Antibiotics - dental pharmacology

1. ANTIMICROBIAL USED FOR
DENTAL INFECTIONS
Dental Clinical Pharmacology
By
Taha Hussein Kadi , MSc
Lecturer of Pharmacology & Toxicology
UST

2. Definitions
• Antibiotics are chemical substances obtained
from microorganisms that kill or suppress growth
of bacteria.
• Bactericidal agents They kill or destroy bacteria,
e.g. penicillins, cephalosporins, etc.
• Bacteriostatic agents They inhibit the growth and
multiplication of bacteria, e.g. tetracyclines,
erythromycin, etc.
– At high concentration, some of the ‘static’ drugs may
produce ‘cidal’ effect

12. • Cost
– Cost is an important
factor in choosing an
antibiotic for a patient.
– If the perfect antibiotic is
chosen and prescribed
but the patient does not
purchase the medication
because it is too
expensive.

13. RATIONAL USE OF ANTIINFECTIVE
AGENTS IN DENTISTRY
Stages of Infection
• Stage 1
– Acute abscess and cellulitis are primarily the result of
gram-positive organisms.
– The drug of choice in patients without a penicillin
allergy is penicillin or amoxicillin.
– The patient must complete the full course of therapy
in order to ensure that all of the bacteria are killed off
and to help reduce to the chance for resistance.
– For those with an allergy to penicillin, erythromycin
or clindamycin may be used.

14. • Stage 2
– the infection is mixed. the gram-positive bacteria
or the anaerobes.
– The gram-positive organisms can be managed
with the same drugs as in stage 1.
– To attack the anaerobes, an antibiotic with good
anaerobic coverage is needed.
– The two antibiotics with the most anaerobic
coverage are clindamycin and metronidazole.
– Penicillin V also has anaerobic coverage.

15. • Stage 3
– In stage 3, the organisms have coalesced into one
area and are almost solely anaerobic. Most often
incision and drainage are sufficient.
– If chronic infection persists or if the patient is
immunocompromised, use of an antibiotic with
anaerobic coverage is warranted.

16. Failure of Antibiotics Therapy
• Patient adherence
• Ineffective antibiotic
• Resistant organism
• Inadequate host defenses

17. DOSES
Rx: Penicillin V potassium 500 mg
Sig: Take 1 tablet 4 times/day for 7 to 10 days
(consider a loading dose of 1 g for acute
infection)
Rx: Clindamycin 150 or 300mg
Sig: Take 1 capsule 4 times/day for 7 to 10 days

18. DOSES
Rx: MetroNIDAZOLE 250 or 500 mg
Sig: Take 1 tablet 3 times/day for 8 days
Rx: Augmentin 375or625mg
Sig: Take 1 tablet 3 times/day for 7 to 10 days
Rx: Augmentin 875 or 1000 mg
Sig: Take 1 tablet twice daily for 7 to 10 days

19. DOSES
Rx: Erythromycin 250 mg
Sig: Take 1 tablet 4 times/day for 7 to 10 days
Rx: Azithromycin 500 mg tablets
Sig: Take 1 tablet daily for 4 to 7 days as directed

20. Antifungals
• Candida Albicans
• Antifungals are used to treat oral or
oropharyngeal fungal infections but
underlying factors should first be considered.
• In immunocompromised patients, antifungals
are used for prophylaxis, administrated
systemically (azoles)

21. Antifungals Agents
• Nystatin is not active orally, very active ative
topically.
• Dose qid – 500 000 unit lozenge,
– 100 000 unit per mL of suspension
• Amphotericin is close to Nystatin
characteristics
• Topically applied 10 to100 mg q6h

22. • Miconazole is active topically and orally.
• Also has antibacterial activity.
• Dose – 250 mg tablet q6h – 25 mg/ml gel
(Daktarin®) used as 5 mL q6h for 14 days

23. ANTIVIRAL
• Herpes viruses are associated with most oral
viral infections
• Also (papillomaviruses, and enteroviruses).
• HIV and other viruses may also cause
orofacial lesions.

24. ANTIVIRAL
• Management of viral infections is supportive,
as, at present, there are few antiviral agents of
proven efficacy.
• Most antivirals will achieve maximum benefit
if given early in the disease.

25. ANTIVIRAL
• Systemic Aciclovir should be used with caution in
pregnancy and renal disease.
– may cause rashes and CNS effects(vertigo, dizziness,
fatigue, insomnia, irritability, and mental depression).
• Famciclovir should also be used with caution in
pregnancy and renal disease.
– may cause headache and nausea.
• Topical Forms are preferred– 5 application by day

26. CLINICAL CASE STUDY
• A 25-year-old female patient presents with
localized periodontitis with a 6mm pocket
along the mesial root of tooth #14. A decision
is made for treatment with gingival flap
surgery. The patient's medical history is
remarkable for prosthetic mitral valve
placement and for penicillin-induced
angioedema?

27. CLINICAL CASE STUDY
A 35-year-old obese female patient presents in the
office with a canine fossa abscess associated with
the root remnant of tooth #6. Incision and drainage
of the abscess, extraction of the root remnant, and
antibiotics are scheduled.
• What are antibiotics you will prescribe?
• This patient is complicated with
Pseudomembranous coilitis (Superinfection)?
What antibiotics are most commonly associated
with this?
• How to treat this problem?

28. CLINICAL CASE STUDY
Haley Rothstein is a 8-year-old girl who has been
coming to your practice for the past 3 years. Her
mother calls you today because she has noticed
that Haley has a “sort of white milky discharge
coming from her mouth.” Haley had a bacterial
infection last week and was treated with
amoxicillin.
1. What is happening to Haley?
2. What is the “white milky discharge” and how
should it be treated?