TOC  |  Infectious Diseases Empirical Antibiotic Therapy    Revised  September 2004  (KP Bellflower ID Department)
Outpatient Empiric Therapy Guidelines - ADULTS


Common Pathogens


Alternate Drugs

Acute Bronchitis Usually viral No antibiotics indicated
Acute Bacterial exacerbation of chronic bronchitis

S.pneum; H.flu; M.catarrhalis; Mycoplasma pneum; Chlamydia pneum. Amoxicillin 1000 mg bid x 5 days Septra-DX BID
Doxycycline 100 mg BID
Erythromycin 500 mg QID x 5 days
Cefuroxime 500 mg bid
Augmentin 875 mg BID for Moraxella or Hemophilus

* Azithromycin 500 mg x1, then 250 mg/d x 4 days. (If severe GI intolerance to erythromycin)

Pneumonia - Outpatient Community Acquired Pneumonia - CAP  (1) Cefpodoxime 200mg po BID plus Doxycycline 100mg po BID x10days   OR  
Azithromycin 500mg po qd x 5-7days
PCN R – Moxifloxacin 400mg po daily
Pneumonia - Inpatient CAP IV Cefotaxime 1gm q8h + IV or po Erythro 500mg q6h or IV/po Doxycycline 100mg q12h if Erythro not available. IV Moxifloxacin 400mg daily +/- Clinda
Cellulitis - Uncomplicated or Diabetic  (2) Clindamycin 900mg IV q8h +/- Cefazolin 1 gram IV q8h If allergiic to Clinda, use Linezolid 600mg IV q12h. If allergic to Cefazolin, just use Clinda alone.

Diabetic/Ischemic foot infections with
Amputation risk (3)

Ceftazidime 1gm q8h + Clinda ± Gentamicin (for Cre > 1.5, don’t use SDDA) or

Unasyn 3gms q6h ± Gentamicin (for Cre > 1.5, don’t use SDDA)

Cipro 500 or 750mg po q 12h or 400mg IV q 12h if can’t take po + Clinda
Pyelonephritis  (4)

Gentamicin SDDA + Ampicillin 1-2gms q6h Can switch to po TMS (or Cipro if resistant; can also use Keflex) as soon as medically improved and can tolerate po Ceftazidime 1 gm q 8h - discharge on TMS if sensitive or Cipro if R to TMS; can also use Keflex 500mg QID
Appendicitis  (5) Amp 2gms q6h, Flagyl 500mg q8h, Gent SDDA Clinda + Gentamicin SDDA

Clinda + Ceftazidime 1gm q8h

Clinda + Cipro 400mg IV q12h

Cholecystitis Piperacillin 3gms q6h + Gent SDDA

Amp 2gms q6h, Flagyl 500mg q8h, Gent SDDA

Clinda + Gentamicin SDDA

Clinda + Ceftazidime 1gm q8h

Clinda + Cipro 400mg IV q12h

Peritonitis Amp 2gms q6h, Flagyl 500mg q8h, Gent SDDA Clinda + Gentamicin SDDA

Clinda + Ceftazidime 1gm q8h

Clinda + Cipro 400mg IV q12h

Meningitis age 18-50 (6)

Age >50 (add Listeria)

Impaired cellular immunity (add GNR)

Head trauma, neurosurg, CNS shunt

If see GPC on gram stain of CSF

Cefotaxime 2gms q6-8h

Amp 3gms q4-6h + Cefotaxime

Amp + Cefotaxime 2gms q8h + Vanco

Vanco 1gm q12h + Ceftazidime

Vanco + Cefotaxime 2gms q6h

Meropenem 1gm q8h + Vancomycin
Neutropenic Fever Ceftazidime alone 1gm q8h

Ceftazidime ± Gentamicin

Meropenem 1gm q8h
Sepsis of Unknown Source (7) Vanco 1 gm q8h + Clinda 900mg q8h + Gent SDDA (or Ceftazidime 1 gm q8h if Cr>2.0) Vanco alone 1gm q12h if allergic to Clinda

Cipro 400mg IV q12h if allergic to Ceftazidime

Revised  September 2004  (KP Bellflower ID Department)

Notes and Commentaries:

  1. Note that Azithromycin alone is sufficient as an alternative to the combination of Cefpodoxime/Doxy). Patients from nursing homes can generally be treated in the same fashion, ie, they don’t have to be considered the same as hospital acquired pneumonia.
  2. The mere fact that a patient is diabetic does not indicate a need for anaerobic coverage. This is reserved for more complex ischemic foot infections with amputation risk. However, Clinda has become the drug of first choice b/o the rising incidence of community associated MRSA (CAMRSA) which is often sensitive to Clindamycin..
  3. Gentamicin can be used in single daily dosing regimens except when it is used for synergy. This is why you see the note to not use SDDA. Also, consistent with our desires to limit Cipro use, Cipro should definitely be the third option for this condition and additionally can be considered for po use since blood levels are almost the same po and iv.
  4. Again, consistent with our desires to limit Cipro (and by extension, quinolone) use, TMS is always preferred if the organism is sensitive and the patient is not allergic. Can also consider using Keflex although it does not have the advantage of eliminating periurethral colonization like TMS and Cipro do. In addition, the patient can generally be switched to po therapy once they are able to tolerate po drugs and they are hemodynamically stable, even if they were bacteremic. Lastly, also note that there is no indication for the combination of Cipro/Ceftazidime. Use either one or the other but not both.
  5. Note that Clinda is preferred as the anaerobic agent in regimens where there will be poor gram positive coverage such as with Gent or Cipro
  6. The initial approach to meningitis first of all assumes that the presentation is consistent with a bacterial infection since most cases of meningitis are aseptic. Secondly, antibiotic coverage varies depending on various factors as listed, eg, if the patient is >50, add Ampicillin b/o the risk of Listeria. A gram stain of CSF should always be sent stat and if gpc are noted, add Vanco for possible resistant Strep pneumo. No cases of PCN resistant Step pneumo meningitis have been seen at BF to date but this is simply a precaution.
  7. Remember that this refers ONLY to patients who literally do not have an identifiable source. Those w/abd pain or dysuria or back pain or cellulitis HAVE a potential source and they fall into a different category.