| |
Drug of choice |
Alternatives |
Remarks |
| Acinetobacter baumannii |
I.V. ampicillin-sulbactam + an aminoglycoside |
- I.V. cefoperazone-sulbactam + an aminoglycoside (mixed infection with P. aeruginosa)
- Fluoroquinolone + an aminoglycoside (if allergic to penicillin)
|
- Sulbactam is highly active against Acinetobacter
- Resistance rates in 2010: ampicillin-sulbactam (24%), cefoperazone-sulbactam (24%), imipenem (37%), gentamicin (32%), amikacin (25%), ciprofloxacin (50%)
- For multidrug-resistant isolates: consult microbiologist or infectious disease physician
|
| Clostridium difficile |
P.O. metronidazole (404–405) |
P.O. vancomycin (if metronidazole fails as
documented microbiologically) |
- Mild/moderate disease: clinical efficacy of metronidazole = vancomycin
- Severe disease, ileus or toxic megacolon: I.V. metronidazole + P.O. vancomycin + consult surgeon
- First recurrence: same as primary infection based on severity of disease
- Multiple recurrence: consult microbiologist or infectious disease physician, options include vancomycin taper or faecal microbiota transplant (406)
|
| Enterobacter cloacae complex |
- P.O./I.V. levofloxacin/ ciprofloxacin for urinary tract infection
- I.V. cefepime (± an aminoglycoside)
for severe infection
- I.V. piperacillin-tazobactam
|
- I.V. carbapenem (for severe
infection and/or ESBL-producing strain)
|
- Cefepime is highly active in vitro against almost all Enterobacter isolates
- Emergence of AmpC derepressed
mutants emerge in 20–40% of
infections treated with the second
or third generation
cephalosporins. Use of these
agents for serious infections is
not recommended
- One study in HK found high
prevalence of ESBL production
among E. hormaechei (a member
of the E. cloacae complex) (407)
- Resistance rate in 2010:
levofloxacin (8%), gentamicin
(4%), amikacin (1%)
- For multidrug-resistant isolates:
consult microbiologist or
infectious disease physician
|
| E. coli (ESBL-neg) |
- I.V./P.O. ampicillin-sulbactam or
amoxicillin-clavulanate (add an aminoglycoside if rapid Bactericidal action desirable on clinical grounds)
|
- I.V./P.O. cefuroxime (if resistant to amoxicillin-clavulanate), add I.V./P.O.
metronidazole (if mixed infection with anaerobes likely)
- I.V. piperacillin-tazobactam + an aminoglycoside (if P. aeruginosa or Acinetobacter are co-pathogens)
|
|
| Haemophilus influenzae |
- P.O. amoxicillin or P.O./I.V. ampicillin-sulbactam or amoxicillin-clavulanate or cefotaxime or ceftriaxone
|
- Fluoroquinolones (if allergic to penicillin)
|
- Amoxicillin-clavulanate also
provides good coverage for M.
catarrhalis and S. pneumoniae
|
| Klebsiella pneumoniae (ESBL-neg) |
- I.V./P.O. ampicillin-sulbactam
or amoxicillin-clavulanate (add an aminoglycoside if rapid bactericidal action desirable on clinical grounds)
|
- I.V./P.O. cefuroxime (if resistant to amoxicillin-clavulanate), add I.V./P.O. metronidazole (if mixed infection with anaerobes likely)
- I.V. piperacillin-tazobactam + an aminoglycoside (if P. aeruginosa or Acinetobacter are co-pathogens)
|
- Ampicillin-sulbactam less
satisfactory because of poor
inhibitory activity of sulbactam
for SHV-1 ß-lactamase
|
| E. coli / K. pneumoniae (ESBL-pos) |
- P.O. nitrofurantoin or P.O. amoxicillin-clavulanate (uncomplicated urinary tract infection and other mild infections)
|
- Carbapenem or I.V. β-lactam/β-lactamase inhibitor for bacteraemia or other serious infection
|
- Carbapenem has been shown to be effective clinically and is currently the ß-lactam agent of choice for serious infection by ESBL-pos E. coli / Klebsiella spp.
|
| Pseudomonas aeruginosa |
I.V. piperacillin or ticarcillin-clavulanate or piperacillin-tazobactam + an aminoglycoside |
- I.V. cefoperazone-sulbactam
+ an aminoglycoside (mixed
infection with Acinetobacter)
- I.V./P.O. levofloxacin/ ciprofloxacin + an aminoglycoside (if allergic to penicillin)
|
- Combination therapy recommended (for synergism) for all serious infection except for uncomplicated catheter-related bacteraemia
- Piperacillin-tazobactam used instead of ceftazidime due to rapid rise in AmpC type and ESBL-producers in Enterobacteriaceae
- For multidrug-resistant isolates: consult microbiologist or infectious disease physician
|
| Methicillin-sensitive S. aureus |
P.O./I.V. cloxacillin or amoxicillin-clavulanate or ampicillin-sulbactam or first generation cephalosporin |
- I.V. cefazolin (if allergic to penicillin, but limited to those with minor allergy such as rash alone)
- Clindamycin (if allergic to penicillin)
|
|
| Methicillin-resistant S. aureus |
I.V. vancomycin (bacteraemia or other invasive infections) |
- I.V./P.O. linezolid or I.V. daptomycin if (1) vancomycin allergy - extensive rash, other than red-man syndrome
develop after vancomycin, or (2) bacteraemia caused by MRSA with vancomycin ≥ 2 μg/mL
|
- Cotrimoxazole, fusidic acid or rifampicin are useful adjuncts for deep-seated infections (e.g. osteomyelitis) but these agents should not be administered as monotherapy
- Most abscesses or uncomplicated skin and soft tissue infection caused by CA-MRSA could be treated with drainage and oral antibiotics with in vitro activities (e.g. clindamycin or cotrimoxazole)
- Vancomycin intermediate Staphylococcus aureus / vancomycin resistant Staphylococcus aureus: consult microbiologist or infectious disease physician
|
| Mycoplasma pneumoniae |
- P.O. doxycycline (or I.V. minocycline)
|
- P.O. azithromycin
- I.V./P.O. levofloxacin or moxifloxacin
|
- Doxycycline preferred over azithromycin in view of increasing macrolide resistant Mycoplasma pneumoniae (379)
|
| Stenotrophomonas maltophilia |
P.O./I.V. cotrimoxazole + I.V. ticarcillin-clavulanate |
- I.V./P.O. cotrimoxazole + fluoroquinolone
|
- Cotrimoxazole + ticarcillin-clavulanate is synergistic in vitro. Cotrimoxazole is a key component in therapy
- Combination therapy recommended for synergy and to prevent resistance
- For cotrimoxazole-resistant strain, consult microbiologist or infectious disease physician
|
Streptococcus pneumoniae
(for infection outside the central nervous system) |
- Penicillin-sensitive: I.V. penicillin G (4–8 million unit/day, q6h)
- Penicillin-intermediate: I.V. penicillin G (high dose, 12–18 million unit/day, q4h)1
- Penicillin-resistant: I.V. cefotaxime or ceftriaxone
|
- ß-lactam/ß-lactamase inhibitor combination with the exception of cefoperazone-sulbactam (for mixed infections)
- P.O./I.V. levofloxacin or P.O./I.V. moxifloxacin (if allergic to penicillin) for non-meningeal infections and penicillin-sensitive strains
|
- Most pneumococcal pneumonia can be treated with high dose amoxicillin or high dose amoxicillin-clavulanate
- For pure pneumococcal infection, penicillin G instead of amoxicillin-clavulanate is preferred, switch therefore recommended
- >70% resistant to erythromycin. Cross-resistance to clindamycin is very common
- Resistance to erythromycin = resistance to other newer macrolides (clarithromycin, azithromycin)
|
Streptococcus pneumoniae
(for central nervous system infection) |
- Penicillin-sensitive (MIC ≤ 0.06 μg/mL): I.V. penicillin G (18–24 million unit/day, q4h) or I.V. ampicillin 2 g q4h
- Penicillin-resistant (MIC ≥ 0.12 μg/mL) and third-generation cephalosporin (MIC <1 μg/mL): I.V. cefotaxime 2 g q4h or I.V. ceftriaxone 2 g q12h
- Penicillin-resistant (MIC ≥ 0.12 μg/mL) and third-generation cephalosporin (MIC ≥ 1 μg/mL): I.V. vancomycin plus I.V. cefotaxime 2 g q4h or ceftriaxone 2 g q12h
|
|
- MIC (meningitis) breakpoints for penicillin, ceftriaxone and cefotaxime to be used here
- In S. pneumoniae, cross resistance between penicillin and ceftriaxone / cefotaxime is common (391,408). Local data indicates that approximately half of the penicillin-resistant (meningitis) isolates are intermediate / resistant (meningitis) to cefotaxime
|
