APPENDIX 3: Empiric Regimens for Common Infections

Infection

Common

Patient/Infection Factors

Initial Empiric Therapy

Pathogens

Options

Community-

Streptococcus

Outpatient, otherwise healthy,

Doxycycline or Azithromycin

acquired

pneumoniae

no recent antibiotic exposure

or Clarithromycin

pneumonia

Haemophilus

influenzae

Mycoplasma

pneumoniae

Chlamydophila

pneumoniae

Legionella

pneumophila

Outpatient, comorbidities

Amoxicillin or

and/or recent antibiotic

Amoxicillin/Clavulanate

exposure

or

Cefuroxime

-Plus-

Azithromycin or

Clarithromycin

-OR-

Levofloxacin or Moxifloxacin

or Gemifloxacin

Inpatient, non-ICU

Ceftriaxone or Cefotaxime or

Ampicillin or Ertapenem

-Plus-

Azithromycin or

Clarithromycin or Doxycycline

-OR-

Levofloxacin or Moxifloxacin

Inpatient, ICU

Ceftriaxone or Cefotaxime or

Ampicillin/Sulbactam

-Plus-

Azithromycin or Levofloxacin

or Moxifloxacin

Healthcare-

Streptococcus

Early-onset (within 5 days of

Ceftriaxone or

associated

pneumoniae

hospitalization) and no recent

Ampicillin/Sulbactam or

pneumonia

Haemophilus

antibiotic exposure

Ertapenem or Levofloxacin or

influenzae

Moxifloxacin

Staphylococcus

aureus (MSSA)

Escherichia coli

Klebsiella

pnueumoniae

As above plus:

Late-onset (after 5 days of

Cefepime or Ceftazidime or

Staphylococcus

hospitalization) and/or recent

Imipenem or Meropenem or

aureus (MRSA)

antibiotic exposure

Piperacillin/Tazobactam or

Enterobacter

Aztreonam

species

-Plus-

Proteus

Ciprofloxacin or Levofloxacin

species

or Gentamicin or Tobramycin

Serratia

or Amikacin

species

-Plus-

Pseudomonas

Vancomycin or Linezolid

aeruginosa

Otitis media

Viruses

Mild-moderate otalgia with

Amoxicillin or Cefuroxime or

Streptococcus

temperature ≤ 39°C

Cefpodoxime or Azithromycin

pneumoniae

Haemophilus

influenzae

Moraxaella

catarrhalis

Severe otalgia and/or

Amoxicillin/Clavulanate or

temperature ≥ 39°C

Ceftriaxone

Pharyngitis

Viruses

Documented or high risk for

Penicillin VK or Cephalexin or

Streptococcus

Streptococcus pyogenes

Azithromycin

pyogenes

Urinary tract

Escherichia coli

Uncomplicated community-

TMP/SMX or Nitrofurantoin or

infections

Proteus

acquired lower urinary tract

Fosfomycin or

species

infection in healthy women, <

Ciprofloxacin or Levofloxacin

Klebsiella

50 years old

pneumoniae

Staphylococcus

saphrophyticus

Enterococcus

species

Community-acquired

Ciprofloxacin or Levofloxacin

complicated urinary tract

or Ceftriaxone or Ertapenem

infection or pyelonephritis

As above plus:

Nosocomial complicated

Ceftazidime or

Enterobacter

urinary tract infection or

Piperacillin/Tazobactam or

species

pyelonephritis

Cefepime or Meropenem or

Pseudomonas

Imipenem

aeruginosa

Skin/soft

Streptococcus

Low risk for MRSA

Cefazolin or Nafcillin or

tissue

pyogenes

Cephalexin or Dicloxacillin

infections

Staphylococcus

aureus

High risk for MRSA

Vancomycin or Linezolid or

Clindamycin

-OR-

Cephalexin or Dicloxacillin

-Plus-

Doxycycline or TMP/SMX

As above plus:

Diabetic foot infection,

Ceftriaxone or

Escherichia coli

moderate to severe

Ampicillin/Sulbactam or

Proteus

Piperacillin/Tazobactam or

species

Ertapenem

Klebsiella

-OR-

pneumoniae

Levofloxacin or Ciprofloxacin

Bacteroides

-Plus-

fragilis

Clindamycin

Enterococcus

All WITH or WITHOUT

species

Vancomycin

Pseudomonas

aeruginosa

Intra-

Escherichia coli

Community-acquired, mild-

Ertapenem or Moxifloxacin or

abdominal

Proteus

moderate severity

Tigecycline

infections

species

-OR-

Klebsiella

Cefazolin or Ceftriaxone or

pneumoniae

Levofloxacin or Ciprofloxacin

Bacteroides

-Plus-

fragilis

Metronidazole

Enterococcus

species

viridans

Streptococcus

As above plus:

Community-acquired, high

Piperacillin/Tazobactam or

Pseudomonas

severity or high-risk patient

Imipenem or Meropenem

aeruginosa

-OR-

-OR-

Enterobacter

Nosocomial (any severity or

Ceftazidime or Cefepime

spp

patient)

-Plus-

Serratia spp

Metronidazole

All WITH or WITHOUT

Vancomycin

Community-

Streptococcus

Otherwise healthy, 2–50 years

Ceftriaxone

acquired

pneumoniae

of age

-Plus-

meningitis

Neisseria

Vancomycin

meningitidis

As above plus:

> 50 years of age or

Ceftriaxone

Listeria

immunocompromised

-Plus-

monocytogenes

Vancomycin

-Plus-

Ampicillin

Healthcare-

Clostridium

Mild-moderate infection

Metronidazole (oral)

associated

difficile

infectious

diarrhea

Severe infection

Vancomycin (oral) or

Fidaxomicin

Severe, complicated infection

Vancomycin (oral)

(e.g., ileus)

-Plus-

Intravenous metronidazole

Community-

Shigella

See above

Fluoroquinolone or TMP/SMX

acquired

Salmonella

if antibiotic therapy is

infectious

Escherichia coli

necessary