أستاذنا الدكتور سمير الأنصاري

1. Sherif Anis, MD
Assistant professor of Anesthesia & ICU
Ain Shams University

2. Objectives
 Identify the appropriate 1st and 2nd line antibiotic for
empiric treatment of common bacterial infections in the
community and hospital settings
 Tailor the choice of antibiotic based on unique patient risk
factors
 Reducing bacterial resistance
 Identify resources for information on safe, effective
treatment

3. Conventional antibiotics
 Penicillins
 Cephalosporins
 Carbapenems
 Quinolones
 Aminoglycosides
 Macrolides
 Tetracyclines
 Nitrofurantoin,
metronidazole,
clindamycin,
vancomycin, teicoplanin,
cotrimoxazole, fusidic
acid, etc
 Isoniazid, pyrazinamide,
ethambutol, rifampin,
cycloserine, etc

4. Penicillins
 Penicillin G
 Still useful for a number of diseases (e.g. meningitis, syphilis)
 Cloxacillin
 For MSSA infections
 Ampicillin, amoxicillin
 Active vs. Gram-positive (not MSSA), Gram-negative organisms
 Augmentin, Unasyn
 Broad spectrum, covers Gram-positive, Gram-negative and
anaerobes
 Piperacillin, Tazocin, Timentin
 Are active vs. Pseudomonas

5. Cephalosporins
 Cefazolin, cephalexin
 Active vs. Gram-positive organisms including MSSA
 Cefuroxime, Cefaclor
 Covers some Gram-negative organisms
 Cefotaxime, Ceftriaxone
 Broad spectrum, enhanced activity towards Gram-
negative organisms
 Ceftazidime, Cefepime, Sulperazon
 Additive Pseudomonas coverage

6. Carbapenems
 Imipenem
 Broad spectrum, covers Gram-positive, Gram-negative
(including ESBL-producing strains), Pseudomonas and
anaerobes
 Meropenem
 Less seizure-inducing potential, can be used to treat
CNS infections
 Ertapenem
 Lacks activity vs. Acinetobacter and Pseudomonas
 Has limited activity against penicillin-resistant
pneumococci

7. Quinolones
 Ciprofloxacin
 Active vs. MSSA, Gram-negative and Pseudomonas
 Levofloxacin
 Has activity vs. Streptococcus pneumoniae, but slightly
less active towards Pseudomonas compared to
ciprofloxacin
 Moxifloxacin
 Has activity vs. anaerobes but less active towards
Pseudomonas

8. Aminoglycosides
 Active vs. some Gram-positive and Gram-negative
organisms
 Gentamicin
 Active vs. Pseudomonas
 Tobramycin
 More active vs. Pseudomonas than gentamicin
 Shows less activity against certain other Gram-negative bacteria
 Amikacin
 More stable to enzymes, used in severe infections by gentamicin-
resistant organisms
 Streptomycin
 Used for tuberculosis

9. Macrolides
 Erythromycin
 Active vs. Gram-positive organisms, atypicals
 GI side effects
 Clarithromycin
 Slightly greater activity than erythromycin
 Azithromycin
 Slightly less active than erythromycin vs. Gram-positive
but enhanced activity vs. some Gram-negative
organisms

10. Tetracyclines
 Drug of choice in infections caused by Chlamydia,
Rickettsia, Brucella and Lyme disease
 Value has decreased due to increasing bacterial
resistance
 Tetracycline
 Role in Helicobacter pylori eradication (less frequently
used than other antibiotics)
 Doxycycline
 Once daily
 Minocycline
 Broader spectrum

11. Other antibiotics
 Clindamycin
 Vs. Gram-positive cocci and anaerobes
 Metronidazole
 Vs. anaerobes
 Preferred therapy in antibiotic associated diarrhoea
(Clostridium difficile) than oral vancomycin, although
unlicenced
 Vancomycin, teicoplanin
 For Gram-positive organisms (including MRSA)

12. Other antibiotics
 Cotrimoxazole
 Role in uncomplicated UTI, UTI prophylaxis, acute
exacerbations of chronic bronchitis
 Pneumocystis carinii (now jiroveci) infections
 Nitrofurantoin
 For UTI, prophylaxis vs. UTI
 Fusidic acid, rifampin
 For penicillin-resistant staphylococci
 Not for monotherapy due to risk of emergence of
resistance

13. Classes
 Bacteriostatic vs Bactericidal
 Narrow vs Broad spectrum

14. Classes
 Bacteriostatic
 Aminoglycosides (Streptomycin, Amikacin,
Gentamicin, Tobramycin)
 Lincosamides (Clindamycin)
 Macrolides (Azithromycin)
 Tetracyclines (Doxycycline)

15. Bactericidal
 Aminoglycosides
 Glycopeptides
(Vancomycin)
 Lipopeptides
(Daptomycin)
 Nitrofurans
 Metronidazole
 Penicillins
 Cephalosporins
 Monobactams
(Aztreonam)
 Carbapenems
(Meropenem)
 Quinolones
 Sulfonamides

16. Broad Spectrum
 Amoxicillin/clavulanate (Augmentin)
 Ampicillin/sulbactam (Unasyn)
 Piperacillin/tazobactam (Tazocin)
 Ticarcillin/clavulanate (Timentin)

17. Newer Classes
 Cyclic lipopeptides (daptomycin)
 Bactericidal against Gram-positive, including MRSA
 Glycylcyclines (tigecycline)
 Bacteriostatic against Gram-pos, Gram-neg and MRSA
 Oxazolidinones (linezolid)
 Bacteriostatic and bactericidal against Gram-positive, including
MRSA, VRE

18. Good news vs. bad news
 Good news
 A few novel antibiotics have shown promising results / are
undergoing clinical studies
 Bad news
 As immunosuppressive diseases and use of immunosuppressive
agents become more prevalent, opportunistic infections becomes
more common, esp. by organisms rarely encountered previously
 Diseases: e.g. HIV, leukemia
 Drugs: e.g. in solid organ transplants, bone marrow transplants,
rheumatoid disorders
 Development of bacterial resistance to antibiotics is much faster
than research and development of new antibiotics

19. Principles on choosing an antibiotic
for empiric therapy
 As best possible, attempt to localize the site of
infection
 Do a good exam!!!
 Occam’s razor
 “Plurality must not be posited without necessity”
 Use only one diagnosis whenever possible

20. Gram-positive superbugs
Resistant Gram-positive bacteria terminology
PRSP Penicillin resistant Streptococcus pneumoniae
MDRSP Multidrug resistant Streptococcus pneumoniae
MRSA Methicillin resistant Staphylococcus aureus
VRSA Vancomycin resistant Staphylococcus aureus
VISA (GISA) Vancomycin (Glycopeptide) intermediate
Staphylococcus aureus
VRE (GRE) Vancomycin (Glycopeptide) resistant Enterococcus

21. Case 1
 F/74, DM on oral hypoglycemic drugs
 Presented with fever and malaise, cough with sputum,
tachypnea; chest X-ray revealed bilateral infiltrates
 Travel history, occupation, contact and clustering non-
remarkable
 Received a course of amoxicillin for urinary tract infection
10 weeks ago
 Diagnosis: Community-acquired pneumonia
 Question
 What is the empirical treatment for CAP?

22. Chest X-ray

23. Chest X-ray

24. Community-acquired pneumonia (CAP)
 Microbiology
 “Typical” organisms
 Streptococcus pneumoniae
 Haemophilus influenzae
 Moraxella catarrhalis
 “Atypical” organisms
 Chlamydia pneumoniae
 Mycoplasma pneumoniae
 Legionella pneumophilia
 Empirical therapy
 Beta-lactams to cover typical organisms
 Doxycycline / macrolides to cover atypical organisms
 Respiratory fluoroquinolones (levo, moxi) for beta-lactam allergy

25. Community-acquired pneumonia (CAP)
 Empirical therapy
 CAP, out-patient
 Augmentin/Unasyn PO ± macrolide PO
 Amoxicillin PO + clarithromycin / azithromycin PO
 CAP, hospitalized in general ward
 Augmentin / Unasyn IV/PO ± macrolide
 Cefotaxime / ceftriaxone IV ± macrolide
 CAP, hospitalized in ICU for serious disease
 Add cover to Gram-negative enterics
 Tazocin / cefotaxime / ceftriaxone IV + macrolide
 Cefepime IV + macrolide

26. Community-acquired pneumonia (CAP)
 Empirical therapy
 Modifying factors
 Allergy to beta-lactams
 Fluoroquinolone (levofloxacin / moxifloxacin)
 Aspiration likely: anaerobes should be covered
 Augmentin / Unasyn / Tazocin already provide coverage
 Cephalosporins (except Sulperazon) is inactive
 Moxifloxacin
 Bronchiectasis: Pseudomonas cover essential
 Tazocin / Timentin / cefepime + macrolide
 Fluoroquinolone + aminoglycoside

27. Case 1
 Patient was started on Augmentin +
clarithromycin empirically
 3 days later, fever persisted, chest X-ray showed
progressive pneumonia
 Endotracheal aspirate (WBC +++, few epithelial
cells) grew heavy Streptococcus pneumoniae, with
penicillin MIC > 4mcg/ml
 Questions
 Risk factors for penicillin-resistant S. pneumoniae?
 Appropriate management in this case?

28. Penicillin resistant Streptococcus pneumoniae
(PRSP)
 Risk factors
 Age > 65 years
 Beta-lactam therapy in past 3 months
 Alcoholism
 Multiple medical comorbidities (e.g.
immunosuppressive illness or medications)
 Exposure to a child in a day care centre

29. Penicillin resistant Streptococcus pneumoniae
(PRSP)
 If susceptible, penicillin group is the drug of
choice for Streptococcus pneumoniae
 Check susceptibility and MIC if resistant to
penicillin
 Penicillin susceptible (MIC  0.1 mcg/ml)
 Penicillin G, amoxicillin
 Penicillin resistant (0.1< MIC 1.0 mcg/ml)
 High dose penicillin G or ampicillin, cefotaxime /
ceftriaxone

30. Penicillin resistant Streptococcus pneumoniae
(PRSP)
 Penicillin resistant (MIC > 2.0 mcg/ml)
 Vancomycin  rifampin
 High dose cefotaxime tried in meningitis
 Non-meningeal infection: cefotaxime / ceftriaxone, high
dose ampicillin, carbapenems, or fluoroquinolone
(levofloxacin, moxifloxacin)
 Multidrug resistant (MDRSP, resistant to any 2 of
the following: penicillins, erythromycin,
tetracycline, macrolides, cotrimoxazole)
 Vancomycin  rifampin
 Clindamycin, levofloxacin, moxifloxacin could be tried

31. Penicillin resistant Streptococcus pneumoniae
(PRSP)
 Any alternative for PRSP / MDRSP in respiratory tract
infection?
 Newer agents
 Telithromycin (Ketek®)
 Linezolid (Zyvox®)

32. Telithromycin (Ketek®)
 A ketolide (structurally related to macrolides)
 Spectrum of activity
 Group A, B, C and G Streptococci, Streptococcus
pneumoniae (including multidrug resistant strains),
MSSA
 Listeria monocytogenes, Neisseria meningitidis,
Moraxella catarrhalis, Haemophilus influenzae
 Legionella, Chlamydia, Mycoplasma
 No activity vs. MRSA, GRE, or any enteric gram-negative
bacteria
 Indications
 Mild to moderate community acquired pneumonia

33. Linezolid (Zyvox®)
 An oxazolidinedione
 Spectrum of activity and indications
 Vancomycin-Resistant Enterococcus faecium infections, including
cases with concurrent bacteremia
 Nosocomial pneumonia caused by MSSA or MRSA or Strep
pneumoniae (including MDRSP)
 Complicated skin and skin structure infections, including diabetic
foot infections, without concomitant osteomyelitis, caused by
MSSA or MRSA, Strep pyogenes, or Strep agalactiae
 Uncomplicated skin and skin structure infections caused by MSSA
or Strep pyogenes.
 Community-acquired pneumonia caused by Strep pneumoniae
(including MDRSP), including cases with concurrent bacteremia, or
MSSA

34. Case 2
 M/56
 Presented with skin redness, warmth, swelling,
tenderness on his right lower limb, a pocket of fluid
palpated
 Diagnosis: cellulitis with pus formation
 Question
 Empirical treatment?

35. Skin and soft tissue infection
 Cellulitis
 Microbiology
 Staphylococcus, Streptococci
 Streptococci more likely when cellulitis is well
demarcated and there are no pockets of pus or evidence
of vein thrombosis

36. Staphylococcus aureus
 If susceptible, penicillinase-resistant penicillins are the
drugs of choice for methicillin-susceptible Staphylococcus
aureus (MSSA)
 Drug of choice
 Cloxacillin, flucloxacillin
 Cefazolin, cephalexin (penicillin allergic but tolerate cephs)
 With beta-lactamase inhibitor
 As two-agent combination in Augmentin, Unasyn
 Erythromycin, clindamycin (if penicillin allergic)
 The above antibiotics also have good activity vs.
Streptococci

37. Case 2
 Skin tenderness and redness did not appear to
improve despite Augmentin has been given
 Pus grew MRSA after 2 days
 R to methicillin, cephalothin, erythromycin
 S to clindamycin, vancomycin, gentamicin,
cotrimoxazole
 Patient is clinically stable
 Questions
 What is the drug of choice in MRSA infection?
 Can clindamycin be used in this case?

38. Methicillin resistant Staphylococcus aureus
(MRSA)
 Healthcare-associated
 Endemic in hospitals, old age
homes
 Risk factors
 Hospitalization in previous 1
year
 Recent surgery
 Old age home residence
 Renal dialysis
 Exposure to invasive devices
 Employment in a healthcare
institute
 Community-associated
 Do not have usual risk
factors associated with HA-
MRSA
 More common in the
following in overseas
countries
 Children with chronic skin
condition
 Prisoners
 Military personnel
 Aboriginals
 Injection drug users
 The homeless
 Contact sports athletes

39. Methicillin resistant Staphylococcus aureus
(MRSA)
 Healthcare-associated
 Multiresistant to
 Clindamycin
 Aminoglycosides
 Tetracyclines
 Fluoroquinolones
 Community-associated
 Often remains susceptible
to
 Clindamycin
 Aminoglycosides
 Tetracyclines
 Fluoroquinolones
 More associated with
skin/soft tissue infections
and severe necrotizing
pneumonia

40. Methicillin resistant Staphylococcus aureus
(MRSA)
 Obtain culture for susceptibility testing right
before empirical antibiotics!
 Treatment (as per Sanford Guide 37th ed)
 Community-associated
 Mild to moderate infections
 Abscess, afebrile, immunocompetent, outpatient
 Cotrimoxazole / doxycycline / minocycline  rifampin
 Clindamycin (do not use if R to erythromycin due to inducible
resistance)
 Abscess with fever, outpatient
 Cotrimoxazole-DS + rifampin or linezolid

41. Methicillin resistant Staphylococcus aureus
(MRSA)
 Clinical guideline for management of suspected
CA-MRSA infections (15 March 2007)
 Most CA-MRSA isolates in HKSAR are susceptible to:
 Cotrimoxazole
 Doxycycline, minocycline
 Clindamycin
 Moxifloxacin
 Out-patient oral therapy available for uncomplicated
CA-MRSA skin and soft tissue infection

42. Methicillin resistant Staphylococcus aureus
(MRSA)
Antimicrobials for outpatient therapy of uncomplicated skin and soft tissue
infections (Clinical guideline for management of suspected CA-MRSA
infections,15 March 2007)
Agent Potential
advantage
Precautions Usual adult dose
(oral)
Cotrimoxazole Oral Not for patient with sulfa
allergy / G6PD
960mg bd
Doxycycline High skin
concentration
Not for children <12 yo
or pregnant women
200mg once, then
100mg bd
Minocycline As above As above 100mg bd
Clindamycin Inhibit toxin
production
Inducible resistance if
erythromycin resistant
300-450mg tds
Moxifloxacin Oral Resistance may
develop during therapy
400mg qd

43. Methicillin resistant Staphylococcus aureus
(MRSA)
 Appropriate treatment in uncomplicated skin and soft
tissue infection
 Cotrimoxazole, doxycycline, minocycline or
moxifloxacin
 Clindamycin is not reliable in this case
 Inducible clindamycin resistance due to erythromycin
resistance

44. Case 2
 What to do if
 the organism is resistant to agents listed above and
vancomycin, and
 Infection is complicated (unstable patient, extensive
involvement, severe sepsis, etc)?

45. VISA and VRSA
 VISA: vancomycin-intermediate Staph aureus
 VRSA: vancomycin-resistant Staph aureus
 Classified based on minimum inhibitory
concentration (MIC)
 (CDC definition)
 VISA: vancomycin MIC is 4-8 µg/ml
 VRSA: vancomycin MIC is >16 µg/ml
 (HA Central Committee on Infectious Diseases)
 Susceptible: vancomycin MIC is ≤ 4µg/ml
 VISA: vancomycin MIC is 8-16 µg/ml
 VRSA: vancomycin MIC is >32 µg/ml

46. Another version of …?

47. Bad Cellulitis

48. MRSA

49. VISA and VRSA
 More likely to develop among patients with
 Underlying conditions (including renal failure) which
predispose the patient to MRSA colonization;
 Indwelling medical devices; and/or
 MRSA infection requiring treatment with vancomycin
for a prolonged period
 Usually isolated during vancomycin (or
teicoplanin) therapy for MRSA infections which
fail to respond

50. VISA and VRSA
 Linezolid (Zyvox®)
 (discussed in PRSP session)
 Quinupristin/dalfopristin (Synercid®)
 Dalbavancin (Zeven®)
 Still under investigation
 Daptomycin (Cubicin®)
 Tigecycline (Tygacil®)

51. Linezolid (Zyvox®)
 Demonstrate bacteriostatic action vs. VISA
and VRSA
 Indications
 Complicated skin and skin structure infections,
including diabetic foot infections, without concomitant
osteomyelitis, caused by MSSA or MRSA, Strep pyogenes,
or Strep agalactiae
 Uncomplicated skin and skin structure infections
caused by MSSA or Strep pyogenes

52. Tigecycline (Tygacil®)
 A glycylcycline
 Derived from minocycline
 A very broad spectrum antibiotic
 Covers many resistant strains of Gram-positive, Gram-
negative, and anaerobic organisms
 Note active vs. Pseudomonas
 Both in vitro and in vivo activities have been
demonstrated against MSSA, MRSA, and VISA

53. Tigecycline (Tygacil®)
 Indications
 Complicated skin and skin
structure infections by
 Escherichia coli
 Enterococcus faecalis
(vancomycin-susceptible
isolates only)
 Staphylococcus aureus
(Methi-S or Methi-R)
 Streptococcus agalactiae
 Streptococcus anginosus grp.
 Streptococcus pyogenes
 Bacteroides fragilis
 Complicated intra-
abdominal infections by
 Citrobacter freundii
 Enterobacter cloacae
 E. coli, K. oxytoca, K.
pneumoniae
 Enterococcus faecalis (Vanco-
S isolates only)
 Staphylococcus aureus
(Methi-S or Methi-R)
 Streptococcus anginosus
group
 Bacteriodes fragilis
 Clostridium perfringens
 Peptostreptococcus micros

54. Gram-negative superbugs
Resistant Gram-negative bacteria terminology
ESBL-producing
Enterobacteriaceae
Extended spectrum beta-lactamases producing
Enterobacteriaceae, e.g. Escherichia coli,
Klebsiella pneumoniae
MRPA (MDR-PA) Multidrug resistant Pseudomonas aeruginosa
MRAB (MDR-AB) Multidrug resistant Acinetobacter baumannii
Pan-resistant Pseudomonas aeruginosa /
Acinetobacter baumannii

55. Case 3
 M/59
 Presented with 2-day history of right upper quadrant pain,
fever, jaundice
 Emesis x 2 past 24 hours, dark color urine
 Elevated LFT
 Radiologic finding: dilated common bile duct, no increase
in gallbladder size
 Diagnosis: acute cholangitis
 Question
 What is the empirical therapy?

56. Acute cholangitis/cholecystitis
 Microbiology
 Gram negative enterics
 E. coli, Klebsiella spp., Proteus spp.
 Anerobes
 Bacteriodes fragilis, Clostridium spp.
 Enterococcus

57. Acute cholangitis/cholecystitis
 Adequate drainage is essential
 Empirical treatment complementary to drainage
 Augmentin/Unasyn ± aminoglycoside
 Timentin
 Cefuroxime + metronidazole
 Ciprofloxacin (if beta-lactam allergic)

58. Case 3
 Biliary drainage performed with cefuroxime +
metronidazole pre- and post-operation
 Became septic (with high fever, tachycardia, WBC
> 12 x 109/L) 2 days post-op
 Blood culture grew E. coli (ESBL-producing),
moderately sensitive to Augmentin, sensitive to
Sulperazon and imipenem
 Question
 What is the appropriate treatment?
 Can Augmentin or Sulperazon be used?

59. Enterobacteriaceae
 Susceptible strains of E. coli and Klebsiella are
sensitive to
 Augmentin/Unasyn
 Cefuroxime (if resistant to above)
 Other anti gram-negative penicillins/cephs also work
 Fluoroquinolones (if allergic to beta-lactams)

60. ESBL-producing Enterobacteriaceae
 Extended-spectrum beta-lactamases
 Any bacterial enzymes that are capable of inactivating
third generation cephalosporins
 Generally regarded as resistant to penicillins and
cephalosporins
 Drug of choice
 Urinary tract infection
 Cotrimoxazole, Augmentin, nitrofurantoin, levofloxacin /
ciprofloxain
 Other serious infections
 Carbapenems: imipenem, meropenem, ertapenem (reliable activity vs.
ESBL-producing Enterobacteriaceae)
 Fluoroquinolone + aminoglycoside

61. Case 3
 Augmentin and Sulperazon are not appropriate
 Patient is clinically septic (likely due to the ESBL-
producing strain of E. coli)
 The strain is only apparently susceptible to the above
agents
 Appropriate agent
 Ertapenem (no activity vs. Pseudomonas)
 Imipenem (when activity vs. Pseudomonas required)

62. Pseudomonas aeruginosa
 Gram-negative bacilli
 Frequently present in small numbers in the
normal intestinal flora and on the skin of humans
and is the major pathogen
 Causes diseases in patients with abnormal host
defenses, e.g.
 When mucous membranes and skin are disrupted
 When intravenous or urinary catheters are used
 When neutropenia is present (as in chemotherapy)
 Intrinsically resistant to many antibiotics

63. Pseudomonas aeruginosa
 Drug of choice
 Antipseudomonal penicillins/cephalosporins
 Piperacillin, piperacillin/tazobactam (Tazocin), ticarcillin/clavulanate
(Timentin)
 Ceftazidime, cefoperazone, cefepime
 Carbapenems
 Imipenem, meropenem (NOT ertapenem)
 Aminoglycosides
 Gentamicin, tobramycin, amikacin
 Fluoroquinolones
 Ciprofloxacin, levofloxacin (less activity than cipro)
 Often a two-drug combination is employed except in
uncomplicated UTI

64. Piperacillin vs. Tazocin
 Tazobactam in Tazocin®
 Tazobactam is a beta-lactamase inhibitor
 Renders the combination of Tazocin® more active
against
 Gram positive: MSSA
 Gram negative: Haemophilus influenzae and others
 Anaerobe: Bacteroides fragilis

65. Piperacillin vs. Tazocin
 Tazobactam in Tazocin®
 For Pseudomonas aeruginosa susceptible to piperacillin,
Tazocin 4.5g Q8H IV and Piperacillin 4g Q8H IV are
equivalent
 At common usual dose (HA Corp drug price as of May
2007)
 Piperacillin 4g/vial: $56
 Tazocin® 4.5g/vial: $108

66. Multidrug resistant
Gram-negative organisms
 Any treatment options for
 ESBL-producing Enterobacteriaceae, or
 Pseudomonas aeruginosa,
that are pan-resistant?

67. Colistin (Colomycin®)
 Indeed an old, toxic drug!
 a.k.a. Polymyxin E, colistimethate sodium
 Now being used with increasing frequency due to necessity
(multidrug resistant Gram-negatives)
 Risk of neurotoxicity and nephrotoxicity
 Spectrum of activity (check susceptibility!)
 Pseudomonas aeruginosa, Acinetobacter spp.
 E. coli and Klebsiella (incl. ESBL-producing strains), Enterobacter
spp.
 Citrobacter spp, Hemophilus spp.
 Indications
 Disease due to Gram-negative bacteria, acute or chronic due to
sensitive strains of certain gram-negative bacilli

68. Acinetobacter baumannii
 Common cause of nosocomial infection especially
in ICU setting
 Drug of choice
 Ampicillin/sulbactam or cefoperazone/sulbactam
(sulbactam highly active vs. Acinetobacter) or
fluoroquinolone (ciprofloxacin, levofloxacin)
 Gentamicin added to prevent resistance and for synergy
 Imipenem, meropenem can be used

69. Acinetobacter baumannii
 Acinetobacter strains are often resistant to
antimicrobial agents
 Other agents with in vitro activity vs. Acinetobacter
baumannii
 Minocycline / doxycycline
 Tigecycline
 Colistin

70. Sinusitis: X-rays
Streptococcus Pneumonia
Hemophillus Influenza
Morexalla Catarrhalis

71. Sinusitis: Treatment
 Mild Acute Bacterial Sinusitis (ABS)
 Amoxicillin
 Amoxicillin/clavulanate
 Cefuroxime axetil
 Cefpodoxime
 Or antistrep. fluoroquinolones:
 Levofloxacin
 Moxifloxacin

72. Sinusitis: Treatment
 Drug option in the case of allergies to penicillin and
cephalosporin with Mild ABS:
 Doxycycline
 Trimethoprim/sulfamethoxizole
 Azithromycin
 Clarithromycin

73. Sinusitis: Treatment
 Drug option in the case of allergies to penicillin and
cephalosporin with Moderate to Severe ABS:
 Antipneumococcal fluoroquinolone:
 Levofloxacin
 Moxifloxacin

74. Intra-abdominal infections
 Common bacterial organisms
 GNRs
 E. coli, Klebsiella, Proteus
 Enterococcus and anaerobes also common

75. Intra-abdominal infections
 Empiric therapy should cover GNRs and anaerobes
(Bacteroides fragilis)
 Ampicillin/sulbactam
 Ticarcillin/clavulanate
 Piperacillin/tazobactam
 Carbepenem: imipenem, meropenem

76. Intra-abdominal infections
 Cefoxitin no longer has reliable coverage against B.
fragilis
 Cefotetan, another second generation
cephalosporin, might be back on the market soon
 Pts allergic to penicillin could use:
 Fluoroquinolone + metronidazole
 For severely ill, cover Pseudomonas

78. Pregnancy
 Avoid tetracycline class
 Staining of teeth and bones in babies
 Avoid sulfa drugs in the third trimester
 May be associated with kernicterus
 Avoid aminoglycosides
 Kidney toxicities
 Fluoroquinolones – class C
 Concerns about cartilage development

79. Pregnancy
 Treat the Mother first and the baby will appreciate it 
 Penicillins and cephalosporins are generally safe in
pregnancy.
 Macrolides are generally safe
 They may increase nausea early on

80. Meningitis: Treatment
 Adults and children>2 months old:
 High dose ceftriaxone or cefotaxime
+
 Vancomycin
 Ampicillin can be added if Listeria monocytogenes is a
consideration

81. Meningitis: Use of steroids
 Give dexamethasone before or with the first dose of
antibiotics.
 Corticosteroid treatment has been shown to decrease
neurologic complications in children and is now
recommended in adults.
 Continue steroids every 6 hours for four days.

82. Antibiotic Stewardship Program in
Hospital Authority
 Multidisciplinary, programmatic, prospective,
interventional approach to optimizing the use of
antimicrobial agents
 The multidisciplinary team typically includes
 Clinical microbiologists
 Infectious diseases specialists
 Clinical pharmacists
 Infection control practitioners

83. Antibiotic Stewardship Program
 Involves
 Prescribing antimicrobial therapy only when it is
beneficial to the patient
 Targeting therapy to the desired pathogens
 Using the appropriate drug, dose, and duration

84. Antibiotic Stewardship Program
 Should not be viewed simply as reduced use or a
strategy for cost containment
 A strategy to enhance patient safety by
 Minimizing exposure to drugs
 Performing dose adjustments
 Reducing redundant therapy
 Targeting therapy to the likely pathogens

85. Big gun audit
 Big gun audit
 Targets 2 types of antibiotics
 Broad-spectrum antibiotics
 Tienam, Meropenem, Ceftazidime, Cefepime, Tazocin,
Sulperazon
 All these agents have good Gram-negative as well as
Pseudomonas coverage
 Anti Gram-positive antibiotics
 Vancomycin and teicoplanin
 Active vs. methicillin-resistant Staphylococcus aureus
 To be used as second-line agents

86. IV-PO switch
 IV-PO switch
 Criteria (as per IMPACT)
 1. No indication for IV therapy
 2. Patient is afebrile for ≥ 8 hours
 3. WBC count is normalizing
 Falling towards or < 10 x 109/L
 4. Signs and symptoms related to infection are improving
 5. Patient is not neutropenic
 Neutrophil count > 2 x 109/L

87. IV-PO switch
 IV-PO switch
 Criteria (as per IMPACT)
 6. Able to take drugs by mouth (non-NPO)
 7. No continuous nasogastric suctioning
 8. No severe nausea or vomiting, diarrhea, gastrointestinal
obstruction, motility disorder
 9. No malabsorption syndrome
 E.g. small bowel syndrome due to resection
 10. No pancreatitis or active gastrointestinal bleeding or other
conditions that contraindicated to the use of oral medications

88. IV-PO switch
 IV-PO switch
 Points to note
 Prescribe dose based on creatinine clearance when
antimicrobials require renal dosage adjustment
 Augmentin®, Unasyn®, clarithromycin, ciprofloxacin,
levofloxacin
 Drug interactions
 Oral ciprofloxacin and levofloxacin with antacid, sucralfate,
didanosine, dairy products and enteral feeds

89. Reducing bacterial resistance
 IMPACT (Interhospital Multi-disciplinary
Programme on Antimicrobial ChemoTherapy)
 Available for download at:
 HKU Centre of Infection
http://www.hku.hk/hkucoi/impact.pdf
 DH Centre for Health Protection
http://www.chp.gov.hk/files/pdf/reducing_bacterial_resistance_
with_impact.pdf
 HA intranet
http://ha.home/ho/ps/impact.pdf
 Most updated: third version 2005 (version 3.0)

90. IMPACT guideline
 Contents of IMPACT guideline
 Local antibiotic resistance
 Guidelines for selected antimicrobial use, e.g.
 Vancomycin
 Ceftazidime
 Imipenem/meropenem/ertapenem
 Once daily aminoglycosides
 Selected antifungal agents

91. Useful guides to antimicrobial therapy
 Sanford Guide
 Covers a broad range of infectious diseases
 IMPACT
 With commonly prescribed empirical therapy and
useful local resistance information
 Local antibiogram
 Bacterial resistance specific to an institution or a cluster
of institutions

92. Conclusion
 New antibiotics intended to treat complicated
diseases are under investigation
 Need to protect our antibiotic arsenal
 Justified use of antimicrobials not only treats
infections, but also improves patient outcomes and
reduces the risk of development of bacterial
resistance
 Adherence to clinical guidelines, antimicrobial
stewardship program and education helps to
promote appropriate antimicrobial use

93. Conclusion
 Last but not least…
 Infection control is of utmost importance in reducing
risk of infection, use of antibiotics and hence emergence
of bacterial resistance
 Hand hygiene
 Appropriate isolation / contact restriction
 Prompt reporting of certain infectious diseases (e.g. MRSA
infections)
 Many more!

94. Thank You