory control
Stage IV
Respiratory arrest
Cardiac depression and arrest
No eye movement
Medullary
Depression
VERY IMPORTANT…
WHAT IS NITROUS OXIDE?
COLORLESS AND ODOURLESS GAS
ANTIANXIETY AGENT + ANALGESIC AGENT
WHY IS NITROUS OXIDE NOT GOOD TO
USE AS A GENERAL ANESTHETIC ALONE?
MAC > 100
BECAUSE OF ITS LOW POTENCY (MAC > 100), IT IS
UNSATISFACTORY AS A GENERAL ANESTHETIC WHEN USED
ALONE
IF, HOWEVER, ANESTHESIA IS FIRST INDUCED WITH A RAPIDLY
ACTING IV AGENT AND N2O/O2 IS ADMINISTERED IN
COMBINATION WITH A VOLATILE ANESTHETIC, EXCELLENT
BALANCED ANESTHESIA IS PRODUCED
THEREFORE,
Nitrous oxide combined with a halogenated
inhalational anesthetic (N2O/O2)
DECREASES THE MAC
• N2O/O2 is given throughout most surgical procedures that
necessitate the use of general anesthesia because it reduces
the concentration of other agents needed to obtain the desired
depth of anesthesia.
The average percentage of nitrous
oxide required for patient comfort is
35%.
•
DELIVERY:
 100% O2 (2-3 minutes) → N2O added in 510% increments → until patient response
indicates level of sedation reached→ after
termination of N2O, 100% O2 (at least 5
minutes)
WHY SHOULD THE CLIENT BE PLACED
ON 100% OXYGEN AFTERWARDS?
TO AVOID DIFFUSION HYPOXIA
WHAT COLOR IS THE NITROUS TANK?
BLUE
**REMEMBER THIS!
• Complications have been the result of misuse
or faulty installation of equipment
• NO2 tank → blue
• O2 tank → green
DON’T GET THESE
MIXED UP!!
• Cylinders are “pin coded” to prevent mixing
of cylinders and lines
• NO2 concentration should be automatically
limited and have a fail-safe system that
shuts off automatically if the O2 runs out
WHEN SHOULD NITROUS NOT BE
USED?
IF THEY HAVE TROUBLE BREATHING…
USE OF NITROUS OXIDE IS CONTRAINDICATED IN PATIENTS
WITH ANY TYPE OF
UPPER RESPIRATORY OR PULMONARY OBSTRUCTION
CHAPTER 11
KEEP IN MIND…
• Stress or anxiety due to dental treatment can
be treated with both pharmacologic and
nonpharmacologic methods.
• The treatment of choice is often dependent
upon the patient and his or her stress level.
• The normal sedative dose (calms normal
patient without dental appointment) is not
expected to produce calmness in the dental
patient,
• but the hypnotic dose (that which induces
sleep in the normal patient) can often
produce the desired degree of sedation
KEEP IN MIND…
WHAT IS THE MOST COMMON WAY TO
TREAT ANXIOUS PATIENTS?
ORAL SEDATIVES OR IV?
ORAL SEDATIVES
However,
the dose of a particular antianxiety
agent effective for a particular patient is
vastly variable and thus,
is NOT predictable.
WHAT DOES A LARGER DOSE OF ANTANXIETY AGENTS PRODUCE?
INDUCES SLEEP
(A SMALL DOSE PRODUCES SEDATION)
Antianxiety Agents
Sedatives**
Hypnotics
** can be sedative or hypnotic –
depending on dose; larger doses
provide hypnotic effect
WHAT ARE THE MOST COMMON
PRESCRIBED ANTI-ANXIETY DRUGS?
SEE
NOTE
EXAMPLES
alprazolam (Xanax)
chlordiazepoxide (Librium)
clonazepam (Klonopin)
chlorazepate (Tranxene)
diazepam (Valium) – very popular
estazolam (ProSom)
flurazepam (Dalmane)
halazepam (Paxipam)
lorazepam (Ativan) -newer form of benzodiazepines - popular
midazolam (Versed)
oxazepam (Serax)
quazepam (Doral)
temazepam (Restoril)
triazolam (Halcion)
WHAT IS THE PREFERRED AGENT
USED FOR THE ELDERY?
LORAZEPAM
WHAT IS PTOSIS?
DROOPING OF THE UPPER EYELID
IF DRUGS ‘NEED’ TO BE TAKEN DURING
PREGNANCY, WHEN IS THE BETTER TIME?
2ND TRIMESTER
D U R I N G T H E 1 ST T R I M E S T E R , M A L F O R M A T I O N S H A V E B E E N
REPORTED
Remember..
OVERVIEW
• Abuse & Addiction potential is less than that of
the barbiturates
• Physical dependence and tolerance can develop
• Combining with other CNS depressants can
reduce the safety and can become lethal
• Overdose poisoning is rare; difficult to achieve
when used alone
• The addition of alcohol can result in coma,
respiratory depression, hypotension, or
hypothermia
WHAT IS EMESIS?
INDUCED VOMITTING
USED WITH OVERDOSE – SUCH AS ACTIVATED CHARCOAL
AND SALINE
WHAT CAN BE USED TO REVERSE THE
EFFECTS OF BENZODIAZEPINES?
flumazenil
(ROMAZICON),
IN THE IV FORM
WHAT ARE SOME WAYS TO MANAGE
INSOMNIA?
Insomnia Management
The following habits should be followed to
minimize insomnia :
A. Light snack (warm milk) at bedtime
B. Awake at 6 AM even if sleep only began at 5
AM
C. Exercise during the day, but NOT within 3
hours of bedtime.
D. Remaining in bed no longer than 20 minutes
without sleeping
WHAT ARE SOME WAYS TO MANAGE
INSOMNIA?
This next slide will likely be on the exam
..…
• Absorption: barbiturates are well absorbed
orally and rectally; used intravenously but not
intramuscularly
• Distribution: IV agents are inactivated by
redistribution from site of action in the CNS, to
muscles, and adipose tissue
• Metabolism: short- and intermediate-acting
barbiturates are rapidly and almost completely
metabolized by the liver
• Excretion: long-acting barbiturates are largely
excreted through the kidneys as a free drug
WHAT ARE LONG ACTING
BARBITURATES USED FOR?
USED FOR EPILEPSY
phenobarbital (Luminal)
most commonly used for its
anticonvulsant effect because
of its long-acting effects
USED FOR EPILEPSY