antibiotics in oral and maxillofacial surgery / orthodontic courses by indian dental academy

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ANTIBIOTICS IN ORAL AND MAXILLOFACIAL SURGERY

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com


• AIM• INTRODUCTION• DEFINITION• HISTORY• CLASSIFICATION• PRINCIPLES FOR CHOOSING ANTIBIOTICS• PRINCIPLES OF ANTIBIOTIC ADMINISTRATION• THERAPEUTIC USES OF ANTIBIOTICS IN ORAL AND MAXILLOFACIAL SURGERY• SPECIAL CONDITIONS• ANTIBIOTIC PROPHYLAXIS IN HEAD AND NECK SURGERY• ANTIBIOTIC MISUSE• ANTIBIOTIC RESISTANCE• CONCLUSION


• AIM• INTRODUCTION


DEFINITION


HISTORY OF ANTIBIOTICS

• 1877 Louis Pasteur

Inhibition of some

microbes by others

• 1908 Gelmo Synthesized

sulfanilamide.


1928 Fleming…Penicillin notatum inhibits growth

‘PENICILLINS’

1941 Chain n FloreyDiscovered properties of penicillin


1932 Domagk Prontosil Therapeutic value sulfonamides

1943, Selman Waksman isolated, Streptomyces griseus …Streptomycin


Mechanism of action


CLASSIFICATIONAntibiotics are broadly classified in to

• Bactericidal antibiotics- they kill bacteria• eg:Cotrimoxazole, fluoroquinolones, penicillins, cephalosporins,

aminoglycosides, vancomycin, teicoplanin

• Bacteriostatic antibiotics- they inhibit bacterial proliferation.• Eg:Sulfonamides, tetracyclines, chloramphenicol

• Erythromycin is bacteriostatic in low doses and bactericidal in higher doses


Based on their mechanism of action antibiotics are classified as

I. Inhibit cell wall synthesis: penicillins, cephalosporins, vancomycin, bacitracin, cycloserine.

II. Damage of cell membrane causing leakage of cell contents: polymixins, amphoterecin B, nystatin.

III. Bind to ribosomes and inhibit protein synthesis: chloramphenicol, tetracyclines, erythromycin, clindamycin, aminoglycosides.

IV. Inhibit DNA gyrase: fluoroquinolones

V . Inhibit DNA function: rifampicin.

VI. Inhibit DNA synthesis: acyclovir, zidovudine.

VII. Interfere with metabolism: sulfonamides, trimethoprim


PRINCIPLES FOR CHOOSING ANTIBIOTICS

• State of host defences• use of least toxic antibiotics• patient drug history• use of bactericidal rather than bacteriostatic

drugs• use of antibiotics with a proven history of

success • cost of antibiotic:


State of host defences

• When a patients defences are impaired ,antibiotics, play a more important role in control of infections.


Determination of Antibiotic sensitivity

• Pencillin Excellent for treatment of• streptococcus infection Erythromycin effective againsstreptococcus,pepto streptococcus, prevotella• Clindamycin good for streptococcus. • Cephalexin Moderate active against • streptococcus, Metronidazole No action against Streptococcus. Excellent activity against anaerobes •


Use of narrow spectrum Antibiotic

• If streptococcus is sensitive to pencillin, cephalosporin and tetracycline , Penicillin should be used because it has narrowest

spectrum.


Use of least toxic antibiotics

• Though chloramphenicol is more effective than penicilin, it is not preferred because of its potential to cause severe bone marrow depression.


Patient drug history

• Two aspects should be reviewed in drug history

→Previous allergic reactions → Previous toxic reactions


Antibiotic Interacting drug Mechanism Effect

Metronidazole Alcohol Inhibition of aldehyde dehydrogenase

Disulfiram reaction

Gentamicin Furosemide Additive Ototoxicity

Metranidazole Warfarin Inhibition of metabolism

Potentiation of anticoagulant

Rifampicin Oestrogens Induction of metabolism

Reduced effects of contraceptive

Rifampicin Warfarin Induction of metabolism

Reduced effects of Warfarin

Tetracyclines Antacids Chelation Reduced effects of Tetracyclinesq

Tetracyclines Warfarin Altered clotting factor activity

Potentiation of anticoagulation


Use of bactericidal rather than bacteriostatic drugs


Use of antibiotics with a proven history of success

• The best evaluation of the efficacy of a drug in a particular situation is the critical observation of its clinical effectiveness over a prolonged period


COST OF ANTIBIOTIC


PREVIOUS ANTIBIOTIC THERAPY

omfs clinics of N.A vol 15 feb 2003


TISSUE DISTRIBUTION OF THE ANTIBIOTIC

• Although abscess cavities are not vascular, some penetration of antibiotic

dose occur.

• Clindamycin best penetrates in to an abscess and attains abscess

concentration of 33% of serum levels. So it may be best in odontogenic

infections.

• Bone penetration of the antibiotics is an important ,especially in

osteomyelitis.

tetracyclins, fluroquinolones, clindamycin best penetrates in to the bone. (omfs clinics of N.A vol 15 feb 2003)


• Cerebrospinal fluid penetration, or ability of an

antibiotic to cross blood-brain barrier, is paramount

in the treatment of infections that threaten the CNS,

as in actual or impending cavernous sinus

thrombosis


PENETRATE B.B.B

1. Penicillins2. Ampicillins3. Ciprofloxacin4. Fluroquinalones5. Metronidazole6. Trimethoprin7. Fluconazole8. acyclovir

DOES NOT PENETRATE B.B.B

1. Cephalosporins2. Clindamycin3. Macrolides4. Aminoglycosides5. Amphotericin6. Ethambutol

(omfs clinics of N.A vol 15 feb 2003)


PRINCIPLES OF ANTIBIOTIC ADMINISTRATION

• Proper dose• Proper time interval• Route of administration• consistency in route of administration


Proper dose

• . Gentamicin is effective in concentrations up to 4-6 microgram/ml but the incidence of nephrotoxicity increases dramatically at 10 microgram/dl plasma level


Proper time interval

• . T1/2 of cefazolin is 2hrs . so interval between doses should be 8hrs


Route of administration

• If given orally, should be given 30mins before or 2 hrs after meals for maximum absorption.

• When long term parenteral administration is necessary IV is preferred over IM as IM is poorly accepted by patient


consistency in route of administration

• “Maintenance of peak blood levels of antibiotics for adequate period is important to achieve maximum tissue penetration and effective bacterial killing”


combination antibiotic therapy

• Indications of combination therapy

If patients condition does not improve after initial therapy????

If initial therapy failed ????


DEVELOPMENT OF ADVERSE REACTIONS

• Antibiotic associated collitis: treatment: discontinue antibiotic vancomycin and metranidazole.

• Super infection and recurrent infection:


THERAPEUTIC USES OF ANTIBIOTICS IN ORAL AND MAXILLOFACIAL SURGERY


• MOENING(1989) “It would seem presumptuous to state that

penicillin is currently not effective against most odontogenic infections and premature to consider substituting another antibiotic as the drug of choice for mild to moderate odontogenic infection especially when low cost and lack of toxicity is considered.”


ABSCESS

Penicillin is the drug of choice


PERICORONITIS

Penicillin is the drug of choice


ODONTOGENIC INFECTIONS AND DEEP FASCIAL

SPACE INFECTIONS OF DENTAL ORIGIN:• Penicillin+Metranidazole• Azithromycin is better than Erythromycin• Amoxicillin + Clavulanic acid→ severe infections• Minocycline or Doxycycline→ low grade infections


• For immunocompromised or hospitalized patients:

CLINDAMYCIN alone (or) CLINDAMYCIN+METRONIDAZOLE (or) GENTAMICIN (or) PARENTERAL AMPICILLIN+SULBACTUM


SALIVARY GLAND INFECTIONS:

• Out patient- amoxicillin+clavulanic acid• In patient- ampicillin+sulbactum(parenteral)• In case of penicillin allergy clindamycin is used


OSTEOMYELITIS

• causative organisms are staphylococcus

epidermis, hemolytic streptococci, prevotella,

porphyromonas


Regimen 1: for hospitalized /medically compromised patient or when IV therapy is

indicated• Aq penicillin 2 million units IV 4 hrly , metronidazole 500mg 6 hrly

• When improved for 48-72hrs, switch to penicillin V 500mg per oral 4 hrly

plus metronidazole 500mg per oral 6 hrly for an additional 4-6 weeks.

• Ampicillin/sulbactum 1.5 -3 gms IV 6hrly, when improved for 48-72 hrs

switch to amoxicillin/clavunate 875/125 mg per oral bid for an additional

4-6 weeks.


Regimen 2: for out patient treatment

• PenicillinV 2gm plus metronidazole 0.5 gm 8hrly per oral for 2-4

weeks after last sequestrum removed and patient without

symptoms.

• Clindamycin 600-900mg 6hrly IV then clindamycin 300-450mg

6hrly per oral.

• Cefoxitin 1.0 gm 8hrly IV or 2gm 4hrly IM or IV until no

symptoms, then switch to cephalexin 500mg 6hrly per oral for 2-4

days.


• Penicillin allergy-clindamycin and cefoxitin• Macrolides are not recommended


CHRONIC SUPPURATIVE OSTEOMYELITIS

Treatment should begin with IV therapy and continue even after discharge using home IV therapy usually with ampicillin/salbactum sodium because it is stable for 24hrs after mixing with IV fluids. IV therapy for 2 weeks or until the patient has shown improvement for 48-72 hrs. Oral therapy should be continued for 4-6 weeks after patient has no symptoms or from the date of last debridement


• If ampicillin/sulbactum sodium is ineffective clindamycin therapy is indicated


• Antibiotic impregnated beads :

eg: tobramycin or gentamicin in acrylic resin bone cement beads. They are removed after 10-14 days


SPECIAL CONDITIONS


SAFE RELATIVELY SAFE AVOID

PENICILLIN METRANIDAZOLE TETRACYCLINES

CEPHALOSPORINS CHLORAMPHENICOL

AZITHROMYCIN SULPHANAMIDES

CLINDAMYCIN AMINOGLYCOSIDES

CLOTRIMOXAZOLE

PREGNANCY


CHILDREN

• Tetracyclines – permmenant intrinsic dental staining• Fluoroquinolones- chondrotoxicity in growing cortilage• Carbapenems, imipenem- risk of seizures

(omfs clinics of N.A vol 15 feb 2003)


LIVER DISEASES

To be avoided1. Tetracyclines2. Erythromycin 3. talampicilin

preferable1. amoxicillin


Safe fairly safe less safe avoidCloxacillinerythromycinKetoconazolerifampicin

AmpicillinAmoxicillinClindamycinmetronidazole

AminoglycosideCphalosporinsFluconazolevancomycin

SulphonamidesCephaloridineCephalothintetracycline

Safe - no dosage change usually neededFairly safe - dosage change only in sever renal failure.Less safe - dosage reduction is neededAvoid - in all the patents

CHRONIC RENAL FAILURE


ANTIBIOTIC PROPHYLAXIS IN HEAD AND NECK SURGERY

ADVANTAGES

DIS ADVANTAGES


PRINCIPLES

1.RISK OF INFECTION MUST BE SIGNIFICANT

2.CHOOSE CORRECT ANTIBIOTIC

3.ANTIBIOTIC PLASMA LEVELS MUST BE HIGH

4.ANTIBIOTIC MUST BE TIMED CORRECTLY

5.USE SHORTEST ANTIBIOTIC EXPOSURE THAT IS EFECTIVE


RISK OF INFECTION MUST BE SIGNIFICANT

• a) Bacterial inoculums should be sufficient size to cause infection.

• b) Prolonged and extensive surgery.• c)Presence of foreign body


• .CHOOSE CORRECT ANTIBIOTIC:• a) Antibiotic must be effective against• causative organism.• b) Choose narrow spectrum antibiotic• c) It should be least toxic• d) Select bactericidal antibiotic


• ANTIBIOTIC PLASMA LEVELS MUST BE HIGH:• a) Prophylactic doses should be higher

than therapeutic doses• b) Antibiotic should diffuse into all fluids

and tissue spaces where surgery is going on.• c) Doses should be at least two times the

therapeutic dose.


• penicillin-1gm Cephalosporins-1gm• Clindamycin-300m • Clarithromycin-500mg


ANTIBIOTIC MUST BE TIMED CORRECTLY

• penicillin should be given every 2 hrs.• Cephalexin should be given every 2 hrs• Clindamycin should be given every 3 hrs


USE SHORTEST ANTIBIOTIC EXPOSURE THAT IS EFECTIVE


ANTIBIOTIC PROPHYLAXIS OF WOUND INFECTION:

1.PARENTERAL REGIMEN: 1. Penicillin:• Preoperative 1 million units IV• Intraoperative 1 million units IV q2hrs• Post operative 1 million units IV in recovery room 2.Cephazolin(penicillin allergic patients)• Preoperatively 1gm IV• Intraoperatively 1gm Ivq 4h• Postoperatively 1gm IV in recovery room.


• 3.Clindamycin• Preoperatively 600mg IV• Intraoperatively 600mg IV 4h• Post operatively 600mg IV in recovery room


2.ORAL REGIMEN: 1.Penicillin• Preoperative 2mg po 30min before• Intraoperative 1mg per oral 2hrly• Post operative 1mg per oral 2hrly 2. Erythromycin• Preoperative 1gm 1hr before• Intraoperative 500mg per oral 2hrs• Post operative 500mg peroral 2hrs


ORTHOGNATHIC SURGERY

rapid I.V administration of penicillin G 600,00 U achieves a peak

of 7micro.gm/ml, which is greater than 3 to 4 times more

than the MIC for susceptible organisms.

• penicillin should be given parenterally in dose of 1 or 2 million

U preoperatively and an additional dose every 11/2 to 2 hrs.

least A.B dose should be given in recovery room.

• it can prevent prolonged use of antibiotics• joms vol 49 1991


ANTIBIOTIC MISUSE

PREVENTION


ANTIBIOTIC RESISTANCE:

• MULTIPLE DRUG RESISTANT ORGANISMS• VRE- Vancomycin resistant enterococci

• MRSA- methicillin/oxacillin resistant staphylococcus aureus

• ESBLs-extended spectrum beta lactamases(which are resistant to cephalosporins and monobactams)

• PRSP-Penicillin resistant streptococcus pneumoniae


• PREVENTION:


• CONCLUSION:


REFERENCES

• Oral and maxillofacial infections-topazian• Contemporary oral and maxillofacial surgery-peerson• Pharmacology and pharmacotherepeutics-satoskar• Davidson’s principles and practice of medicine• Oral and maxillo facial surgery-daniel.m.laskin• OMFS clinics of n.a vol 15 feb 2003• Peterson L. Antibiotic prophylaxis against wound infections in oral and

maxillofacial surgery. J Oral Maxillofac Surg 1990;48:617-20.• Antibiotic prophylaxis in Oral and Maxillofacial Surgery. Med Oral Patol Oral

Cir Bucal 2006;11:E292-6.


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