Antibiotic Use in Dental Infection VGH-TPE

INTRODUCTION ■ Diagnosis and Treatment of infection ■ Assessment of the Patient ■ Diagnosis and Treatment of infection ■ Antibiotic Therapy ■ Indications for Prophylaxis ■ Antifungal Agent VGH-TPE

DIAGNOSIS: Infection Determine etiology > odontogenic > trauma wound, animal bite > TB, fungi, actinomycoses VGH-TPE

MICROBIOLOGY Most oral infections are mixed in origin consisting of aerobic and anaerobic gram positive and gram negative organisms VGH-TPE

COMMONLY USED A/B Mechanism of the antibiotics VGH-TPE

First choice for odontogenic infection COMMONLY USED A/B 1. Groups of Penicillin First choice for odontogenic infection G(+) cocci and rod, spirochetes, anaerobes 0.7~10% hypersensitivity => PST Nature: penicillin G (IV), penicillin V (PO) Penicillinase-resistant: oxacillin, dicloxacillin Extended spectrum: ampicillin, amoxicillin Combine β-lactamase inhibitor: augmentin VGH-TPE

More resistance to penicillinase G(+) cocci, many G(-) rods 2. Cephalosporin More resistance to penicillinase G(+) cocci, many G(-) rods Third generation: Pseudomonas aeruginosa Second choice (less effect for anaerobes) First generation Second generation Third generation Forth generation Cefazolin Keflor Claforan Cefepime Generation by G(-) rods against VGH-TPE

Bacteriostatic -> bactericidal 3. Clindamycin G(+) cocci Bacteriostatic -> bactericidal Second-line drug: should be held in reserve to treat those infections caused by anaerobes resistant to other antibiotics Not be used as a subsitute for penicillin or other drugs that are effective against orofacial infections VGH-TPE

G(-) aerobes, some G(+) aerobes eg S. aureus 4. Aminoglycoside G(-) aerobes, some G(+) aerobes eg S. aureus Poorly absorbed from GI tract Adjustment of dosage in renal dysfunction Drugs: Gentamicin, Amikacin, Amikin Combined with penicillin or cephalosporin No activity against anaerobes, so don’t use alone VGH-TPE

Only for obligate anaerobes Can cross blood-brain barrier 5. Metronidazole* Only for obligate anaerobes Can cross blood-brain barrier To treat serious infections caused by anaerobic bacteria, combined with β-lactam A/B Effective against Bacteroides species, esp. in periodontal infections Drugs: Anegyn, Flagyne Avoid pregnant women VGH-TPE

G(+), most anaerobes, some G(-) cocci (Neisseria) Given intravenously, 6. Vancomycin G(+), most anaerobes, some G(-) cocci (Neisseria) Given intravenously, Adjustment of dosage in renal dysfunction 主要用於治療MRSA，口服是用來治療pseudomembrane colitis。注意IV給葯速度 VGH-TPE

Wide spectrum, highly active against anaerobes 7. Chloramphenicol Wide spectrum, highly active against anaerobes Limited to severe odontogenic infection threatening to the eye or brain Severe toxicity VGH-TPE

G(+) cocci, oral anaerobes Bacteriostatic 8. Erythromycin G(+) cocci, oral anaerobes Bacteriostatic Second choice for odontogenic infections Indication for out-patients with mild infection Drug resistence: 50% of S. aureus, Strep. viridans, For PST(+) patient VGH-TPE

Only against anaerobes 9. Tetracycline* Only against anaerobes Contraindications: pregnant women, children <12 Limited usefulness in orofacial infection Use as adjunctive therapy for refractory periodontitis Most likely to cause superinfection VGH-TPE

Use the narrowest spectrum antibiotics SELECTION of A/B Use the narrowest spectrum antibiotics Use the antibiotics with the lowest toxicity and side effects Use bactericidal antibiotics if possible Be aware of the cost of antibiotics VGH-TPE

Side Effect of Commonly Used Antibiotics 1. Penicillin hypersensitivity 2. Cephalosporin 3. Clindamycin diarrhea, pseudomembrane colitis 4. Aminoglycoside damage to kidney, neurotoxicity 5. Metronidazole* GI disturbance, seizures 6. Vancomycin neurotoxicity, thrombophlebitis 7. Chloramphenicol bone marrow suppression 8. Erythromycin mild GI disturbance 9. Tetracyclin* tooth discoloration * Not use in pregnancy. Vancomycin IV too rapid-> decrease blood pressure. BP monitor is needed. VGH-TPE

ANTIFUNGAL AGENT Most of fungal infection are from candida Commonly used drugs: (1) Nystatin (Mycostatin)= PO 4-600,000 U qid (2) Amphotericin B= IV for severe systemic infec. (3) Fluconazole, Ketoconazole VGH-TPE