This PowerPoint presentation offers a concise yet technical overview of antibiotic therapy. Dive into antibiotic mechanisms, classifications, indications, and prudent use. Master essential aspects of antibiotic therapy for informed clinical decision-making.

1. PRINCIPLES OF
ANTIBIOTIC THERAPY
Dr. Sneha Rathee
Post Graduate III
Oral and Maxillofacial Surgery

2. CONTENTS
Introduction
Principles of antibiotic therapy
Implications in oral &
maxillofacial surgery
Antibiotic prophylaxis
2

3. INTRODUCTION
Antibiotic:-
A substance produced by microorganisms, which suppresses or
inhibits the growth of other microorganisms at very low
concentrations.
3

4. Antimicrobials- This term refers to both antibiotics and
synthetic agents active against microbes
Bactericidal- organism is lysed or killed by direct damage on
susceptible cell target
Bacteriostatic- these agents exert their influence by inhibiting
growth and reproduction of the bacteria usually by inhibiting
protein synthesis
4

5. 5

6. CATEGORIES OF ANTIBIOTIC THERAPY
No
infection
Infection Symptoms Pathogen
isolation
Resolution
Prophylaxis Empiric Definitive Suppressive
6

7. CLASSIFICATION OF ANTIBIOTIC
THERAPY-
TYPE DEFNITION EXAMPLE
Prophylactic Principle- Targeted therapy, preserve the native bio as much as possible.
Narrow spectrum antibiotics / short duration of time, during which maximum
contamination is expected, to prevent infection and to prevent development of a
potentially dangerous disease. The antibiotic must be administered in a proper
manner so that antibiotic level should be high and use of the shortest effective
antibiotic exposure is preferred
SBE prophylaxis, post
exposure prophylaxis
Empirical Directed against an anticipated and likely cause of infectious disease. Broad
spectrum antibiotics are usually prescribed when the bacterial infection is
suspected but the group of bacteria is unknown.
Augmentin +
metronidazole given to
a space infection patient
Definitive Once a pathogen is identified and susceptibility results are available, therapy is
streamlined to a narrow targeted antibiotic to decrease the risk of antibiotic
toxicity and selection of antimicrobial resistant pathogen. Proper antimicrobial
doses and dose schedules are crucial to maximize efficacy and to minimize toxicity.
Suppressive Used in some patients when the infection is controlled but not completely
eradicated, and the immunological or anatomical defect that led to the original
infection is still present. Therapy is usually continued at a much lower dose for a
longer duration of time
Minocycline and
clindamycin used in
patients with prosthetic
joint infections.
7

8. PRINCIPLES OF ANTIBIOTIC
THERAPY
• Principle 1- to determine the presence of
infection
• Principle 2- to evaluate state of patients host
defence mechanism
• Principle 3- surgical drainage and incision
• Principle 4- the decision to use antibiotic therapy
8

9. An appropriate decision about whether antibiotic
therapy is necessary or not will depend on factors
like:
A) THE PRESENCE OF INFECTION:
Local
Systemic
9

10. Signs of infection-
Local- pain, swelling, surface erythema, pus formation
and limitation of motion
Systemic- fever, lymphadenopathy, malaise, toxic
appearance and elevated WBC
Non-infectious conditions mimicking infectious
conditions (are to be carefully diagnosed):
1. Pulpitis
2. Removal of 3rd molar(2nd day)
3. Major maxillofacial procedures performed under GA
10

11. B) STATE OF HOST DEFENSES:
• Host defence mechanism are the most important
factor in the final outcome of bacterial insults
• Inflammatory response with its migration of WBC
and production of antibodies provides most of this
protection
• If this mechanism is impaired the infection will
result from an otherwise minor bacterial exposure
11

12. Causes of depressed host defenses:
1. Physiological
2. Disease related
3. Defective immune system related
4. Drug suppression related
12

13. Causes of depressed host defenses:
1. Physiological
• Patients inability to deliver the defending agents-
WBC, antibodies, complements to the site of
bacterial invasion
• shock, disturbances in circulation caused in old
ages or obesity and fluid imbalances.
13

14. Causes of depressed host defenses:
2. Disease related
• Malnutrition syndrome (alcoholism),
cancers, leukemia, poorly controlled
diabetics.
14

15. Causes of depressed host defenses:
3. Defective immune system related
congenital defects such as
• agammaglobulinemia,
• multiple myeloma,
• total body irradiation therapy,
• children who have had splenectomy-
pneumonia, streptococcal pneumoniae
15

16. Causes of depressed host defenses:
4. Drug suppression related
• cytotoxic drugs in malignancies
• Immunosuppressive drugs- glucocorticoids,
azathioprine and cyclosporine
16

17. C) INCISION & DRAINAGE
Deep tissue/space infection
• Extraction of the affected tooth
• Intra/extra-oral incision and drainage with placement of
drain
Cellulitis
• Incision- faster resolution, increased vascular flow, better
perfusion of antibiotics
• If unrelieved, compromised vascularity prevents host
defenses from reaching the target area
17

18. D) DECISION TO USE ANTIBIOTIC
THERAPY
• Carefully weigh the risk to benefit ratio before
administering the antibiotic
• Risks- allergy, idiosyncratic reactions, super-
infections from non-pathogenic bacteria, antibiotic
resistance
• Minor infection with intact host defences- avoid
antibiotics
• Moderate infection with intact host defences- I&D
• Compromised host immunity- antibitoics &/or
I&D
18

19. SELECTING THE
APPROPRIATE ANTIBIOTIC
Some of the guide lines which can be helpful in antibiotic
selection are:
19

20. A. IDENTIFICATION OF CAUSATIVE
ORGANISM
The typical odontogenic infection is caused by a mixture of
aerobic and anaerobic bacteria.
Approximately 70%-mixed flora
5%-pure aerobic
25%-pure anaerobic
21

21. A. IDENTIFICATION OF CAUSATIVE
ORGANISM
• Initial/Emperical therapy- can be started when the clinical
course of infection is known
• Initial empirical therapy may be instituted with a fair
degree of reliability if the following criteria are met-
1. The site and features of the infection have been well
defined
2. The circumstances leading to the infection and the
organism that most commonly cause such infections is
known
22

22. Type of
infection
Microorganisms
Odontogenic
cellulitis/abscess
Streptococcus milleri group
Peptostreptococci
Prevotella and Porphyromonas
Fusobacteria
Rhino-sinusitis Acute Streptococcus pneumoniae
Haemophilus influenzae
Head and neck anaerobes (Peptostreptococci,
Prevotella, Porphyromonas, Fusobacteria)
Group A beta-hemolytic streptococci
Staphylococcus aureus
Moraxhella catarrhalis
Viruses
Chronic Head and neck anaerobes
Fungal Aspergillus
Rhizopus sp. (mucormycosis)
Nosocomial
(especially if
intubated)
Enterobacteriaceae (especially Pseudomonas,
Acinetobacter, Escherichia coli)
S. Aureus
Yeasts (Candida species)
Major pathogens of head and neck infections
23

23. Osteomyelitis of the
jaws
Acute Odontogenic flora
S. aureus and skin flora in trauma
Salmonella .
Chronic Actinomyces species
Necrotizing fasciitis Group A beta-hemolytic streptococci
Regional flora (oral and sinus pathogens in
head and neck)
Fungal Mucosal or
disseminated
Candida species
Soft tissue Histoplasma species
Blastomyces species
Sinus Aspergillus
Rhizopus (mucormycosis)
Major pathogens of head and neck infections
24

24. Clinical situations indicating obtaining cultures
1. Patients with compromised host defenses which may
require aggressive treatment
2. If the patient received appropriate treatment for 3 days
without improvement
3. Post-operative infection
4. Recurrent infection
5. If actinomycosis is suspected
6. osteomyelitis
25

25. B. DETERMINATION OF ANTIBIOTIC
SENSITIVITY
In the treatment of an infection that has not responded to
initial antibiotic therapy or a post-operative therapy or post-
operative wound infection, the causative agent must be
precisely identified and the antibiotic sensitivity must be
determined.
26

26. B. DETERMINATION OF ANTIBIOTIC
SENSITIVITY
27

27. C. USE SPECIFIC, NARROW-SPECTRUM
ANTIBIOTICS
• Antibiotic with the narrowest spectrum of activity should
be used- fewer organisms have the opportunity to become
resistant
• Minimizes the risk of super-infection
28

28. NARROW-SPECTRUM BROADM SPECTRUM
1. Penicillin G
2. Streptomycin
1. Tetracyclines
2. Chloramphenicol

29. • GRAM-POSITIVE COCCI
• Beta lactams- penicillin,
cephalosporins,
carbapenems
• Vancomycin
• Tetracycline
• Chloramphenicol
• Clindamycin
• Linezolid
• Aminoglycosides
• Fluoroquinolones
• GRAM NEGATIVE COCCI
• Aminoglycosides
• Carbapenems
• Quinolones
• Tetracycline
• Chloramphenicol

30. D. USE OF LEAST TOXIC ANTIBIOTICS
• Selection of least toxic antibiotic from those
effective
• Antibiotics can also damage the human cell
31

31. DRUGS CONTRAINDICATED
• Cephalothin
• Cephaloridine
• Nitrofurantoin
• Nalidixic acid
• Tetracycline
32
RENAL DISEASES LIVER DISEASES
• Erythromycin
• Tetracycline
• Pyrazinamide
• Pefloxacin

32. E. ALLERGY OR INTOLERANCE
• Between 1%-10% of patients who initially take
penicillin, develop an allergic reactions.
• Approximately 10%-15% of penicillin-allergic patients
are also sensitive to cephalosporin (cross-
allergenicity)
• Alternate drug should be used
33

33. F. USE BACERICIDAL RATHER
THAN BACTERIOSTATIC DRUGS
• Bacteriostatic drugs exerts their influence only
when present in the patient’s tissues. Therefore,
bacteria acquire their normal growth after the drug
is completely metabolized.
• Patients, who are pathologically and
therapeutically immunosuppressed, should be
given bactericidal drugs
34

34. F. USE BACERICIDAL RATHER
THAN BACTERIOSTATIC DRUGS
• Advantage of bactericidal drug-
1. less reliance on the host resistance
2. killing of the bacteria by antibiotic itself
3. Faster results
4. Greater flexibility with dosage intervals
35

35. BACTERICIDAL BACTERIOSTATIC
1. Penicillins
2. Cephalosporins
3. Monobactums
4. Aminoglycosides
5. Metronidazole
6. Fluoroquinolones
1. Macrolides
2. Clindamycin
3. Tetracyclines
4. Sulfonamides

36. G. 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
• Newer antibiotics should be used only when they
offer distinct advantages over older ones
• Newer drugs like Methicillin, became available for
penicillinase-producing staphylococci.
37

37. H. COST OF THE ANTIBIOTIC
• Difficult to place a price tag on health
• In some situations, more expensive antibiotic is the drug
of choice
• In other situations, there may be a substantial difference in
price for drug of equal efficacy
• Surgeons/clinicians should consider the cost of the
antibiotic prescribed
38

38. I) PATIENT COMPLIANCE
Drug frequency α 1
patient compliance
OD-compliance…. 80%
BD-compliance……. 69%
QID-compliance………35%
• Clinicians should prescribe antibiotics that can be
given the fewest times daily to improve patient
compliance
39

39. PRINCIPLES OF ANTIBIOTIC
ADMINISTRATION
40

40. PROPER DOSE
• Prescribe or administer sufficient amounts to achieve
the desired therapeutic effect, but not enough to cause
injury to the host.
• MIC (min inhibitory concentration) It is the lowest
concentration of an antibiotic which prevents visible
growth of a bacterium determined in microwell culture
plates.
• Relationship between dose and body weight
Individual dose = BW(kg)/70 x avg adult dose
• Under-dosing – emergence of bacterial resistance.
41

41. Age
The dose of drug for children is often calculated from the
adults dose
Child dose = x adult dose
Child dose = x adult dose
Age
Age +12
Young’s formula
Age
20
Dilling’s formula
42

42. Weight
Clarke’s formula
43
Child’s
dose
Weight of the child x Adult dose
150

43. PROPER TIME-INTERVAL
• The frequency of dose interval is important
• Plasma half life (t 1/2)- is the time with in which one
half of the absorbed dose of drug is excreted.
• The usual dosage interval for the therapeutic use of
antibiotics is four times the t ½.
44

44. PROPER ROUTE OF ADMINISTRATION
• Oral route - most common route, most variable
absorption
• But some of the bacteria are not susceptible to the
drug plasma concentrations produced by oral route
and hence, parenteral routes are chosen.
45

45. CONSISTENCY IN ROUTE OF ADMINISTRATION
• After an initial response has been achieved immediate,
discontinuation of parenteral therapy should not be done,
since this can lead to a fall in therapeutic blood levels,
causing recrudescence of the infection.
• Bacteria are usually eradicated when the antibiotic is given
for 5 to 7 days.
46

46. ANTIBIOTIC DRUG-COMBINATION THERAPY :
Rationale
• Minimize the emergence of antibiotic-resistant
microorganisms.
• To increase the certainty of a successful clinical outcome.
• To treat mixed bacterial infections & severe infections of
unknown etiology.
• To prevent super-infection.
• To decrease toxicity without decreasing efficacy.
47

47. Indications
• In the patients with life threatening sepsis of unknown
etiology.
• When increased bactericidal effect against a specific
organism is desired.
e.g treatment of Enterococcus infection(penicillin &
aminoglycoside)
• Prevention of rapid emergence of resistant bacteria
e.g Tuberculosis
• Treatment of odontogenic infections which could
progress to more serious conditions like
retropharyngeal space infections (penicillin and
metronidazole)
48

48. Rules:
1) 2 bactericidal drugs produce, super-additive effects, but not
antagonism i.e. (1+1>2)
2) The combination of a bacteriostatic and a bactericidal drug
generally results in diminished effects i.e. (1+1<2)
3) 2 bacteriostatic drugs are never inhibitory i.e. (1+1=2)
49

49. Disadvantages :
• Antagonism.
• Increased antibiotic toxicity and allergy.
• Increased likelihood of superinfection
• Discourages specific, etiologic diagnosis
• Encourages inadequate doses, particularly with fixed-dose
combination therapy.
• Increased cost
• Emergence and environmental spread of resistant bacterial strains
50

50. SUPERINFECTIONS AND RECURRENT
INFECTIONS
• Appearance of a new infection as a result of antibiotic
therapy.
• Normal flora acts as a defense mechanism against
infections, but when the indigenous flora is eliminated or
altered by an antibiotic, the pathogenic bacteria resistant
to antibiotics may cause a secondary infection, termed
super infection.
• For example, patients treated for Osteomyelitis or
Actinomycosis, with high doses of antibiotics, are more
susceptible to oral thrush.
51

51. PATIENT MONITORING
• Adjunctive surgery
• Fluid balance
• Nutritional support
Care must be taken specifically on
1. Response to treatment
2. Development of adverse drug reactions
52

52. RESPONSE TO TREATMENT
• Most commonly, the response begins by the 2nd day
and initially produces a subjective sense of feeling
better.
• There after, objective signs of improvement occur
including a decrease in temperature, swelling, pain and
lessening of trismus.
• Duration of Therapy- 5/7 days or extended
53

53. CAUSES OF FAILURE OF TREATMENT
1. Inadequate surgical treatment
2. Depressed host defense
3. Presence of foreign body
4. Non-compliance
5. Antibiotic problems:
a) Drug not reaching infection – limited vascularity
b) Dose not adequate
c) Wrong bacterial diagnosis
d) Wrong antibiotic
e) Antibiotic resistance
54

54. ADVERSE REACTIONS
• These reactions may include accelerated anaphylactic
reactions (type 1) or less severe reactions associated with
edema, urticaria, and itching.
• The less sever reactions that develops as a rash or urticaria
may begin immediately or many hours after exposure (type
2 & 3)
55

55. Delayed hypersensitivity reactions (type 4)
( most common sign is a persistent low-grade fever
even after pain, swelling and other problems subside.
Temperature elevation resolves in 24 to 48 hrs, after
the drug is withdrawn.)
Antibiotics frequently causes gastrointestinal
distress.
56

56. ANTIBIOTIC-ASSOCIATED COLITIS
It is one of the toxic reactions associated with antibiotics.
Clindamycin
Ampicillin /amoxicillin
Cephalosporins
Treatment :
• discontinuation of antibiotic
• restoration of fluid and electrolyte balance
• administration of ant-clostridia antibiotics
• (oral vancomycin, metronidizole)
57

57. PRINCIPLES OF MANAGEMENT
1. Determine severity of infection
2. Evaluate host defenses –disease status/
medication
3. Establish Drainage
4. Prescribing proper dosage & regimen
5. Review & Follow-up
6. Culture & sensitivity testing
58

58. Culturing is considered in:
1. Initial antibiotic failure
2. Infection spreading to other spaces
3. Patient demonstrates signs & symptoms of
septicemia
59

59. ANTIBIOTIC
PROPHYLAXIS
”Antibiotic prophylaxis has been defined as
the preoperative use of antibiotics to
prevent infections”.
Danial Laskin

60. PRINCIPLES OF ANTIBIOTIC
PROPHYLAXIS
1. Increased risk of significant bacterial
contamination and a high incidence of infection
2. Organism must be known
3. Antibiotic susceptibility must be known to be
effective
4. To minimize adverse effects the antibiotic should
be in circulation at time of surgery
5. Must be continued for not more than 4 hrs after the
surgery
6. Four times the MIC of the causative organism
7. Shortest effective antibiotic exposure
61

61. INDICATIONS FOR ANTIBIOTIC
PROPHYLAXIS
1. Compromised host defenses
a) Physiological- old age, obesity, malnutrition
b) Disturbances in circulation- massive
transfusion, recent surgery
c) Disease related- poorly controlled diabetes,
cancer, leukemia, cirrhosis, renal diseases
d) Compromised immunity- multiple myeloma,
total body irradiation, splenectomy
e) Immunosuppressants- cytotoxic drugs,
steroids, cyclosporin
62

62. INDICATIONS FOR ANTIBIOTIC
PROPHYLAXIS
2. Potential for bacterial contamination
3. Procedures with high infection rate
4. Surgical procedures in which there is high
mortality/morbidity rate following infection
5. When foreign body is inserted into the tissue
63

63. Classification based on the Risk of Infection:
(Altemeier et al)
A. Clean surgical wounds:
a) Low infection rate
b) No significant tissue trauma
c) Incision is closed primarily
d) The wound is not drained
e) No communication with the oral cavity
64

64. B. Clean-contaminated wound:
Similar to clean wound except there is communication
with the oral cavity.
C. Contaminated wound:
Fresh traumatic injuries that involve the oral cavity
D. Dirty wounds:
Traumatic injuries with delayed treatment that
communicate with oral cavity and contain devitalized
tissues or foreign bodies.
65

65. NEED FOR POST-OPERATIVE
ANTIBIOTICS
1. Compromised immunity
2. Inflammation at the surgical site
3. Evidence of wound dehiscence
4. Active periodontal disease
5. Poor oral hygiene
6. Prolonged surgery
7. Wound contamination during surgery
66

66. PROPHYLACTIC USES
OF ANTIBIOTICS IN
MAXILLOFACIAL
SURGERY
67

67. ANTIBIOTIC PROPHYLAXIS IN
SURGICAL REMOVAL OF WISDOM
TEETH
1. Factors influencing the rate of postoperative
infection may need to consider postoperative
antibiotics
• History of pericoronitis
• Smoking
• Old age
• Poor oral hygiene
• Duration of surgery
• Amount of bone removal
• Presence of foreign bodies—hemostats or
devitalized bone fragments
• Operator skill
68

68. ANTIBIOTIC PROPHYLAXIS IN
SURGICAL REMOVAL OF WISDOM
TEETH
2. Amoxicillin & Amoxicillin—clavulanic acid equally
effective
3. Systemic administration more effective
4. Single preoperative dose: 30–90 min prior to
procedure
5. Usually double the usual strength is given
preoperatively
6. Antibiotics reduce incidence of alveolar osteitis
69

69. ANTIBIOTIC PROPHYLAXIS IN
SURGICAL REMOVAL OF WISDOM
TEETH
7. Topical tetracycline, chlorhexidine, & metronidazole
effective in reducing the infection rate
8. Preoperative and extended postoperative doses may
be required in immunocompromised patients
9. No antibiotic prophylaxis required in removal of
asymptomatic mandibular third molars and maxillary
third molars in healthy individuals
70

70. ANTIBIOTIC PROPHYLAXIS IN THE
PLACEMENT OF DENTAL IMPLANTS
Care to be taken :
• Through oral prophylaxis & measures to improve oral hygiene
• Stabilize oral focus of infection
• Procedure in a well-monitored aseptic environment- disinfection, draping, hand
scrubbing, sterile gowns & gloves, sterile instruments
• Prevent contamination of implants with contact with skin, infected oral mucosa, &
sinus lining
71

71. ANTIBIOTIC PROPHYLAXIS IN THE
PLACEMENT OF DENTAL IMPLANTS
• Bactericidal antibiotic with coverage against pathogenic oral microflora
• Preoperative administration of antibiotics—1 h before the procedure, twice the
therapeutic dose —Amoxicillin 2gm, / clindamycin 600 mg 1 h prior to
surgery
• Chlorhexidine gluconate rinses—hugely effective in controlling the immediate
local infection
72

72. ANTIBIOTIC PROPHYLAXIS IN THE
PLACEMENT OF DENTAL IMPLANTS
Only Chlorhexidine 0.12% rinse twice daily in healthy individuals
(a) Simple implant,
(b) Short duration,
(c) No bone graft,
(d) Sterile environment is ensured.
Single preoperative dose + Chlorhexidine 0.12% rinse twice daily in healthy
individuals
(a) Multiple implants with minimal tissue reflection,
(b) Immediate extraction & implant placement,
(c) Socket bone grafting.
73

73. ANTIBIOTIC PROPHYLAXIS IN THE
PLACEMENT OF DENTAL IMPLANTS
Single preoperative dose + 3 doses / day X 3 postoperative days + Chlorhexidine
0.12% rinse twice daily in healthy individuals
(a) Multiple implants with extensive tissue reflection,
(b) Multiple extractions & implant placement,
(c) Bone grafting—allografts,
(d) Long duration.
74

74. ANTIBIOTIC PROPHYLAXIS IN THE
PLACEMENT OF DENTAL IMPLANTS
Single preoperative dose + 3 doses / day X 5 postoperative days + Chlorhexidine 0.12%
rinse twice daily
(a) In medically compromised patients,
(b) Extensive tissue reflection,
(c) Full arch implants,
(d) Block bone grafting—autografts,
(e) Indirect sinus floor lift procedures,
(f) Active periodontal disease.
Loading dose on the previous day + 3 doses / day X 5 postoperative days +
Chlorhexidine 0.12% rinse twice daily -In sinus lift procedure
75

75. ANTIBIOTIC PROPHYLAXIS IN
ORTHOGNATHIC SURGERY
Risk factors for Surgical site infection-
(a) Longer surgery;
(b) Short-term antibiotic prophylaxis;
(c) Extraction of a third molar during surgery;
(d) Greater number of osteotomies performed;
(e) Older age;
(f) Smoking;
(g) Poor oral hygiene;
(h) Compromised immune system.
76

76. ANTIBIOTIC PROPHYLAXIS IN
ORTHOGNATHIC SURGERY
• Orthognathic surgery - clean–contaminated wound—with the
osteotomized maxilla / mandible exposed to oral / nasal / antral
cavities—Antibiotics needed
• Need for antibiotics in presence of bone plates & screws
• Loading dose of double strength 1 h prior to incision
• Commonly isolated organisms—aerobic bacteria—streptococci (43%)
& anaerobic bacteroides (50%)
77

77. ANTIBIOTIC PROPHYLAXIS IN
ORTHOGNATHIC SURGERY
• Amoxicillin / amoxicillin—clavulanic acid—best suited
• Higher infection rate—mandibular osteotomies with transbuccal approach for
fixation
• Longer procedures & segmental osteotomies—more prone for infection
• Concomitant removal of mandibular third molars does not increase the risk
for postoperative infection, though may cause issues with fixation.
78

78. ANTIBIOTIC PROPHYLAXIS IN
MAXILLOFACIAL TRAUMA
• Risk factors for Surgical site infection-
(a) Longer surgery;
(b) Older age;
(c) Smoking;
(d) Poor oral hygiene;
(e) Compromised immune system.
• Mandibular fractures/ fractures of the teeth-bearing area—open /
compound fractures.—Antibiotics needed
79

79. ANTIBIOTIC PROPHYLAXIS IN
MAXILLOFACIAL TRAUMA
• Need for antibiotics in presence of bone plates & screws
• Loading dose of double strength 1 h prior to incision
• Beta-lactam antibiotics—preferred
• Higher infection rate—in fractures involving mandibular teeth–
bearing areas
• Longer duration of antibiotics in immunocompromised patients
80

80. ANTIBIOTIC PROPHYLAXIS IN
MAXILLOFACIAL TRAUMA
• Chances of infection more with open reduction than in those
treated with closed reduction with no antibiotic prophylaxis
• But with single dose of perioperative antibiotics, no significant
difference between closed & open reduction
• Delayed healing and increased infection rate with tobacco
smoking
81

81. WOUND TYPE INTRAOPERATIVE IV POSTOPERATIVE
TOPICAL
POSTOPERATIVE IV
Abrasion Bacitracin Zinc Bd
Neomycin Sulfate Bd
Contusion And
Hematomas
Cephalosporin
Punctures Cephalosporin
Simple Laceration Bacitracin Zinc Bd
Neomycin Sulfate Bd
Cephalosporin
Complex Laceration Cephalosporin Bacitracin Zinc Bd
Neomycin Sulfate Bd
Cephalosporin
Soft Tissue Avulsion Cephalosporin Bacitracin Zinc Bd
Neomycin Sulfate Bd
Cephalosporin
Maxillary &
Mandibular Fracture
Cephalosporin Bacitracin Zinc Bd
Neomycin Sulfate Bd
Cephalosporin
82

82. DIABETES MELLITUS AND
ANTIBIOTIC PROPHYLAXIS
• Antibiotic prophylaxis is warranted only in conditions where a normal patient also
would benefit from it.
• Poorly controlled diabetic patients would require normalization of their
hyperglycemic state prior to elective procedures.
• In emergency situations, antibiotic prophylaxis prior to the surgical incision is
desirable and attempts should be made to control the glycemic level during the peri-
and postoperative period

83. 84
ANTIBIOTIC PROPHYLAXIS IN
HEAD AND NECK ONCOLOGY
• Increased risk of Surgical site infection-
• Multiple procedures done at a single operation,
• Large wound area,
• Long procedure,
• Tobacco & alcohol abuse
• Immunocompromised patients
• Probable pathogens- Escherichia &
staphylococcal spp
• Preferred antibiotic- ampicillin & sulbactum
• Bartella et al. (2017) - Statistically significant
reduction in infectious complications with

84. ANTIBIOTIC PROPHYLAXIS IN
CLEFT SURGERIES
• In recent studies, statistically significant
reduction in incidence of palatal fistulas with 5
days of post-operative antibiotics
• Also, one dose of antibiotic before the incision
has been advocated by other authors and may
be more effective in preventing complications
related to wound infection
85

85. High-risk cardiac conditions, which require antibiotic prophylaxis
• Prosthetic cardiac valves
• Congenital heart diseases—unrepaired, with palliative shunts or
conduits or repaired with prosthetic material or those repaired, but
with residual defects
• Previous IE
• Cardiac transplants who have developed valvulopathy
86

86. Endocarditis prophylaxis
recommended
87

87. REGIMEN FOR ENDOCARDITIS PROPHYLAXIS
Situation Agent Adults Children
Oral Amoxicillin 2g 50mg/kg
Unable to take oral
medication
Ampicillin
or
Cefazolin/ Ceftriaxone
2g IM/IV
1g IM/IV
50mg/kg IM/IV
50mg/kg IM/IV
Allergic to Penicillin/
Ampicillin - oral
Cephalexin
or
Clindamycin
or
Azithromycin /
Clarithromycin
2g
600mg
500mg
50mg/kg
20mg/kg
15mg/kg
Allergic to
Penicillin/Ampicillin -
unable to take oral
medication
Cefazolin/ Ceftriaxone
or
Clindamycin
1g IM/IV
600mg IM/IV
50mg/kg IM/IV
20mg/kg IM/IV
Regimen –single dose, 30 to 60 min before procedure
88

88. ANTIBIOTICS IN PREGNANCY
• Penicillin’s, Cephalosporins, Erythromycin, And Clindamycin
cross the placenta have therapeutic effects on the fetus as well
as the mother and are not associated with congenital defects
• Aminoglycosides may produce fetal toxicity and
nephrotoxicity.
• Tetracycline if given after 5 months of gestation may result in
permanent discoloration of fetal teeth, maternal liver toxicity,
and congenital defects
• Sulfonamides when administered in 3rd trimester /close to
delivery persists in blood for 2 to 3 days after birth and are
associated with jaundice, hemolytic anemia, and kernicterus
in new born.
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89. ANTIBIOTIC RESISTANCE
• Unresponsiveness of a micro-organism
• Resistance to an antimicrobial can arise-
• Mutation in the gene that determines
sensitivity/resistance to the agent
• Acquisition of extra-chromosomal DNA
(plasmid) carrying a resistance gene
• Bacteriophages
• Mosaic genes
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90. 91

91. 92

92. CONCLUSION
• Although antibiotics do not prevent all post-operative
infections, they can reduce their incidence significantly
when administered correctly.
• As surgeons, we should prescribe effective, short-course
therapies, directed at improving the outcome of our patients.
• Future treatment strategies will not only include the
aggressive use of traditional management methods but also
the understanding of normal immune system-associated
defects and newer antimicrobials.
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93. REFERENCES
1. Oral & Maxillofacial infections - Topazian
2. Oral & Maxillofacial Clinics of North America
3. Medical problems in Dentistry – Cawson & Scully.
4. Antibiotic & Chemotherapy – Francis O Grady
Harold P. Lambert
5. Medical pharmacology, by K.D. Tripathi, 5th edition
6. Oral and Maxillofacial Surgery for the clinician
7. www.who.int/drug resistance
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