Anti-infective Therapy

1. Anti-infective Therapy Dr Manal Ahmad Abu Al Ghanam

2. Definitions • Chemotherapeutic agent: acts to reduce the number of bacteria present. • Antibiotic: naturally occuring semisynthetic or synthetic type of anti-infective agent. • Antiseptic: a chemical antimicrobial agent applied topically or subgingivally.

3. Route of administration • Systemic:may be a necessary adjunct in controlling bacterial infection. • Local: directly into the pocket has a potential to provide greater concentrations. • A single agent can have a dual mechanism of action (tetracyclines)

4. Systemic administration of antibiotics • Treatment of periodontal disease is based on infectious nature of the disease. • An ideal antibiotic for use in prevention and treatment of periodontal disease: • Specific for perio. pathogens. • Allogenic. • Nontoxic. • Substantive. • Inexpensive.

5. Systemic administration of antibiotics • The treatment of the individual patient is based on: • Patient’s clinical status. • Nature of colonizing bacteria. • Ability of the agent to reach the site of infection. • Risks and benefits associated with the proposed treatment.

6. Systemic administration of antibiotics • The clinician is responsible for choosing the correct antimicrobial agent. • Some adverse reactions include: • Allergic/anaphylactic reactions. • Superinfections of opportunistic bacteria. • Development of resistant bacteria. • Interaction with other medications. • Upset stomach. • Nausea. • Vomiting.

7. Tetracyclines: • Used widely in perio.disease treatment. • Used frequently in treatment of refractory periodontitis and LAP. • Has the ability to concentrate in the periodontal tissue and inhibit the growth of Aggregatibacter actinomycetemcomitans. • Exert ananticollagenaseeffect that can inhibit bone destruction and may aid bone regeneration.

8. Tetracyclines: • Bacteriostatic….effective against rapidly multiplying bacteria. • G+ve>>G-ve bacteria. • Concentration in gingival crevice 2-10 times in serum. • Long term regimens can develop resistant bacteria.

9. Tetracycline HCL • Administration 250mg 4 times daily (qid). • Inexpensive • Side effects: GI disturbances, photosensitivity, increased blood urea nitrogen, tooth discoloration when administered to children up to 12 years.

10. Minocycline • Suppresses spirochetes and motile rods. • Given twice daily (bid) facilitating compliance. • Less photosensitivity and renal toxicity. • Side effects: are similar to those of tetracycline however there is increased incidence in vertigo. • Only tetracycline that can discolor permanently erupted teeth and gingival tissue when administered orally.

11. Doxycycline • Has same spectrum as minocycline,but only given once daily(qd) more compliant!! • Most Photosensitizing Agent In Tetracyclines. • DOSES: • Antiinfective agent; 100mg qd or 50mg bid . • Sub antimicrobial (inhibit collagenase) 20 mg twice daily. • Periostat!!

12. Metronidazole • Nitroimidazole compound developed for protozoal infection. • Bactericidal to anaerobic organisms because it disrupts the bacterial DNA. • Effective against P.g and P.i but not the drug of choice against A.a unless combined to other antibiotics!!!!

13. Metronidazole • Used to treat: • Gingivitis. • Necrotizing ulcerative gingivitis. • Chronic periodontitis. • Aggressive periodontitis. • Doses: • 250mg 3 times daily(tid) for a week. • Arestien.(local delivery sustained release form).

14. Metronidazole • Side effects: • Antabuse effect when alcohal is ingested. • Inhibits warfarin metabolism. • Patient on anticoagulant should avoid prothrombin time. • Should be avoided in patients on lithium. • Metallic taste in mouth.

15. Penicillins • Most widely used antibiotic. • Inhibit bacterial cell wall production and so they are bactericidal. • Induce allergic reactions and bacterial resistance. • Amoxicillin and amoxicillin-clavulanate potassium (Augmentin).

16. Penicillins • Amoxicillin is semisynthetic penicillin with extended antiinfective spectrum (G+ve,G-ve) • Amoxicillin is for treatment of aggressive periodontitis both localized and generalized forms. • Augmentin is used for management of LAP or refractory periodontitis.

17. Cephalosporins • Are not used for treatment of dental disease. • Patients allergic to penicillin are allergic to cephalosporins.

18. Clindamycin • Effective against anaerobic bacteria with strong affinity for osseous tissue. • For penicillin allergic patients. • Efficacy to periodontitis refractory to tetracycline therapy. • DOSES:150mg(qid) for 10 days. 300mg(bid) for 8 days. • Associated with pseudomembranous colitis.

19. Ciprofloxacin • A quinolone active against gram negative rods (all facultative, some anaerobic putative periodontal pathogens). • Ciprofloxacin therapy may facilitate establishment of a microflora associated with periodontal health. • ONLY antibiotic that all strains of A.a are susceptible.

20. Ciprofloxacin • Side effects: metallic taste, inhibit the metabolism of theophilline and caffeine, enhance the effect of warfarin and other anticoagulants.

21. Macrolids • Inhibit protien synthesis,bacteriostatic or bactericidal depending on drug concentration. • Macrolids used in periodontal treatment include erythromycin,spiramycin,and azithromycin. • DOSES: Therapeutic doses of 250mg/day for 5 days after an initial loading dose of 500mg.

22. Macrolids • DID YOU KNOW…. • Erythromycin is not concentrated in GCF, spiramycin is excreted in high concentration in saliva and it has been proposed that azithromycin penetrates fibroblasts and phagocytes in concentrations 100-200 times greater than extacellular compartment!!!

23. SERIAL AND COMBINATION ANTIBIOTIC THERAPY • Periodontitis is a mixed infection, in this condition treatment requires more than one antibiotic serially or in combination!!!!! • Bacteriostatic drugs require rapidly dividing microorganisms, they do not function well with bactericidal antibiotics!!!! • If both types are required then it is best to use them serially not in combination.

24. SERIAL AND COMBINATION ANTIBIOTIC THERAPY

25. Guidelines for antibiotics in periodontal therapy • Clinical diagnosis and situation dictate the need for ABC therapy. • Disease activity, measured by continuing attachment loss, purulent exudates… • Patient medical and dental status and current medication. • Microbiological plaque sampling. • Identification of which antibiotics were most effective…

26. Local Delivery Agents • Subgingival chlorhexidine . • Tetracycline containing fiber. • Subgingival doxycycline. • Subgingival minocycline. • Subgingival metronidazole.

27. Subgingival Chlorhexidine • A resorbable delivery system. • Biodegradable system that resorbs in 7-10 days. • No signs of staining were noted in any of the studies!!

28. Tetracycline containing Fiber • Tetracycline fibers with 12.7mg per 9 inches. • It was well tolerated in oral tissues and concentrations reach 1300µg/ml • No change in antibiotic resistance to tetracycline was found !!

29. Subgingival Doxycycline • A gel system using a syringe with 10% doxycycline (Atridox).

30. Subgingival Minocycline • A locally delivered sustained release form of minocycline microspheres (arestin). • The 2% minocycline is encapsulated into bioresorbable microspheres in gel carrier.

31. Subgingival Metronidazole • A topical medication containing an oil based metronidazole 25% dental gel. • Two 25% gel application at a 1-week interval have been used. • Bleeding on probing was reduced by 88% of cases.

32. Conclusions • Scaling and root planing are effective in reducing pocket depths. • When systemic antibiotics are used as adjuncts to scaling and root planing the evidence indicate that some antibiotics provide additional improvement. • There are extensive reviews of the local delivery agents available for periodontitis.