Amoxicillin in dentistry

1. Management of dental
infections

2. Overview
• Common bacterial infections in dentistry
• Microbiology of infections
• Empiric Therapy Regimens
• Amoxicillin-clavulanate
• Related studies

3. Common types of bacterial infection in
dentistry:
• Pulpitis
• Periapical periodontitis
• Periodontitis
• Pericoronitis
http://www.dentalcare.com/enUS/dentaleducation/continuingeducation/ce336/ce336.aspx?ModuleName=coursecontent&PartID=4&SectionID=-1

4. Contd..
• Dental caries
• Postsurgical
infections
• Gingivitis

5. Microbiology
Odontogenic infections are multimicrobial:
• Gram (+) cocci, aerobic and anaerobic:
– Streptococci and their anaerobic counterpart, peptostreptococci
– Staphylococci, and their anaerobic counterpart, peptococci
http://www.dentalcare.com/en-US/dental-education/continuing-education/ce336/ce336.aspx?ModuleName=coursecontent&PartID=4&SectionID=-1

6. • Gram (+) rods:
– Lactobacillus, diphtheroids,
• Gram (-) rods:
– Fusobacterium, Bacteroides, Eikenella, Psuedomonas
(occasional)

7. Pathophysiology
• Dental caries results when the demineralization which occurs when
certain species of micobes start producing acid and can survive in it.
• Dental caries erode the protective layers of the tooth (ie, enamel,
dentin) and allow bacteria to invade the pulp, producing a pulpitis.
http://emedicine.medscape.com/article/909373-overview#a5

8. Pathophysiology
• Pulpitis can progress to necrosis, with bacterial invasion of the
alveolar bone, causing an abscess.
• A periapical abscess that originates in the dental pulp and is
usually secondary to dental caries is the most common dental
abscess in children.
http://emedicine.medscape.com/article/909373-overview#a5

9. Pathophysiology
• A periodontal abscess involves the supporting structures of the teeth
(periodontal ligaments, alveolar bone).
• This is the most common dental abscess in adults, but may occur in
children with impaction of a foreign body in the gingiva.
• Pericoronitis describes the infection of the gum flap (operculum) that
overlies a partially erupted or impacted third molar.
http://emedicine.medscape.com/article/909373-overview#a5

10. Empiric Therapy options
First line of drugs
• Penicillin V / Penicillin G
• Amoxicillin-clavulanate
• Clindamycin
http://emedicine.medscape.com/article/2060395-overview#showall
Second Line drugs
• Metronidazole
• Moxifloxacin
• Erythromycin
• Cephalexin

11. Amoxicillin-clavulanate
• Amino penicillins
• First line of drug in the management of dental infections especially
in treating penicillinase-producing staphylococci or those involving
gram-negative bacteria.
• Amoxicillin acts by inhibiting the bacterial cell wall synthesis and
clavulanic acid acts by inhibiting the penicillinase enzyme which
deactivates amoxicillin – synergistic action
http://www.webmd.com/drugs/2/drug-1531/amoxicillin-oral

12. Spectrum of activity
Gram-Positive Bacteria
Staphylococcus aureus
Enterococcus faecalis
Staphylococcus epidermidis
Staphylococcus saprophyticus
Streptococcus pneumoniae
Streptococcus pyogenes
Viridans group Streptococcus
http://www.rxlist.com/augmentin-drug/clinical-pharmacology.htm

13. Spectrum of activity
Gram-Negative Bacteria
Eikenellacorrodens
Proteus mirabilis
Enterobacter species
Escherichia coli
Haemophilus influenzae
Klebsiella species
Moraxella catarrhalis
http://www.rxlist.com/augmentin-drug/clinical-pharmacology.htm

14. Spectrum of activity
Anaerobic Bacteria
Bacteroidesspecies including Bacteroides fragilis
Fusobacterium species
Peptostreptococcus species
http://www.rxlist.com/augmentin-drug/clinical-pharmacology.htm

15. Dosage
• Forms: Suspension, chewable tablet, tablet, capsule
• Usual oral dosage:
 Children: >3 months and <40kg: 20-40mg/kg/day in divided doses
8th hourly
OR 25-45 mg/kg/day in divided doses every 12 hours

16. Dosage
 Children: >40 kg and adults: 250-500 mg every 8 hours
OR 500-875 mg every 12 hours
 Adults : > 40 kg: 250-500 mg q8h or 875 mg q12h for at least 7
days; maximum dose: 2g/day

17. Benefits over other 1st line drugs
• Available in various dosage formulations
• Covers both Gram positive and Gram negative bacteria including
anaerobic bacteria
• Broad spectrum of activity
• Well tolerated
• Good compliance
• Safer with fewer adverse effects

18. Related studies
• A comparative study on amoxicillin and clindamycin was carried as
a rationale for antibiotic prophylaxis against infective endocarditis
involving 160 patients.
They reported that oral amoxicillin given prior to dental extraction
produced a significant reduction in post-extraction bacteraemia.
Maharaj B, Coovadia Y, Vayej AC. A comparative study of amoxicillin, clindamycin and chlorhexidine in the prevention of post-extraction bacteraemia.Cardiovascular

19. Related studies
• In a randomized, double blind study involving 123 participants it was
observed that , amoxicillin administered pre- or postoperatively
demonstrated greater efficacy than placebo in preventing
postoperative complications in patients undergoing third molar
surgery.
http://www.sciencedirect.com/science/article/pii/S0278239111000954

20. Related studies
• Another study evaluated amoxicillin concentration in the serum,
jaw cyst and jaw bone after single oral administration among
44patients who underwent enucleation of jaw cyst
Reported that amoxicillin attains higher levels in periodontal cysts
than in dentigerous cysts, and higher in maxillary bone than in
mandibular bone.
Akimoto Y, Kaneko K, Tamura T. Amoxicillin concentrations in serum, jaw cyst, and jawbone following a single oral administration. J Oral Maxillofac Surg. 1982 May;40(5):287-

21. Comparative Efficacies of Amoxicillin, Clindamycin, and Moxifloxacin in
Prevention of Bacteremia following Dental Extractions (BDE)
Prevalence of bacteremia at
the baseline and
postextraction (30 s, 15
min, and 1 h after
completion of the dental
extractions) in the different
study groups.
Conclusion: AMX continues to be the antibiotic of choice for the prevention of BDE in patients
who are “at risk” of BE and who are not allergic to PEN. MXF is a safe prophylactic alternative
when beta-lactams are contraindicated.
http://aac.asm.org/content/50/9/2996.full

22. Related studies
• In a randomised comparative study, of co-amoxiclav and penicillin V for
dentoalveolar infections
• After drainage all patients improved but co-amoxiclav treatment provided
significantly greater decrease in toothache during the second and third days
post drainage.
• This may explained by the eradication of the beta-lactamase producing
bacteria with co-amoxiclav that would not be eradicated by penicillin V.
Lewis MA, Carmichael F, MacFarlane TW, Milligan SG. A randomised trial of co-amoxiclav versus penicillin V in the treatment of acute dentoalveolar abscess.

23. Related studies
• A comparitive study of amoxicillin and penicillin on Bacteraemia after
dental extraction demonstrated that
• Both penicillin V (2 g oral dose) and amoxycillin are effective in
reducing the incidence of bacteraemia following dental extraction.
• However, amoxycillin is preferable to penicillin V for the oral
prophylaxis of endocarditis as it can provide much higher serum
levels than penicillin V during the 6 to 8 hours following extraction.
Shanson DC, Cannon P, Wilks M. Amoxycillin compared with penicillin V for the prophylaxis of dental bacteraemia. J Antimicrob Chemother. 1978

24. Thank you