1. Pharmacology Module #4 Drug Control of Infection

2. Chapter 7 Antiinfective Agents

3. Definitions. Anti- what????? Antiinfective Destroy infections Antibacterial Destroy or suppress growth of bacteria Antibiotic Chemical produced by a microorganism that can destroy or suppress bacteria Antimicrobial Destroy or suppress growth of microorganisms Antifungal Destroys fungi Antiviral Destroys viruses

4. Definitions cont. Bactericidal Ability to kill bacteria Bacteriostatic Inhibit or retard bacterial growth Infection Invasion of body by pathogenic microorganisms Tissue reaction Resistance Ability of bacteria to resist effects of antiinfective agents Spectrum Range of a drug’s activity Narrow or broad

5. More Definitions… Superinfection Proliferation of microorganisms different from those causing the original infection Synergism 2 antibiotics that when combined, produce more effect than expected Antagonism 2 antibiotics that when combined, produce less effect than each agent alone

6. Synergism Vs. Antagonism Synergism 1+ 1= more than 2 DO Example: Bactericidal Note: addition of 2 bacteriostatic agent is merely additive 1+1=2 DO Antagonism 1 + 1= less than 2 DO NOT Example: Bactericidal Bacteriostatic

7. Dental Infection “Evolution” Stage 1- gram +, aerobic microbes Drug of choice Penicillin VK If allergic- erythromycin or clindamycin Stage 2- also includes gram – anaerobes (mixed infection) Pen VK or erythryomycin Stage 3- predominantly anaerobes Metronidazole or clindamycin

8. Antibiotics-To use or not to use?? Overuse of antibiotics is to blame for resistant strains of bacteria Incision and drainage is preferred method of treatment for infection (no prescription of antibacterial drugs) normal immune system localized infection

9. Video- YouTube Clip Resistance https://www.youtube.com/watch?v=AYvX8 tnCM9s https://www.youtube.com/watch?v=AYvX8 tnCM9s

10. Culture and Sensitivity Testing Culturing Growing bacteria in a controlled environment Sensitivity testing Exposing bacteria to certain antiinfective agents to determine sensitivity or resistance Determines appropriate treatment of infections

11. Antimicrobial Use in Dentistry Conditions ANUG periodontal abscess localized juvenile periodontitis adult periodontitis rapidly advancing periodontitis abscess, pericoronitis osteomyelitis aerobes not sensitive to penicillin anaerobes not sensitive to penicillin

12. Which antibiotic to prescribe? ANUG: Pen VK, Amoxicillin Periodontal abscess: Pen VK Juvenile periodontitis: Doxycycline, tetracycline Adult periodontitis: No drug treatment used

13. Which antibiotic to prescribe? Rapidly advancing periodontitis: Doxycycline, tetracycline, metronidazole Soft tissue oral infection: Pen VK, Amoxil Osteomyelitis: Pen VK, Amoxil

14. Which antibiotic to prescribe? Aerobic mixed infection insensitive to penicillin: Amoxicillin with clavulanate Anaerobic mixed infection insensitive to penicillin: Metronidazole, clindamycin

15. Dental Uses of Antibiotics Therapeutic Periodontal disease Soft tissue infections Prophylactic Artificial heart valves History of infective endocarditis Total joint replacement

16. Updated Recommendations American Heart Association website American Dental Association website Drug of choice is Amoxicillin Alternatives: Clindamycin Azithromycin

17. Prophylactic Drug Regimens 1 hour before procedure No allergy Amoxicillin 2000 mg Allergy to penicillins Clindamycin 600 mg Azithromycin 500 mg

18. National Board Question The drug of choice for a person allergic to penicillin for prophylaxis premedication is a. Erythromycin b. Azithromycin c. Ampicillin d. Amoxicillin

19. Antibiotic Prophylaxis for Dental Procedures Recommended: Procedures producing significant bleeding Oral prophylaxis Scaling and root planing

20. Antibiotic Prophylaxis for Dental Procedures Not necessary for: Anesthetic injection through noninfected tissue Taking impressions Taking dental radiographs Sealant placement Fluoride treatments

21. Adverse Reactions Superinfection Potential overgrowth of an organism different from the original infection cause Resistant More common with wide spectrum drugs More common if duration of use is long Allergies Hives to anaphylaxis Penicillins and cephalosporins

22. Adverse Reactions cont. GI tract Stomach pain, increased motility, diarrhea Pseudeomembranous colitis Helps to take with food Pregnancy Limited use- consult obstetrician Pen VK/ erythromycin- OK Tetracyclines- teratogenic

23. Drug Interactions Oral contraceptives May reduce effectiveness of birth control Anticoagulants May increase anticoagulant effect More prone to bleeding/ hemorrhage Other antibiotics Antagonistic effect- decreases effect of both Bacteriostatic and bactericidal

24. National Board Question A two-year-old child has developed an infection requiring an antibiotic. Which of the following would be the least desirable choice? a. Erythromycin b. Tetracycline c. Cephaloxin d. Ampicillin

25. Terms Hypersensitivity Most common drug - penicillin Most common manifestation – rash Cross-hypersensitivity with cephalosporins Penicillinase Bacteria produce this enzyme to break down penicillin Adding clavulanic acid to amoxicillin (Augmentin) prevents penicillinase from breaking it down.

26. Concepts Mechanisms of action of antibiotics: Inhibit cell wall synthesis Inhibit protein synthesis Make cell wall more permeable Spectrum Wide or narrow Bacteriostatic or bactericidal

27. Classifying Anti-Infectives Categorize by: Spectrum or organism affected Broad Narrow Fungus Virus Bacteriostatic or bactericidal Mechanism of action See chart attached to objectives

28. Specific Antibiotics Penicillins Macrolides Tetracyclines Clindamycin Metronidazole Cephalosporins Vancomycin Aminoglycosides Sulfonomides Sulfamethoxazole/ trimethoprim Antituberculosis agents Topicals

29. Penicillin Mechanism of action Inhibits cell wall synthesis Bactericidal Spectrum Narrow Resistance Some bacteria produce penicillinase which breaks down penicillin rendering it ineffective

30. Penicillinase-resistant Penicillins Cloxacillin Dicloxacillin For infections that are penicillinase- producing staphylococci only More side effects Not for people allergic to penicillin

31. Ampicillins Examples: ampicillin, amoxicillin (Augmentin, Amoxil, Trimox) Not penicillinase resistant (Augmentin is) Gram + cocci and enterococci Better absorbed, requires less frequent dosing, absorption not impaired by food May cause allergic reactions

32. Macrolides Examples: erythromycin, clarithromycin, azithromycin Mechanism of action Inhibits protein synthesis Bacteriostatic Spectrum Narrow

33. Macrolides cont. Adverse reactions: GI upset Jaundice Uses: Patients allergic to penicillin Effective against aerobes

34. Tetracyclines Examples: tetracycline, doxycycline Mechanism of action Inhibits protein synthesis Bacteriostatic Spectrum Wide Aerobes and anaerobes

35. Adverse Effects of Tetracycline GI Nausea, vomiting, xerostomia, superinfection- candiasis Teeth and bones Permanent tooth discoloration Incorporated into tooth structure Do not give during pregnancy or children less than 9 years old Enamel hypoplasia

36. Clindamycin Mechanism of action Inhibits protein synthesis Bacteriostatic Spectrum Wide Uses Gram + and anaerobes

37. Clindamycin Adverse Effects GI Usual- nausea, vomiting, diarrhea, cramping Severe- pseudomembranous colitis (persistent diarrhea and passage of blood and mucous) can be fatal Superinfection Candidiasis Allergy

38. Metronidazole Mechanism of action Bacteriocidal Spectrum Anaerobes Resistance is rare Uses Treatment of NUG

39. Metronidazole Drug Interactions Alcohol Causes headache, nausea, vomiting, cramps Disulfiram= Antabuse reaction

40. Cephalosporins Mechanism of action Inhibits cell wall synthesis Bactericidal Spectrum Wide Uses Infections resistant to penicillin Gram – organisms

41. Vancomycin Spectrum Narrow Uses Non-dental Eradicate bacteria in GI tract

42. Aminoglycosides Spectrum Wide Adverse effects Ototoxicity Toxic to 8 th cranial nerve- can lead to auditory and vestibular (inner ear) disturbances

43. Sulfonamides Mechanism of action Interferes with folate metabolism Spectrum Wide Uses Non-dental, ear infections Adverse effects Renal crystallization- drink plenty of water

44. Sulfamethoxazole/ Trimethoprim Combination antimicrobial drug Bactrim Uses Ear infections in children

45. Antituberculosis Agents Tuberculosis (TB) Can be contracted in dental setting Drugs used for treatment: Isoniazid Rifampin Pyrainamide Ethambutol NOTE: Used together b/c of resistance

46. Topical Antibiotics Applied to the skin Example: Neosporin Neomycin, polymyxin, and bacitracin

47. Review of Mechanisms of Action Bactericidal or bacteriostatic Inhibit bacterial cell wall synthesis bactericidal Inhibit bacterial protein synthesis bacteriostatic Inhibit nucleic acid synthesis RNA & DNA Interfere with folate metabolism anti-metabolites

48. Claire Cranberry No Allergy to penicillin Classifications tetracycline – antibiotic Sudafed – alpha adrenergic agonist candadiasis tetracycline & sudafed both could be involved nystatin or clotrimazole clindamycin 600 mg (3 tabs) 1 h before appt. NSAID?

49. Review Which antibiotic causes damage to the 8 th cranial nerve? aminoglycocides

50. Review Which antibiotic causes pseudomembranous colitits? Clindamycin Which antibiotic causes a disulfram-like reaction? metronidazole

51. Review Name 4 broad spectrum antibacterial agents. Aminoglycocides Cephalosporin Clindamycin Sulfonamides Tetracycline

52. Review Which antibiotic has a cross- hypersensitivity with penicillin? Cephalosporin

53. Matching- Method of action Inhibit cell wall synthesis Inhibit protein synthesis Interfere with folate metabolism Tetracycline Erythromycin Penicillin Cephalosporin Sulfonamide Amoxicillin

54. Chapter 8 Antifungal and Antiviral Agents

55. Antifungal Agents Used to treat fungal infections Example: candidiasis

56. Nystatin and Clotrimazole Mechanism of action Alteration of cell membrane permeability Nystatin Available as a suspension, lozenge, or cream Clotrimazole Available as a troche or cream

57. Nystatin and Clotrimazole Directions for patient: Suspension Swish, swirl, spit or swallow 5 ml four x daily Should remain in mouth for 2 mins. Troches/ lozenges Dissolve in mouth slowly Take all of the medication

58. Amphotericin B Uses severe fungal infections- systemic Adverse reactions Hypokalemia, headache, chills, fever, malaise, muscle and joint pain, gastric complaints, nephrotoxicity

59. Antiviral Agents Used to treat viral infections Examples: HIV, herpes

60. Treatment of Herpes Drugs Acyclovir, docosanol, penciclovir Adverse reactions Burning skin, headache, dizziness, GI upset Uses Genital and oral herpetic lesions

61. Treatment of HIV Nucleoside analogs Zidovudine (AZT, ZDV) Terminates the synthesis of viral DNA Protease inhibitors Indinavir Prevent maturation of HIV-infected cells

62. Chapter 13 Oral Conditions and Their Treatment

63. Herpes Simplex Labialis AKA cold sore, fever blister Antiviral agents Acyclovir Valacyclovir Penicyclovir

64. Candidiasis Antifungal agents Nystatin suspension Clotrimazole troches/ lozenges

65. Pericornitis/ Alveolar Osteitis Treatment: Rinsing with saline water Debridement Pack placement Analgesics Supportive therapy If infection present, prescribe antibiotics