Rational Prescription of Antimicrobial Agents

1. Rational Prescription of Antimicrobial Agents Farjam MD PhD FUMS

2. Inappropriate use of antibioticsis a worldwideproblem • More than 50% of all medicines are prescribed, or soldinappropriately, and half of all patients fail to takemedicinescorrectly. • The overuse, underuse or misuse of medicinesharms people and wastesresources. • More than 50% of all countries do not implement basic policies to promote rational use of medicines. • In developing countries, lessthan 40% of patients in the public sector and 30% in the privatesector are treatedaccording to clinical guidelines.

3. Antibiotic Resistance: importance Financial loss Increase morbidity Increase mortality

4. Campaign to prevent antibiotic resistance Development of new antibiotics

5. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections

6. “The more you use, the more you lose”

7. درصد نسخ بيمه اي حاوي حداقل يک قلم آنتي بيوتيک در سالهاي 80، 81 و 82 در استان فارس (تا پايان آذرماه)

8. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections Hygiene measures: education and regulations for health care workers; public education

9. Facts: Microbes can spread from person-to-person; patient-to-patient & from health care personnel-to-patients Maneuvers to prevent these transmissions are the easiest & most cost-effective actions

10. “Gentlemen, wash your hands” IgnazPhilipp Semmelweis (1818-65) Chlorinated lime hand antisepsis

11. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections Hygiene measures: education and regulations for health care workers; public education Vaccination

12. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections Improvement of academic education Improvement of clinical knowledge and skills of medical sciences students Teaching (theoretical, practical) rational selection of antibiotics

13. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections Improvement of academic education Improvement of physicians’ capability to diagnose and treat infections Continuous medical education Well equipped laboratories

14. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections Improvement of academic education Improvement of physicians’ capability to diagnose and treat infections Education and regulations to avoid unnecessary invasive procedures & irrational drug prescription Organizing expert committees in hospitals

15. Campaign to prevent antibiotic resistance Development of new antibiotics Prevention of infections Improvement of academic education Improvement of physicians’ capability to diagnose and treat infections Education and regulations to avoid unnecessary invasive procedures & irrational drug prescription Organizing expert committees in hospitals Continuous research, inform specialists and community about the current situation and the results of modulations

17. Antimicrobial Therapy protocol • Formulate a clinical diagnosis of microbial infection • Obtain specimens for laboratory examination (if recommended, if possible) • Formulate a microbiological diagnosis • Determine the necessity for empiric therapy

18. Empiric Therapy • Recommended in: • Well defined microbial cause • Unable to get a suitable specimen • Dangerous conditions

19. Empiric therapy

20. Antimicrobial Therapy protocol • Formulate a clinical diagnosis of microbial infection • Obtain specimens for laboratory examination • Formulate a microbiological diagnosis • Determine the necessity for empiric therapy • Institute treatment

21. Efficacy

22. Microorganisms & Effective Antibiotics

23. Efficacy Age Dosage form Patient condition Check: Iran drug lists Iran drug information handbooks & text books http://fdo.behdasht.gov.ir/

24. Efficacy Age Dosage form Pregnancy Patient condition

26. Efficacy Age Dosage form Pregnancy Immune system Patient condition

28. Efficacy Age Dosage form Pregnancy Immune system Infection site Patient condition

29. Efficacy Age Dosage form Pregnancy Immune system Drug allergy Infection site Patient condition Liver

30. Hepatic disease & Pharmacokinetics

31. Impaired drug metabolism Many drugs are metabolized by liver but the hepatic reserve to metabolize drugs is very high No important changes in acute viral hepatitis Impaired metabolism in advanced chronic hepatic failure (dose adjustment is required for some drugs) Note: No correlation exists between enzymes level and capacity of of metabolism

32. Fluid overload & edema Exacerbation by NSAIDs, corticosteroides, …

33. Antibiotics & Liver Disease

34. Efficacy Age Dosage form Pregnancy Immune system Drug allergy Infection site Patient condition Liver Kidney

35. Renal disease & Pharmacokinetics

36. Important points RF is important for drugs that are not extensively metabolised or have active metabolites Some other pharmacokinetic parameters may change in RF Uremia may change some pathway of drug metabolisms The uremia may change (increase or decrease) the effects (desired or undesired) of some drugs

37. Antibiotics & Renal Disease

38. Efficacy Age Dosage form Pregnancy Immune system Drug allergy Infection site Patient condition Liver Kidney Lactation

39. Antibiotics in lactation

40. Efficacy Age Dosage form Pregnancy Immune system Drug allergy Infection site Patient condition Other drugs Liver Kidney Lactation

41. http://www.drugdigest.org

42. Efficacy Age Dosage form Pregnancy Immune system Drug allergy Infection site Patient condition Other drugs Liver Kidney Lactation Adverse effects

43. Adverse Reactions & Drug Interactions

44. Efficacy Age Dosage form Pregnancy Immune system Drug allergy Infection site Patient condition Liver Kidney Lactation Other drugs Adverse effects Duration of treatment Using frequency Taste & odour Cost

45. Appropriate use ofantibiotics in children

46. Considerations before prescribing • Is an antibiotic necessary? • What is the most appropriate antibiotic? • What dose, frequency, route and duration? • How to improvethe chances that the tretament will be effective?

47. Is an antibiotic necessary? • Useful only for the treatment of bacterial infections • Not all fevers are due to infection • Not all infections are due to bacteria • There is no evidence that antibiotics will prevent secondary bacterial infection in patients with viral infection • The treatment of certain infections might be better achieved with other means, such as surgery: • Debridement of local cellulitis in moderate CA-MRSA infections of the skin

48. Recommended therapy for CA-MRSA Barton M et al. Can J Infect Dis Med Microbiol 2006; 17(Suppl C): 1B-24B

49. Choice of antimicrobial agent Based on three main factors: • Etiological agent • Patient-related factors • Antibiotic-related factors

50. Antibiotic choice:Etiological agent • Be careful of the identification of the agent by the laboratory • Example: UTI • How was sample collected? • Contamination of sample is frequent, even in the best conditions • Consider the symptoms… • Consider the urinalysis…