antibiotics in oral and maxillofacial surgery

1. ANTIBIOTICS IN ORAL &
MAXILLOFACIAL SURGERY
Guided by :
Dr. KAVITA RAGHOTAM
Presented by : VINAYAKA T

2. cCONTENTS
INTRODUCTION
HISTORY
CLASSIFICATION
PRINCIPLES OF CHOOSING ANTIBIOTICS
PRINCIPLES OF ADMINISTRATION
ADVERSE REACTION
CONCLUSION
REFERENCES

3. ANTIBIOTICS
• These are substances produced by
microorganisms which suppress the growth
or kill other microorganisms at very low
concentrations
• The term antibiotic means "against life".

4. History of chemotherapy
DOMAGK the modern era of chemotherapy: started by the
use of PRONTOSIL a sulfonamide dye .
PASTEUR demonstrated the phenomenon of ANTIBIOSIS –
growth of anthrax bacilli in urine was inhibited by airborne
bacteria.
Term antibiosis given by Jean Paul Vuillemin 1877
Renamed as Antibiotics by Selman waksman 1942

5. • FLEMMING found a substance formed from
the pencillium mould could destroy
staphylococcus on the culture plate.
• In the past 50 years emphasis has shifted from
searching newer antibiotic organism to
developing semi synthetic derivatives of older
antibiotics

6. • Classification
1.Based on chemical structure
• Quinolones
• Beta lactam antibiotics
• Aminoglycosides
• Macrolides
• Nitro- imidazoles
• Sulfonamides
• Glycopeptides
• Others
2.Based on mechanism of action
• Inhibit cell wall synthesis
• Inhibit protien synthesis
• Interfere with DNA function
• Cause misreading of m-RNA code & affect permeability
• Inhibit DNA Gyrase enzyme
• Interfere with intermediary metabolism

7. 3. Spectrum of activity
• NARROW SPECTRUM:
PENCILLIN G
ERYTHROMYCIN
• BROAD SPECTRUM:
TETRACYCLINE
CHLORAMPHENICOL
• EXTENDED SPECTRUM:
SEMISYNTHETIC PENCILLIN,
CEPHALOSPORINS,AMINOGLYCOSIDES.

8. 4.Based on type of organism against which the
drug is primarily active against:
• Anti bacterial
• Anti viral
• Anti fungal
• Anti protozoal
• Anti helmenthic

9. 5. Type of action
• Bacteriostatic: sulfonamides
tetracyclines ,
erythromycin .
• Bactericidal: penicillin ,
ciprofloxacin
cephalosporin.
6. Source
• Fungi: penicillin, cephalosporin.
• Bacteria: polymyxin, bacitracin.
• Actinomycetes: aminoglycosides,
macrolides, tetracyclines, chloramphenicol.

11. PRINCIPLES OF PROPHYLACTIC ANTIBIOTIC USE
1. PROCEDURE SHOULD HAVE SIGNIFICANT RISK OF INFECTION
2. CHOOSE CORRECT ANTIBIOTIC
3. ANTIBIOTIC PLASMA LEVEL MUST BE HIGH
4. TIME ANTIBIOTIC ADMINISTRATION CORRECTLY
5. USE SHORTEST ANTIBIOTIC EXPOSURE THAT IS EFFECTIVE

13. Prescribe or administer sufficient amounts to achieve the
desired therapeutic effect but not enough to cause injury to the host.
- For therapeutic purposes the peak concentration of the antibiotic at the
site of infection should be 3 – 4 times the MIC.
- Administration of doses above that level increases the likelihood of
toxicity .
- Subtherapeutic levels may mask an infection.
- Each antibiotic has an established plasma half life , during which ½ of the
absorb drug is excreted.
- Usual dosage interval for the therapeutic use of antibiotics is 4 times the
t½.
- At 5 times the t½, 95% of the drug has been excreted.
1. Proper dose:
2. Proper time interval:
PRINCIPLES OF ANTIBIOTIC
ADMINISTRATION

14. -In some infections, only parental administration produces the necessary
serum level of antibiotics
-Oral route results in the most variable absorption.
-Most antibiotics should be taken at in fasting state ( 30mins before or 2 hrs
after meal) for maximum absorption.
-When treating a serious, established infection, parental antibiotic therapy is frequently
MOC.
-Recurrence of infection is more likely by switching from parenteral to oral
route on the 2nd or 3rd day of antibiotic therapy.
-After 5th day of parental administration , the blood levels achievable with
oral administration are usually sufficient.
3. Proper route of administration:
4. Consistency in route of administration

16. Problems with use of AMA
Felix Marti-Ibanez, 1955.

17. Drug resistance
• Natural resistance: some microbes are
naturally resistant to certain drugs their
metabolic process or target site is unaffected
by this drug.
• Acquired resistance: development of
resistance over a period of time
1. mutation
2. Gene transfer (horizontal evolution).

18. • Mutation
It is stable & heritable genetic change
that occurs spontaneously & randomly
among m-osms
1. Single step
2. Multi step
• Gene transfer from one organism to another
1. conjugation: gram -ve
2. transduction: bacteriophage
3. transformation:

20. • The resistant m-osms may be,
• Drug tolerant: loss of affinity of the target
biomolecule of m-osms
• Drug destroying: elaborate an enzyme which
inactivates the drug
• Drug impermeable: transport mechanism may
be lost

21. TOXICITY
• A) Local irritancy: pain
gastric irritation ,
• B) Systemic toxicity: dose related
• Aminoglycosides : 8th nerve toxicity-kidney
toxicity.
• Tetracyclines: liver and kidney damage,anti-
anabolic effect.
• Chloramphenicol: bone marrow depression.

22. Hypersensitivity reactions
• These are unpredictable and unrelated to
dose whole range of reactions from rashes to
anaphylactic reactions can be produced.
Superinfection
• The use of antibiotics cause alteration in the
normal microbial flora. The normal microbial
flora contributes to host defence by producing
substances called BACTERIOCINS.
• Common when host defence is compromised

23. Nutritional deficiencies
• Vit B complex and Vit K synthesised by
intestinal flora
• Prolonged use of antimicrobials disrupt this
flora

24. Choice of an antibiotic
• Patient factors
• Organism related consideration
• Drug factors

25. Combined use of antimicrobials
• To achieve synergism
• To reduce severity or incidence of adverse affects
• To prevent emergence of resistance
• To broaden spectrum of anti microbial action
Disadvantages
• Toxicity of one agent may be enhanced by other
• Increased chances of suprainfections
• Inadequate doses of non-synergistic drugs causes emergence of
resistant strains
• Increased cost of therapy

26. Failure of chemotherapy
• Improper selection of drug
• Treatment begun too late
• Failure to take necessary adjuvant measures ;
drainage of abscess, empyema.
• Poor host defence – as in leukemia
neutropenia.

27. PHARMACOLOGY

28. Sulfonamides
• Sulfonamides are the anti-bacterial agent
active against pyogenic bacterial infections .
• Bacteriostatic act by interfering with bacterial
synthesis of folic acid
• Active against many gram+ve and gram- ve
organisms
• Nausea, vomitting, crystalluria.

29. Sulfonamides
Preparations available and dosage regimens
Short-acting:
• Sulfisoxazole is excreted rapidly, is soluble in
urine, and still is occasionally used in UTIs.
• Sulfadiazine is less soluble in urine and
therefore less suitable for use in UTI

30. Sulfonamides
Intermediate-acting sulfonamides:
• Sulfamethoxazole has been combined with trimethoprim and
is available as cotrimoxazole.
• Oral. Single-strength (SS) tablets contain 80 mg TMP and 400
mg SMX. The double-strength (DS) tablets contain 160 mg of
TMP and 800 mg SMX.
• Parenteral. An intravenous form of TMP-SMX is supplied in 5-
ml ampules that contain 80 mg TMP and 400 mg SMX.
Long-acting sulfonamides are no longer recommended

31. Quinolones
• Entirely synthetic antimicrobial
• Mainly active against Gram-ve bacteria, though newer type like
flouroquinalones are active against gram positive organisms
• Inhibit the bacterial DNA gyrase & thus inhibit the supercoiling of DNA,
hence bactericidal
Classification
First generation:
nalidixic acid
Second generation:
Ciproflox Norflox Lomeflox Oflox
Third generation:
sparflox Gatiflox Grepaflox
Fourth generation:
trovafloxacin

32. PENICLILLINS
• Mechanism of action:
• Inhibit transpeptidases which prevents the peptidoglycan cross
linking in bacterial cell wall in actively dividing cells, thus causing
abnormal cell wall development.
• The efficacy of penicillins is maximum when there is active cell
wall synthesis, hence do not combine bacteriostatic agent with
penicillins.
• Less effective against gram –ve organisms as they lack cell wall.
• As cell wall is uniquely a bacterial feature not found in humans, it is
this reason why penicillins are virtually nontoxic to humans.

33. Parenteral preparations of penicillin G :
• AQUEOUS PENICILLIN G : 3 to 4million units q4hr. (children 25,000 to3,
00,000 units/kg/day)
• PROCAIN PENICILLIN G : 3,00,000 to 6,00,000 units IM 12hr
• BENZATHINE PENICILLIN G :0.6-2.4MU i.m every 2wks as aqueous
suspension
Semi synthetic penicillin
• Acid resistant:
– phenoxy methyl penicillin (penicillin V).
• Penicillinase resistant penicillin:
– methicilllin , cloxacillin.
• Extended spectrum:
1. Aminopenicillin: Amoxycillin, Ampicilllin.
2. Carboxy Penicillins: Carbencillin
3. Ureidopenicillins: Piperacillin
• Beta lactamase inhibitor :
– clavulanic acid , sulbactam.
Newer beta-lactam drugs
Aztreonam , Imipenem

34. Cephalosporins
Parenteral Oral
1st generation Cephalothin
Cefazolin
Cephapirin
Cephradine
Cephalexin
Cephradine
Cephadroxil
2nd generation Cefamandole
Cefoxitin
Cefotetan
cefuroxime
Cefuroxime axetil
Cefprozil
Cefaclor
Loracarbef
3rd generation Cefotaxime
Cefoperazone
Cefuroxime
Ceftizoxime
Ceftriaxone
Ceftazidime
Cefixime
Cefpodoxime proxetil
Ceftibuten
Cefdinir
4th generation Cefepime
Cefpirome

35. Macrolide antibiotics
Erythromycin
Clarithromycin
Azithromycin
Azithromycin:
• Azithromycin is a newer macrolide developed to overcome some of the
shortcomings of erythromycin such as GI intolerance, low bioavailability,
and somewhat limited spectrum of activity.
Dosage
1. Azithromycin is available as a 250 mg tablet (or capsule) commonly
distributed in a “Z-pack” containing six tablets for a standard 5-day regimen
in adults (two tablets [500 mg] day 1 and then one 250 mg tablet qd days 2
to 5). Tablets can be taken with or without food.
2. The flavored oral suspension comes in 100-mg/5 ml and 200-mg/5 ml. The
suspension should be given 1 hour before or 1 hour after meal.
5. For IV azithromycin 500 mg IV once daily is infused over at least 60 minutes
in patients 16 years of age and older

36. Tetracycline

37. AMINOGLYCOSIDES
• Streptomycin
• Amikacin
• Gentamicin
is used in combination with another agent to achieve synergy against certain
pathogens:
I. With penicillin, ampicillin, or vancomycin against gentamicin-
susceptible enterococci or viridans streptococci;
II. With ampicillin against listeria monocytogenes;
III. In conjunction with ampicillin (or vancomycin) for endocarditis
prophylaxis in high-risk patients before genitourinary (GU) or
gastrointestinal (GI) procedures;
IV. Combined with an antistaphylococcal penicillin for right-sided
endocarditis caused by S. Aureus. Gentamicin is the preferred
aminoglycoside in combination therapy aimed at enterococci.
Amikacin has been used in some atypical mycobacterial infections.
Streptomycin remains a useful agent for M. tuberculosis therapy and for M.
kansasii infections.

38. Vancomycin
Active against resistant organisms
Not well absorbed orally .
Inhibits bacterial cell wall synthesis
Clindamycin
Oral absorption is good.
It penetrates to most skeletal and soft tissues.
Pseudomemberaneus enterocollitis superinfection due to
clostridium difficle.

39. Metronidazole
1. Metronidazole is very active and bactericidal
against anaerobes, especially gram-negative
anaerobes, including Bacteroides fragilis, other
Bacteroides spp., and Fusobacterium spp.
Clostridium spp., including C.perfringens and
C.difficile are susceptible to metronidazole
2. The activity of metronidazole against anaerobic
gram-positive cocci is much more variable with
resistance in up to half of tested isolates
3. Strains of Actinomyces and Propionibacterium
(e.g., P.acnes) are resistant Parasites.
Metronidazole is very active against Entamoeba
histolytica, Giardia lamblia, and Tricahomonas
vaginalis

40. NEW ANTIBIOTICS OF INTEREST TO ORAL AND
MAXILLOFACIAL SURGEONS
Moxifloxacin And Gemifloxacin
LINEZOLID
Approved by FDA for infections caused by vancomycin resistant E. faecium,
nosocomial pneumonia caused by MRSA
Dose : 600mg BD for Enterococci
Quinupristin / dalfopristin
Daptomycin
Otravacin
Remoplanin
Tigilcycline

42. PREGNANCY RISK CATEGORIES OF SELECTED
ANTIBIOTICS
ANTIBIOTIC PREGNANCY RISK
CATEGORY
PREGNANCY RISK
PENICILLINS
PENICILLIN G AND V
AMPICILLIN
AMOXICILLIN
AMOX + CLAVUNATE
TICARCILLIN +
CLAVUNATE
B
CEPHALOSPORINS
CEPHALEXIN
CEFAZOLIN
CEFACLOR
CEFOTAXIME
B
ANTIANEROBIC
CLINDAMYCIN
METRONIDAZOLE
B

43. FLUOROQUINOLONES
CIPROFLOXACIN
MOXIFLOXCIN
C
SPONTANEOUS
ABORTIONS IN RABBITS
FETAL TOXICITY IN
RODENTS AND MONKEYS
AMINOGLYCOSIDES
GENTAMICIN
TOBRMYCIN
D OTOTOXICITY IN HUMAN
FETUSES
MACROLIDES
ERYTHROMYCIN
CLARITHROMYCIN
AZITHROMYCIN
B
C
B
FETAL DEFECTS IN MICE
AND MONKEYS
OTHER
VANCOMYCIN
TETRACYCLINES
DOXYCYCLINE
LINEZOLID
C
D
D
C
OTOTOXICITY IN FETUSES
INTRINSIC DENTAL
STAINING
FETAL TOXICITY IN
RODENTS

44. Antibiotic Second drug Adverse effects Mechanism
Erythromycin E
Clarithromycin C
Theophylline Seizures ,
dysrhythmias
Inhibits
cytochrome P 450
metabolism of 2nd
drug
Carbamazepine Ataxia, vertigo,
drowsiness
Methylprednisolo
ne immunosuppressi
on
Erythromycin Clindamycin antibiotic effect Mutual
antagonism
Erythromycin E
Clarithromycin C
Metronidazole
warfarin
anticoagulation
Interferes with
the metabolism
Cephalosporin Aminoglycosides nephrotoxicity Additive effect
Drug interactions

45. Tetracycline ,
Cefotetan,
Cefoperazone ,
Aminoglycosides,
sulfonamides
Warfarin
anticoagulation
Antibiotic kills gut
flora that
synthesize vit k ,
which antagonizes
the 2nd drug
Penicillins ,
cephalosporins
Metronidazole
Erythromycin
Tetracyclines
Estrogen and
progestin
containing oral
contraceptives
Contraceptive
failure
Interference with
enterohepatic
circulation of
estrogen caused by
killing of gut flora
Fluoroquinolones
Sulfonamides
Chloramphenicol
Oral hypoglycemic
agents
Hypoglycemia Antibiotic displaces
2nd drug from
plasma proteins
Ciprofloxacin
sulfonamides
Chloramphenicol
Phenytoin Increases serum
level of phenytoin ,
confusion, delirum
Interference with
phenytoin
metabolism

46. PRIMARY REASONS FOR REVISION OF THE INFECTIVE
ENDOCARDITIS PROPHYLAXIS GUIDELINES
Infective endocarditis (IE) is much more likely to result from frequent
exposure to random bacteremias associated with daily activities than from
bacteremia caused by a dental,GI tract or genitourinary (GU) tract
Procedure
Prophylaxis may prevent an exceedingly small number of cases of IE, if any, in
people who undergo a dental, GI tract or GU tract procedure
The risk of antibiotic-associated adverse events exceeds the benefit, if any,
from prophylactic antibiotic therapy
Maintenance of optimal oral health and hygiene may reduce the incidence of
bacteremia from daily activities and is more important than prophylactic
antibiotics for a dental procedure to reduce the risk of IE

47. Previously/No longer recommended Currently recommended
Mitral valve prolapse.
Rheumatic heart disease.
Bicuspid valve disease.
Congenital heart conditions (eg atrial septal
defect, ventricular septal defect, hypertrophic
cardiomyopathy).
Calcified aortic stenosis
Patients with history of previous IE
 Patients with a prosthetic cardiac valve
Recipients of cardiac transplantation who
develop cardiac valvulopathy
Patients suffering from the following forms of
congenital heart disease (CHD).
Completely repaired CHD with prosthetic
device or material during the first
six months following the procedure where
placement is either by surgery or catheter.
Unrepaired cyanotic CHD, which includes
palliative shunts and conduits.
Repaired CHD with residual defects at or
adjacent to the site of a prosthetic
device or patch (inhibiting
endothelialization).
Antibiotic therapy is no longer
recommended for any other form of CHD
other than those named above.

48. Current recommended regimens for dental procedure
Patient Antibiotic One dose 30–60 min before procedure
Adults Children
Able to take oral
medication
Amoxicillin 2 gm 50 mg/kg
Not able to take
oral medications
Ampicillin
Cefazolin
Ceftriaxone
2 g IM or IV
1 g IM or IV
50 mg/kg IM or IV
50 mg/kg IM or IV
Allergy to Penicillins
or ampicillin oral
Cephalexin*
Clindamycin
Azithromycin
Clarithromycin
2 g
600 mg
500 mg
50 mg/kg
20 mg/kg
15 mg/kg
Allergy to penicillins
or ampicillin and
not able to take oral
medications
Cefazolin
Ceftriaxone
Clindamycin
1 g IM or IV
600 mg IM or IV
50 mg/kg IM or IV
20 mg/kg IM or IV
*Do not use cephalosporins in patients with a history of
anaphylaxis, angioedema, or urticaria with penicillins or ampicillin

49. TOTAL JOINT REPLACEMENT
Procedures – requiring prophylaxis
Dental extractions
Periodontal procedures, scaling n root planing
Dental implant
Periapical endodontic procedures
Intraligamentary LA
Placement of orthodontic bands
ADA and AAOS most pts with a prosthetic joint are not at
risk of joint infection after a dental surgical procedure.

50. EXODONTIA AND DENTOALVEOLAR SURGERY
• Although intraoral surgical wounds are contaminated by the oral flora, the
ability of patients normally to tolerate this bacterial population and the
excellent blood supply to the oral tissues allow such wounds to be managed
similarly to clean wounds. It is unnecessary to use prophylactic antibiotics
to prevent infection when performing most types of exodontia and
dentoalveolar surgery unless there are other contributing risk factors.
• If the procedure involves the maxillary sinus or nasal cavity, however, this
can result in cross-contamination with new organisms, and prophylactic
antibiotics should be used except when there is already infection in these
areas. In the latter instance, therapeutic antibiotics are indicated.

51. IMPACTED THIRD MOLAR SURGERY
• Although many practitioners routinely prescribe antibiotics for patients
who have impacted third molars removed, they are generally prescribed
postoperatively. No convincing data show a significant reduction in
postoperative infections after third molar removal when antibiotics are used
in this manner.
• Prophylactic antibiotics treatment should be reserved only for patients with
significant medical risk factors for infection. In these cases it should be
given immediately before surgery, having a high tissue concentration
present at the time of surgery when the wound is exposed to bacterial
contamination, and for 3 to 5 days after surgery to provide an adequate
period of coverage.

53. Oro facial infections

54. Osteomyelitis
Antibiotic
impregnated beads
Tobramycin and
gentamicin in
acrylic resin bone
cement beads
They are removed
after 10-14 days.

56. ORTHOGNATHIC SURGERY
• Orthognathic surgery performed via an extraoral approach is
considered a clean procedure and prophylactic antibiotics
should not be necessary unless communication with the mouth
is anticipated.
• Intraoral procedures and procedures that involve the maxillary
sinus and nasal passages are clean-contaminated operations,
and short-term prophylactic antibiotics have been shown to
reduce the postoperative infection rate.

57. MANDIBULAR FRACTURES
• Patients with condylar process fractures treated by either open or closed reduction
require no prophylactic antibiotics. The same is true for fractures in other non–
tooth-bearing areas that are not in communication with the mouth, because these are
all clean wounds.
• In patients with compound mandibular fractures, however, which are contaminated
wounds, studies have shown that the use of antibiotics is effective in reducing
postoperative infections.
• Fractures for which there is delayed treatment should be considered dirty wounds,
and such patients should receive therapeutic antibiotics postoperatively

58. In relation to trauma and Soft tissue injury
• Not indicated when the patient is first
seen in the ED, for laceration wounds which are
 not extensive
 visibly clean
 treated early
• Indicated when the patient is first seen in the ED,
for laceration wounds which are extensive
• For extensive laceration wounds seen early, in
which a delay in treatment is expected,
prophylactic antibiotics should be started
immediately and continued until definitive
treatment
• Laceration wounds seen late or wounds which are
visibly contaminated should be assumed to be
infected
Open fractures of the facial bones
• Antibiotic prophylaxis is indicated and
should be administered
when the patient is first seen in the
Emergency Department
• When a delay in treatment for open
fractures is expected
antibiotics should be started on admission
and continued until
temporary or definitive fixation of the
fractures
• Open fractures that are seen late should
be assumed to be infected
• Antibiotic prophylaxis is indicated in the
surgical management
of open fractures of the facial bones

59. Dental implants

61. References
• ORAL AND MAXILLOFACIAL INFECTIONS – TOPAZIAN
• Essentials of Medical Pharmacology- K D Tripathi
• Basic & Clinical Pharmacology- Katzung
• Articles from internet – sciendirect.com
Infections are ultimately cured by the
host and not the antibiotic !
- Topazian

62. Thank you
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