Pharmacology in implant dentistry
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Transcript of Pharmacology in implant dentistry
CONTEMPORARY IMPLANT DENTISTRY
CHAPTER 21
PRESENTER: MOSTAFA MONTAZERI
IntroductionIncrease in demand and use of dental implant Indications and protocol for the use of pharmacologic agents
There is no consensus on the pharmacologic protocol
Many practitioners use medications empiricallyin all procedures
2
AntimicrobialsAn important complication to prevent after implant surgery is Infection Antimicrobial therapy is an essential component of the surgical procedures
Adverse effects Mild and infrequent
Most common antimicrobials in implant dentistry:1. Antibiotics
2. Antimicrobial rinses (0.12% CHX gluconate)
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AntibioticsAntibiotic therapy in dentistry:
1. Prophylactic (Prevent infections)
2. Therapeutic (Treat infections)
4
Prophylactic AntibioticsIn oral implantology No consensus on the use and indications for prophylactic antibiotics
Adverse effects:
1. Development of resistant bacteria
2. Adverse reactions
3. Possible lax surgical technique
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Prophylactic AntibioticsEsposito and Hirsch One of the main causes of dental implant failure may be due to bacterial contamination at implant insertion
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Prophylactic AntibioticsSurgical wound infections
1. Presence of inoculum
2. Overcoming the host’s defenses
3. Allowing for the growth of bacteria
This process has many variables; Prophylaxis is only one component
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The efficacy and impact of antimicrobial prophylaxis has been proven to be significant
Prophylactic AntibioticsIn the most comprehensive and controlled study to date:
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Use of preoperative antibiotics significantlyimproved dental implant survival (4.6% vs. 10%
failure), both in early and later stages
Prophylactic AntibioticsMain goal of use Prevent infections during initial healing period A greater aseptic local environment is achieved
Study by Burke Scientific basis for the preoperative use of antibiotics
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Prophylactic AntibioticsPrinciples drafted from Burke’s study:
1. High-risk procedure
2. Selection of appropriate antibiotic
3. Appropriate tissue concentration of antibiotic
4. Use of the shortest effective antibiotic
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Prophylactic Antibiotics
Surgical wound classification with associated infection ratesClass 1: Clean (<2%)Elective non-traumatic surgery, no acute inflammation, respiratory, GI and biliary tracts no entered
Class 2: Clean-Contaminated (10-15%)Elective opening of the respiratory, GI and biliary tracts enteredElective dental implant and bone procedures (<1% by proper surgical technique and prophylactic antibiotics)
Class 3: Contaminated (20-30%)Inflammation, gross spillage from GI and biliary tracts
Class 4: Dirty/Infected (50%)Established clinical infection, perforation of respiratory, GI and biliary tracts
Principle 1:
The procedure shouldhave a significant riskfor and incidence ofpostoperative infection
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Class 2,3 and 4 procedures Use of prophylactic antibiotics
Prophylactic Antibiotics
Factors associated with increased risk of infection for dental implant proceduresSystemic factorsDiabetes, Long term corticosteroid use, Smoking, Immunocompromised systemic disorders, Malnutrition, Obesity, Elderly population, ASA 3 or 4
Local factorsUse/type of grafting material, Periodontal disease, Tissue inflammation, Odontogenic infection, Ill fitting provisional prosthesis, Incision line opening, Inadequate hygiene
Surgical factorsPoor aseptic technique, Skill/experience of the surgeon, Increased duration of surgery, Wound contamination during surgery, Foreign body (Implant)
Principle 1:
The procedure shouldhave a significant riskfor and incidence ofpostoperative infection
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One of the most significant surgical factors Poor aseptic technique:
Proper disinfection and draping, Hand scrubbing, sterile gowns
Prophylactic Antibiotics
Duration of the surgical procedure Second most critical risk factor affecting postoperative infection rates
◦ Less than 1 hour 1.3%
◦ More than 3 hours >4%
Rate of infection doubles with every hour of the procedure
Principle 1:
The procedure shouldhave a significant riskfor and incidence ofpostoperative infection
13
Prophylactic Antibiotics
Skill & Experience of the surgeon:
Less experienced surgeon (<50implants placed) 7.3%increase in failure rates
Principle 1:
The procedure shouldhave a significant riskfor and incidence ofpostoperative infection
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Prophylactic Antibiotics
Dental implant as a foreign body:
Presence of the implant can compromise the hosts’ defenses
Normal flora with low-virulence potential
Very difficult to treat
Principle 1:
The procedure shouldhave a significant riskfor and incidence ofpostoperative infection
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Prophylactic Antibiotics
Probability of wound infection by type of wound, risk index and ASA status
Principle 1:
The procedure shouldhave a significant riskfor and incidence ofpostoperative infection
16
Risk IndexOperationclassification 321
5.4%2.3%1.0%Clean
9.5%4.0%2.1%Clean-contaminated
Prophylactic Antibiotics
Most postoperative infections are caused by endogenous bacteria like:
Aerobic G+ cocci; Streptococci
Anaerobic G+ cocci; Peptococci
Anaerobic G- rods; Bacteroides
Oral infections; Mixed 𝑨𝒏𝒂𝒆𝒓𝒐𝒃𝒆𝒔
𝑨𝒆𝒓𝒐𝒃𝒆𝒔=
𝟐
𝟏
Anaerobes need aerobes to provide an environment to proliferate
The ideal antibiotic must be effective against these pathogens
Principle 2:
The appropriateantibiotic for thesurgical procedure mustbe selected
1- The antibiotic shouldbe effective against thebacteria that are mostlikely to cause aninfection
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Prophylactic Antibiotics
Adverse effects may vary from nausea to the extreme allergic reactions
Principle 2:
The appropriateantibiotic for thesurgical procedure mustbe selected
2- Use the antibioticwith least amount ofadverse effects
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Prophylactic Antibiotics
Advantages of bactericidal antibiotics:
1. Less reliance on host resistance
2. The bacteria may be destroyed by the antibiotic alone
3. Faster results
4. Better flexibility with dosage intervals
Principle 2:
The appropriateantibiotic for thesurgical procedure mustbe selected
3- The antibiotic shouldbe ideally bactericidal
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Prophylactic Antibiotics
Antibiotic should be given in a dose that will reach plasma levels that are ×3 to ×4 the MIC
To achieve this:
×2 therapeutic dose at least 1 hour before surgery
After bacterial contamination No preventive influence
Principle 3:
An appropriate tissueconcentration of theantibiotic must bepresent at the time ofsurgery
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Prophylactic Antibiotics
In a healthy patient:1. Continuing antibiotic after
surgery doesn’t decrease the rate of infections
2. A single dose of antibiotic is sufficient
In a high-risk patient:◦A longer dose of antibiotic
Principle 4:
Use of the shortesteffective antibiotic
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Complications of antibiotic prophylaxis6-7% incidence, life-threatening: minimal
Risks: GI complications, Colonization of resistant strains, Cross reactions, Allergic reactions
Allergic reactions: from mild urticarial (1-3%) to true anaphylaxis (0.01-0.04%)
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Complications of antibiotic prophylaxisPseudomembranous colitis: ◦ Unusual yet increasing complication
◦ Caused by C.difficile (Intestinal flora)
◦ Highest risk: Penicillins, Clindamycin
◦ Most common treatment: Vancomycin or Metronidazole
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Risks for Antibiotic-Induced Pseudomembranous Colitis
LowMediumHigh
TetracyclinsMetronidazole
Vancomycin
PenicillinErythromycinQuinolones
AmpicillinAmoxicillin
CephalosporinClindamycin
Diarrhea and Abdominal Cramping
Complications of antibiotic prophylaxisDevelopment of resistant bacteria:
Begins only after the elimination of host’s susceptible bacteria
Takes at least 3 days of antibiotic use
Short term use (1day) Little effect
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Antibiotics Used in Implant Dentistry1. Beta-Lactams: Penicillin V, Amoxicillin, Augmentin,
Cephalexin/Cefadroxil
2. Macrolides: Erythromycin, Clarithromycin, Azithromycin
3. Clindamycin
4. Tetracyclins
5. Fluoroquinolones: Ciprofloxacin
6. Metronidazole
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Beta-Lactams: Penicillin VoGood absorption
oSerum peak levels: 30 min
oDetectable in blood: 4 hours
oEffective against: Most Strep. species, Oral anaerobes
oMain disadvantage: Compliance (qHd), prone to resistant bacteria
26
Beta-Lactams: AmoxicillinoSuperior absorption, 70-80% bioavailability, Very low toxicity
oExcellent tissue diffusion in infected areas
oBroad-spectrum: G- cocci and bacilli, Streptococci and oral anaerobes (> Penicillin V)
27
Beta-Lactams: Amoxicillin/Clavulanic Acid (Augmentin)oAffinity for penicillinase-producingbacteria
oAs a suicide molecule; Inactivates the resistant bacteria
oIndication: In case with suspected penicillinase bacteria
oVery practical perioperative antibiotic for sinus augmentation
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Beta-Lactams: Cephalexin/CefadroxiloFirst generationoSimilar spectrum to amoxicillinoAdvantage: Not susceptible to beta-lactamase (S.aureus)oCross-reactivity with penicillin 8-18%oContraindicated only in type 1 hypersensitivity
oSecond and third generations Broader spectrum, Less cross-reactivity, greater resistance to beta-lactamase destruction
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MacrolidesoMost common used in dentistry ErythromycinoBacteriostatic Not ideal first choiceoAgainst Strep., Staph., some anaerobesoAlternative for penicillin-allergic patientsoExcellent absorption but affected by food consumptionoHigh incidence of nauseaoNumerous drug interactions Elevating serum levels of Digoxin, Theophylline, Carbamazepine, Terfenadine predug (Cardiotoxic Torsades de pointes, ventricular tachycardia)
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MacrolidesoThree novel macrolides Clarithromycin (Biaxin), Azithromycin (Zithromax)oThey do not inhibit cytochrome P450 isozymes
oBiaxin Less nausea and better G- activity
oZithromax Effective against H.influenza
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ClindamycinoActive against: Primarily anaerobes, aerobes such as Streptococci and Staphylococci, B.fragilis (superior)oAqueous solution 300mg/2ml Graft materials for sinus augmentation
oBacteriostatic in normal doses
oMain disadvantage: Diarrhea in 20-30% of patients treatedAlso can cause pseudomembranous colitis (PMC)
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ClindamycinoAnti-diarrheal medications should be avoided Hindering of fecal elimination of the pathogen
oIf continuing the drug is necessary Imidazole or Vancomycin, Metronidazole
oIf the condition persist >3 days Internist
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TetracyclinsoWide-spectrum activity: Strep., Staph., oral anaerobes, G-aerobic rodsoHigh degree of bacterial resistance (since 1950s)oPrimary agents for treating implant diseases and infectionsoQuestionable efficacy for managing infrabony defects (Inactivates when chelated with Ca complexes)
oDisadvantages: High incidence of Candidal infections, Photosensitivity reactions
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FluoroquinolonesoBactericidal and broad-spectrum, oral or parental
oCiprofloxacin was of the first generation of this group
oNewer generations Greater activity against resistant bacteria and anaerobes
oProphylactic and therapeutic treatment of sinus lifting procedure
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MetronidazoleoBactericidaloAnaerobic infections (rarely in mixed infections)o+Penicillin Severe infections
oDisulfiram-like reactions; Severe nausea and abdominal cramping
oCounteracts with Warfarin (Coumadin)
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Prophylactic Antibiotics in Oral Implantology1. Amoxicillin: Drug of choice
2. Cephalexin (non-anaphylactic allergy to penicillin)
3. Clindamycin (anaphylactic allergy to penicillin
For sinus involvement procedures:
1. Augmentin
2. Levaquin (History of taking antibiotics within past 4 weeks)
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Therapeutic Use of Antibiotics: Postoperative InfectionsAcute post-op infections: 3rd to 4th day after surgery
Local signs: Pain, inflammation, bleeding, exudate
Systemic signs: Fever, headache, nausea, muscle aches, vomiting, weakness
First-line medication: Broad-spectrum beta-lactam
Duration: 3 days beyond the clinical improvement (usually 7 days)
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Therapeutic Antibiotics in Implant Dentistry
The recommended treatment for intraoral infections:
1. Surgical drainage
2. Systemic antibiotics
3. 0.12% CHX gluconate; Τ1 2 oz BID for 2 weeks
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Therapeutic Antibiotics in Implant DentistryAmoxicillin 500mg; 2 immediately, TID 1 week
In case of allergy:
Clindamycin 300mg; 2 immediately, TID 1 week
No improvement after 4 days Culture and sensitivity test
Until then Levaquin 50mg/day, 1 week
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ChlorhexidineAnother modality for antimicrobial prophylaxis
Potent antibacterial
High substantivity at high concentrations, is bactericidal; by bacterial cytoplasm precipitation
Slow release from tissue surfaces; 12-hours
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ChlorhexidineIn vitro: Inhibitory effect of CHX on cultured epithelium and cell growth
Clinical studies have not shown this
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Chlorhexidine1. Reduce plaque accumulation
2. Enhance mucosal health
3. Improve soft tissue healing
4. Treat periodontal disease
5. Prevent alveolar osteitis
6. Tissue healing after extractions
7. Reverse peri-implantitis
8. No adverse effect on implant surfaces
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ChlorhexidinePreoperative CHX before implant surgery:
Significant reduction of infectious complications (2 to 1)
Six fold difference in implant failures
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Chlorhexidine1. Patient pre-surgical rinse
2. Surface antiseptic
3. Postsurgical rinse: twice a day until incision closure
4. Peri-implant maintaining on daily basis
5. Treatment of postoperative infections
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Management of postoperative inflammation
Cyclooxygenases and Prostaglandins Postoperative pain and inflammation
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Tissue damage
Arachidonic acid release
PGs
Edema
Steroids
NSAIDs Cyclooxygenase
NSAIDsAnalgesic and anti-inflammatory
Do not have a ceiling effect for inflammation
Higher doses to achieve anti-inflammatory effects Serious side effects
Ibuprofen is suggested in implant dentistry
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GlucocorticosteriodsAdrenal cortex Androgens and corticosteroids
Corticosteroids:
1. Glucocorticoids Carbohydrate metabolism, potent anti-inflammatory actions
2. Mineralocorticoids Sodium-retaining
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GlucocorticosteriodsSynthetic glucocorticoids Longer-acting and more potent than natural steroids
Anti-inflammatory effects:
Altering CT response to injury Hyperemia Exudation and cellular migration
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GlucocorticosteriodsDuration (hr)Equivalent dose (mg)PotencyGlucocorticoids
Short-acting
<12201.0Hydrocortisone
<12250.8Cortisone
Intermediate-acting
24-3654.0Prednisone
24-3654.0Prednisolone
Long-acting
>480.7525Dexamethasone
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Glucocorticosteriods: Mechanism of action
Binds to GRs within cells Glucocorticoid-GR complex Alteration of mRNA synthesis Different proteins
Also active lipocortins which inhibitphospholipase A2 (Key enzyme in releasing of arachidonic acid) PGs
51
Glucocorticosteriods: Adrenal suppressionAfter 7-10 days after steroid administration
In stressful situations Cardiovascular collapse
Amount of suppression
Short-term use Doesn’t significantly affect HPA axis and restore completely after 7 days
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1. Duration of treatment2. Dose administered
Glucocorticosteriods: TimingShould be based on the production of the natural steroid, Cortisol:
1. from plasma cholesterol 15-30mg/day
2. Stressful situations 300mg
3. Several-fold higher in the morning A dose of Dexamethasone in the morning doesn’t significantly alter the level of cortisol, but in the afternoon Complete suppression of HPA
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Glucocorticosteriods in medicine and dentistryHave been used in 2 ways since 1942:
1. Therapeutic treatment in various inflammatory and autoimmune diseases (Todays still used for this)
2. Prophylactic treatment of inflammation and pain
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Glucocorticosteriods in medicine and dentistry
In the dental literature, they have been shown to:
1. Advantageous in the prevention of post-operative complications after traumatic oral surgery, Intraoral sagittal osteotomy, vestibuloplasty with palatal mucosal grafts
2. Reduction of edema and pain after oral surgery
3. Less need of pain medication after surgery
4. Minimal effect on wound healing, infection and adrenal suppression
55
Glucocorticosteriods in implant dentistryIntegral part in the treatment of post-surgical edema after implant procedures
1. Drug of choice: Dexamethasone (Decadron)administered before surgery (in the morning)
2. The post-operative regimen should not exceed 3 daysafter surgery (for inflammation peaks between 48-72 hours)
3. The dose should not exceed the equivalence of 300mg of cortisol
56
Glucocorticosteriods in implant dentistryAdditional benefit of dexamethasone Antiemeticeffects for the prophylactic treatment of post-operative nausea and vomiting
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Glucocorticosteriods in implant dentistryContraindications:
1. Active infection
2. Tuberculosis
3. Ocular herpes simplex
4. Primary glaucoma
5. Acute psychosis
6. Diabetes mellitus anti-insulin action Glycosuria
58
CryotherapyApplication of cold dressing to reduce postoperative inflammation
In the form of ice bags minimize edema by:
1. Vasoconstriction of capillaries
2. Lower temperature Reduce cell metabolism
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Cryotherapy as an anti-inflammatory agentHighly advised in any implant procedure in which excessive inflammation is expected
20min on/ 20min off for the first 24-36 hours
No longer than 2 days
Prolonged use Rebound swelling and cell destruction
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Postsurgical Pain ManagementPain inadequately treated in 50% of all surgeries
Painful experiences Cause hyperalgesia and allodynia
Goal in oral implantology: adequate analgesic levels before cessation of LA and postoperative comfort
61
Preemptive analgesiaIntroduction of an analgesic regimen before theonset of noxious stimuli (Advantageous in implant surgery)
Factors affecting duration and intensity of postoperative pain: 1.Extent of reflection 2.Amount of bone preparation 3. Inherent factors 4. Duration of the surgery
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Mechanism of painNoxious stimuli Peripheral nociceptors Transmit signals to the dorsal root ganglion Synapse in the dorsal horn Spinothalamic tract Thalamus Cortex Interpretation of pain
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Mechanism of painRepeated Stimuli Nociceptors becomes more responsive
Sensitivity of nociceptors enhanced and magnified by tissue factors and inflammatory mediators such as:
PGs, kinins, Leukoterines, sP, Histamine
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Mechanism of painThe most important mediator PGs
Also synthesized in brain and spinal cord Enhance pain sensitivity
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Tissue damage
Arachidonic acid
COX-1 COX-2 COX-3 ??
Prostaglandins Prostaglandins
Platelet activity (Hemostasis)GI integrity
Regulation of kidney function
PainInflammation
Fever
NSAIDsAcetaminophen
COX-2 inhibitors
Mechanism of painOpioids Act on CNS by binding to µ-opioid receptors Prevention the release of substance P Prevent transmission on nociceptive pathways and activate inhibitory descending pathway
67
Analgesic classifications in dentistry
Non-opioids
NSAIDs
Acetaminophen
Tramadol
COX-2 inhibitors
Opioids
Codeine
Hydrocodone
Oxycodone
Meperidine
Adjuvants
Glucocorticoids
Long-acting anesthetics
Tricyclic antidepressants
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Management of postoperative pain
Non-opioids: AcetaminophenMode of action: Unknown; PG pathways within the CNS with little effect of peripheral PG synthesis
COX-3 enzyme Brain, spinal cord and heart Postulated to be the site of action of Acetaminophen
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Non-opioids: AcetaminophenIndication: Mild to moderate pain
Excellent analgesic and antipyretic properties
Ceiling dose for analgesic effect (4g/day)
Minimal anti-inflammatory qualities
Main side effect: Liver damage (long-term)
70
Non-opioids: NSAIDsEffective in all levels of pain
Work very well as analgesics and anti-inflammation
Analgesic doses Ceiling effect
Anti-inflammation doses No ceiling effect
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Non-opioids: NSAIDsSide effects:
1. GI disturbances (Dyspepsia, erosions, ulcerations)
2. Liver effects
3. Cardiac effects
Largest number of serious drug-related complications
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Relative risk of NSAIDs for GI complications
Relative riskNSAID
1None
2.1Ibuprofen
3.2Ketoprofen
4.3Naproxen
5.5Indomethacin
8 to 11Aspirin
24.7Ketrolac
Non-opioids: NSAIDsVery little effect on platelet aggregation; BTs are not prolonged
Prolonged use Interference with anti-hypertensive drugs (>5 days Monitor blood pressure)
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Non-opioids: IbuprofenMost popular prescribed NSAID
Mild to moderate pain
Analgesic ceiling dose 400mg/dose and 1200mg/day
74
Non-opioids: AspirinAt analgesic doses, its relative risk for GI complications is high
Aspirin is NOT a drug of choice in implant surgery; for its antiplatelet effects
75
Non-opioids: TramadolCentrally acting analgesic with 2 complementary characteristics:
1. opioid
2. anti-depressant
Mechanism: Inhibition of norepinephrine and serotonin reuptake
76
Non-opioids: TramadolFewer opioid-like side effects
Analgesic efficacy similar to codeine (60mg)
Indication: Moderate to moderately severe pain
Alternative in patients with NSAID-related GI complications and opioid intolerance
77
Non-opioids: TramadolUltracet(tramadol/acetaminophen) Excellent efficacy in pain studies; 3.75mg tramadol and 325mg acetaminophen
78
Non-opioids: COX-2 inhibitorsMain advantage: Lack of GI side effect
Several cardiovascular complications
Not better than Ibuprofen in terms of pain and inflammation management
79
Opioids (Narcotics)Primary medications for moderate to severe pain from dental origin
Centrally acting on µ and κ receptors
Morphine: Naturally occurring opioid
Do not have a ceiling effect; As the dose increases, analgesia increases
80
Opioids: CodeineNaturally occurring alkaloid
Mild analgesic
Excellent antitussive but with nausea and constipation
Orally: 60% bioavailable; 10% methylated to morphine (analgesic; 90% not analgesic)
Because of the side effects and low potency Not the first choice in oral implantology
81
Opioids: HydrocodoneSemi-synthetic narcotic analgesic and antitussive
Actions qualitatively similar to codeine
Usually used as a combination analgesic (+Ibuprofen or acetaminophen)
It is habit forming
Adverse reactions: Dizziness, sedation, nausea, vomiting
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Opioids: OxycodoneSemi-synthetic opioid
Analgesic action similar to morphine
Moderate to severe pain
Excellent oral bioavailability (retains 50% of its analgesic activity)
Combination (+acetaminophen or aspirin)
83
Opioids: MeperidineMostly in hospital settings (IM)
Very strong CNS stimulant
Poor oral bioavailability (25%) Poor choice for an orally administered opioid
84
Combination Analgesic Therapy for Postoperative PainGoal: Increase the analgesic effect while decreasing possible side effects
Acetaminophen or NSAIDs + An opioid
Because of the ceiling effect of the formers, no additional analgesia with dosage increase
85
Mild painSelf-limited
Normal recommended doses of NSAIDs
86
Moderate painWill not be resolved totally by NSAIDs
Interfere with function
Disrupt the activities of daily living
87
Severe painInterferes with some or all of the activities of daily living
Strong opioid treatment for days
Adjuvant drug therapies
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Control of Postoperative Surgical PainWHO: Analgesic “ladder”; three steps:
1. Maximize the use of NSAIDs for mild to moderate pain, Adjuvants such as glucocorticoids and cryotherapy suggested
2. Non-opioid + adjuvant + opioid (moderate)
3. Non-opioid + adjuvant + opioid (severe)
89
Recommend Pain Control Protocol (PCP)
DoseDrug
PCP1: Mild pain expected
400mg, 1 hr before surgeryIbuprofen
PCP2: Mild to moderate pain expected
400mg 1hr before surgery + continue QID for 2 days5mg/500mg as needed
Ibuprofen + Hydrocodone
PCP3: Moderate pain expected
400mg 1hr before surgery + continue QID for 2 days7.5mg/750mg QID for 2 days, then as needed
Ibuprofen+Hydrocodone
PCP4: Severe pain expected
400mg 1hr before surgery + continue QID for 4 days10mg/660mg QID for 2 days, then as needed
Hydrocodone
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Local AnestheticsMost commonly used: Amides
1. Low toxicity
2. Relative lack of allergenicity
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Local Anesthetics: LidocaineMost used: 2% lidocaine 1/100’000 epinephrine
Medium-duration anesthetic
Two other forms:
1. 1/50’000 epinephrine
2. With no vasoconstrictor (plain)
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Local Anesthetics: MepivacaineVery similar to lidocaine
Usual dosage: 2% 1/20’000 levonordefrin
Also: 3% plain Short procedures
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Local Anesthetics: ArticaineDiffers structurally from other amides;
1. Better lipid solubility Permeability of the lipid barriers
2. Very short half-life (20min); hydrolyzed 90% by plasma esterases (not by liver)
3. Safer for re-injections in long procedures
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Local Anesthetics: Long-acting anestheticsMaximum postoperative pain: First 12 hours
Most common: Bupivacaine (Marcaine)
Amide; Structurally similar to lidocaine and mepivacaine, More potent and less toxic
High pKa (8.1) Lasts 2-3 times longer
1/200’000 epinephrine Limits ability to affect hemostasis
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Local Anesthetics OverdosageMaximum recommended number of anesthetic capsules:
Lidocaine > Mepivacaine > Bupivacaine > Articaine
Amides Special attention to patients with decreased liver function (chronic alcoholism, hepatitis)
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Local Anesthetics OverdosageHalf-life of lidocaine >2.5 times in hepatic patient
Attention to patients with renal and cardiovascular impairment
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Sedative agentsConscious sedation: Minimally depressed level of consciousness that retains the patient ability to independently and continuously maintain an airway and respond appropriately to physical stimulation or verbal command
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BenzodiazepinesMost effective drugs for dental-related anxiety
Depressant effects on the subcortical levels of the CNS
Anxiolysis and anterograde amnesia
Mechanism: unknown; May have an effect on limbic system and thalamus
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Benzodiazepines: Diazepam (valium)Extremely effective if given orally the night before the surgery (5-10mg)
Advantage for dentistry: Reduces salivary flow, Relaxes skeletal muscles
Main disadvantages: 24 hr half-life for adults, 85 hr for elderly
100
Benzodiazepines: Midazolam (Versed)Fast-acting, twice potent as diazepam
Formulated as syrup and inject
Anticonvulsant properties
Excellent muscle relaxant, sedative, amnesic
Should not be combined with other depressants
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Benzodiazepines: Triazolam (Halcion)Short-term hypnotic drug
Orally administered
Fast-acting
Safe and effective for dental procedures (0.25-0.5mg)
Decrease blood pressure by 5 points
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Additional Sedative Anxiolytics: FentanylSynthetic opioid agonist narcotic
Produces analgesia, drowsiness, sedation and euphoria but no amnesia
dose-dependent respiratory depression
Vomiting and nausea (Direct stimulation of dopamine receptors)
103
Additional Sedative Anxiolytics: Propofol (Diprivan)IV sedative-hypnotic agent (Alkylphenol)
Ideal for dentistry; Fast-acting and short half-life (2-24 hours)
Rapidly distributed into peripheral tissues (Short clinical effects)
Respiratory depressant trained individuals
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Reversal AgentsFlumazenil Benzodiazepine antagonist
Rapid onset (1-2min), peak 6-10 min
Recommended dose: 200µg every 1-2 min (Max 3mg/hour)
Repeated dose may be required (short half-life)
105
Reversal AgentsNaloxone (Narcan) Reversal of Narcotic toxicity
IV, acts after 2 minutes, Last about 45 minutes
Many opioids have longer half-life than naloxone Monitor for re-sedation/ respiratory depression of the patient
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THE END107