Antibiotic Use

1
Antibiotic Use

• Dr Michael Francis
• Dr Pamela Snow

2
Outline

• 100-120 Introduction
• 120-200 Treatment of common infections
• 200-230 Clinical cases
• 230-300 Discussion How to deal with patients
  that demand antibiotics
• 300-330 Break
• 330-430 Community acquired pneumonia guidelines
  and QAs

3
Objectives

• Understand the scope of antibiotic misuse
• Understand some of the factors implicated
• Appreciate the evidence (and lack of) for
  antibiotics in common infections
• Review guidelines to help decision making
• Develop a framework for discussions with patients
  about antibiotics

4
Introduction

• 25.4 million prescriptions in Canada for oral abx
  (12 months from 1997/1998)
• It has been estimated that up to 50 of
  antibiotics are not indicated
• Rates of antibiotic prescribing have been related
  to prevalence of antibiotic resistance
• Widespread resistance to antibiotics would lead
  to a return to the pre-antibiotic era
• 4344 children with RTIs in Ontario (1997) 30
  diagnosed with colds

5
Total Antibiotic use in ambulatory care in 2001
www.ua.ac.be/ESAC
6
Canada vs. Scandinavia

• Similar re life expectancy, infant mortality
• Similar health care delivery structures
• Resistance to penicillin in Strep. Pneumonia
• Sweden 2
• Norway 5
• Denmark 3
• Finland 5.1
• Atlantic Canada 12 (2000)

7
Saskatchewan antibiotic prescriptions in 1995

• Percentage of patients given abx
• Acute URI 49
• Acute bronchitis or bronchiolitis 65
• Common cold 18
• Serous otitis media 32
• Acute laryngitis / croup 44
• Influenza 24
• Acute pharyngitis / tonsillitis 76

Wang et al. Clinical Infectious Diseases
199929155-60
8
Diagnostic Labeling in St. Johns

• Study in St. Johns / Mount Pearl in 1997-8
  examined abx prescriptions for 4218 patients
  seeing 73 GPs
• 949 of 4218 patients had newly acquired
  infections
• 77 diagnosed with RTIs
• 62 (451/727) of these were assigned a diagnosis
  with a potential bacterial cause

9
Diagnostic Labeling in St. Johns
Cold 15 given abx
LRTI 85 given abx
Sinusitis 89 given abx
Otitis Media 97 given abx
Pharyngitis 84 given abx
Hutchinson J et al. Canadian Family Physician
2001471217-24
10
Diagnoses in high and low prescribers
Number of diagnoses
Hutchinson J et al. Canadian Family Physician
2001471217-24
11

• Appropriateness of prescribing was
• assessed according to the Ontario Anti-
• infective guidelines (2nd edition)
• 19 wrong drug used
• 9 lower line drug available
• 59 appropriate abx use
• 13 abx not indicated

12
Pressure to Prescribe Antibiotics

• Patient demand
• Diagnostic uncertainty
• Inadequate medical education / CME
• Medicolegal concerns
• Pharmaceutical industry propaganda
• Physician remuneration

13
GP antibiotic prescribing in NL

• Analysis of 153 047 antibiotic prescriptions
• Physicians with relatively high prescription
  rates were more likely to be paid by fee-for
  service than salary
• Abx prescribing increased for both physician
  groups with the volume of patients

14
Reasons not to prescribe abx

• RESISTANCE
• Side effects minor and serious
• Cost to patient or health care system
• Prescribing antibiotics medicalises the illness

15
How to reverse the trend

• Patient education
• Posters in waiting rooms
• Discussion with patients
• Prescription pads for non-abx therapies

• Physician education
• Guidelines for Dx and Mx of common infections
• CME
• Feedback on prescribing rates

16
Country-wide solutions to the antibiotic problem

• Longer patents on new abx to encourage
  development
• Public-funded research
• Price abx out of range for trivial infections

17
URTI

• Mainly viral Antibiotic not recommended
• Sinus, pharyngeal and lower airway symptoms may
  be present but not prominent
• Severe symptoms with myalgia and fatigue
  consider influenza or para-influenza

18
Respiratory Tract Infections

• Community acquired pneumonia incidence 10-20 per
  1000 person-years
• Common cold 2-4 per person per year
• Acute sinusitis complicates 0.5 of colds (10-20
  /1000 person-years)

19
URTI

• Symptoms and signs of viral colds overlap with
  bacterial pharyngitis, sinusitis, bronchitis and
  otitis media
• Largest study of respiratory illness the Tecumseh
  study of 1965-69
• 1419 specimens obtained
• Gp A strep present in 2.8
• Where an organism was cultured 11 were Gp A
  strep

Monto AS, Cavallaro JJ. American Journal of
Epidemiology 197194280-9
20
Acute Pharyngitis

• 1-2 of all visits to physician
• In adults 10 Gp A Strep
• Reasons to consider antibiotics
• ? Prevent Rheumatic fever
• ? Prevent Streptococcal glomerulonephritis
• ? Reduce complications
• ? Reduce symptoms

21
Acute Rheumatic Fever and GAS Pharyngitis

• Rheumatic fever uncommon
• Early randomised trials found relative risk of
  0.28 for penicillin treatment
• Applied to the incidence of rheumatic fever in
  1994 NNT is 3000 4000.

22
Poststreptococcal Glomerulonephritis

• Very rare
• No evidence that antibiotics reduce incidence

23
Antibiotics reduce symptoms in GAS Pharyngitis

• If instituted within 2-3 days of symptom onset,
  reduce symptoms 1-2 days sooner
• ? Reduction in supparative complications

24
Pharyngitis Scoring System

• Temperature gt38ºC 1
• No cough 1
• Tender anterior cervical adenopathy 1
• Tonsillar swelling or exudate 1
• Age 3-14 years 1
• Age 45 years -1
• Score 2-3 culture Score 4 treat

25
Scoring System in Canadian Family Practice Adults
McIsaac WJ et al. CMAJ 2000163811-5
26
Rapid Antigen Tests

• Sensitivity 58-96
• Specificity 63-100
• Can be used on intermediate scores
• Cost
• Physicians frequently prescribe antibiotics even
  when results negative

27
Pharyngitis

• Manage according to scoring criteria
• All patients should be advised re anti-pyretics,
  analgesics and supportive care

28
Treatment of Streptococcal Pharyngitis

• First Line Penicillin V
• Also amoxicillin or pivampicillin in children
• Second Line Erythromycin
• Third Line
• Cephalosporin e.g. cephalexin, cefixime
• Clarithromycin, Azithromycin

29
Otitis Media

• 80-90 resolve spontaneously
• Organisms
• Viral
• S. pneumoniae
• H. influenzae
• M. Catarrhalis
• Group A Strep
• S. aureus

30
Evidence for antibiotics in otitis media

• Review of 9 RCTs abx vs placebo in children 7
  months 15 years old
• Pain at 24 hours no different with abx (n717 4
  studies)
• 2-7 days after presentation pain reduced with abx
  (RR 0.67 CI 0.53-0.85)
• ARR 4.8
• Fewer children developed contralateral otitis
  media with abx (RR 0.65 CI 0.45-0.94)
• ARR5.9

Glassziou PP et al. Cochrane Review Antibiotics
for acute otitis media in children. CD000219
2000
31
Evidence for antibiotics in otitis media

• Only 1/1962 children developed mastoiditis (and
  they has been treated with penicillin)
• Adverse effects were increased with abx (RR 1.55
  CI 1.11-2.16)
• No significant difference in
• Subsequent attack of acute otitis media
• Abnormal tympanometry at 1/12 or 3/12

32
Prescribing Strategies for Otitis Media

• UK study of 315 children 6/12 10 years
• Patients randomised to immediate prescription or
  delayed abx (72h)
• Reduced illness duration, fewer disturbed nights
• Less diarrhea in delayed group (19 vs 9)
• Only 36/150 (24) of the delayed group used abx

Little et al. BMJ 2001322336-42
33
Otitis Media

• Children under age 6/12 Treat
• 6/12 2 year olds Watchful waiting for 2-3 days
• if child monitored and 24h follow up arranged
• 2 years Watchful waiting for 2-3 days

34
Acute Otitis Media

• First Line Amoxicillin
• Second Line
• Clavulin
• Clarithromycin, azithromycin
• Septra
• Cefuroxime, Cefixime
• Pivampicillin
• Erythromycin Sulfisoxazole (Children)

35
Acute Sinusitis

• 14 of Americans claim to have had sinusitis
• lt2 of viral URTIs complicated by bacterial
  sinusitis
• Most resolve within 5-7 days without abx
• Organisms
• Viral
• S. pneumoniae
• H. influenzae
• M. Catarrhalis
• Group A Strep
• S. aureus

36
Acute Sinusitis

• Consider abx if adult with URTI with no
  improvement / deteriorating after 7 days and
  other features
• Useful diagnostic factors
• Purulent nasal discharge
• Maxillary tooth or facial pain (especially
  unilateral)
• Second sickening
• Not useful in distinguishing viral from bacterial
  sinusitis
• Generalised facial pain or tenderness
• Post-nasal discharge
• Headache
• Cough

37
Antibiotics for acute sinusitis?

• A review of five RCTs looked at the effect of abx
• Cured abx 47 controls 32
• Improved or cured abx 81 controls 66
• Two placebo-controlled trials in primary care
  found no significant clinical effect of abx

38
Acute Sinusitis

• First line Amoxicillin
• Second line
• Pivampicillin
• Clavulin
• Doxycycline
• Cephalosporin e.g. cefuroxime, cefixime
• Clarithromycin, Azithromycin
• Erythromycin / Sulfisoxazole (Children)
• Septra
• Third line gatifloxacin, levofloxacin,
  moxifloxacin (adults)

39
Treatment of sinusitis

• Alpha adrenergic agents
• Mucolytic agents
• Corticosteroids (drops or sprays)
• Antihistamines

40
Acute Bronchitis

• 5 of American adults report episode/year
• Average of 2-3 days work lost per episode
• In adults 90 are viral
• Bacteria M. pneumoniae, C. pneumoniae, B.
  pertussis
• In children almost all are viral
• Symptoms 1-3 weeks cough /- sputum
• In non-elderly adults with uncomplicated
  infection No abx
• Main concern is ruling out pneumonia

41
Pneumonia unlikely if

• Normal chest examination
• Normal vitals
• Pulse lt100
• Resps lt24
• Temp lt38

42
Treatment of Acute Bronchitis

• First line No antibiotic
• Second line Erythromycin, doxycycline
• Third line Tetracycline, clarithromycin,
  azithromycin
• Inhaled beta-agonists may help

43
Counselling patients with acute bronchitis

• Realistic expectation of duration (10-14 days)
• Refer to the cough illness as a chest cold
  rather than bronchitis
• Personalise risks of antibiotics
• Ineffectiveness of antibiotics
• Risk of carriage of resistant bacteria

44
Summary of abx for RTIs

• URTI No
• Pharyngitis Select cases
• Acute otitis media Select cases watch and wait
  for rest
• Sinusitis Select cases
• Bronchitis No

45
Acute exacerbation of COPD

• 50 Non-bacterial
• Consider abx if increased sputum volume,
  purulence and SOB (2/3)
• Antibiotic options are dependant on the presence
  of risk factors
• Poor lung function (FEV150)
• Age gt65
• Comorbid illness (CHF, DM, CRF, liver disease)
• Chronic steroid use
• Abx in previous 3/12
• 4 exacerbations per year

46
Exacerbation COPD No risk factors

• First line
• Amoxicillin
• Septra
• Tetracycline
• Second line
• Doxycycline
• Clavulin
• Clarithromycin, azithromycin
• Cephalosporin e.g. cefuroxime

47
Exacerbation COPD Risk factors

• Clavulin
• Clarithromycin, azithromycin
• Cephalosporin e.g. cefuroxime
• Gatifloxacin, levofloxacin, moxifloxacin

48
References

• Jim Hutchinson
• Cochrane Library
• Clinical Evidence
• Orange Book

49
Case 1

• Crying 18 month old with 24 hours of fever of
  38C
• Some coryzal symptoms
• Although miserable, the child does not appear
  toxic and has normal vital signs
• Examination entirely normal except for bilateral
  diffusely red tympanic membranes. They are not
  bulging and the light reflex is normal
• What would you do?
• Would it make any difference if the child was 3
  years old?

50
Case 2

• A 9 year old has a cough and rhinorrhea of two
  days
• He has a temperature of 38C
• Ears, throat and chest examination are normal
• What would you do?

51
Case 3

• A 25 year old complains of 7 days of cough,
  purulent nasal discharge, sore throat and
  bilateral facial pain.
• PMH is remarkable only for one previous episode
  of sinusitis
• There is no fever and no abnormality on
  examination
• What would you do?
• What if the symptoms were only of nasal discharge
  and facial pain?

52
Case 4

• A 15 year old complains of a two week history of
  sore throat, malaise and loss of appetite.
• There are no coryzal symptoms
• He has completed a 7 day course of penicillin,
  which his mother said improved the symptoms until
  it stopped 2 days ago
• Examination reveals no fever but bilateral
  enlarged tonsils with exudate and tender cervical
  adenopathy
• What would you do?

53
Case 5

• A six year old presents with a two day history of
  fever, cough and sore throat
• Examination finds a temperature of 38.1ºC, and
  bilateral enlarged tonsils with exudate
• There is no lymphadenopathy
• What would you do?

54
Case 6

• 55 year old non-smoker with a two week history of
  cough productive of purulent sputum
• No SOB, fever, or coryzal symptoms
• Pulse 94, RR 20, Temp 37.2C, BP 140/75
• Normal physical examination
• What would you do?
• What if the patient were a smoker?

55
Case 7

• 6 year old child with a cough
• No fever, and no respiratory distress but
  auscultation reveals crackles in the left base
• What would you do?

56
Pressure to Prescribe Antibiotics

• Patient demand
• Diagnostic uncertainty
• Inadequate medical education / CME
• Medicolegal concerns
• Pharmaceutical industry propaganda
• Physician remuneration

57
Patients that demand antibiotics

• Too busy to be sick
• Conditioned by previous inappropriate prescribing
• Wedding / holiday excuse
• Doctors are poor at predicting which patients
  expect antibiotics

58
Talking to patients about antibiotic use

• Dont assume patients want antibiotics
• There may be a role for empowering patients to
  make decisions here
• Patients often view antibiotics as totally safe
  discussions can be easier if this view is
  challenged

59
Empower Patient!

• Quote patient some simple statistics to enable
  their informed choice
• Framing is key
• Chance of improvement with sore throat 1-2
• Chance of side effect 15

60
Deferred Prescriptions

• This is a reasonable option
• Has been studies not everyone takes the
  prescription