Monday, May 7, 2012

Empirical antibiotics treatment

compiled for the purpose of preparation for the USMLE step 2

Bacterial Meningitis: Ceftriaxone+vancomycin+steroids+/- Ampicillin

Though no culture results yet, you would have done LP (xcept if contraindicated) so u have an idea if bacterial (wbc in thousands)
If immunosuppressed or neonate or elderly or alcoholic and gram stain yields nothing , add Ampicillin (for Listeria monocytogenes which r gram positive rods). However, if gram stain already shows gram positive cocci, Ampicillin will be unneccessary.
Don't use ceftriaxone in neonates, use cefotaxime
Steroids lower mortality in pneumococcal meningitis
If confirmed Neisseria meningitis, give Rifampicin or ciprofloxacin to close contacts, isolate patient.
If culture results yield susceptible pneumococci, stop vancomycin.

Otitis Media: Amoxicillin

Sinusitis: Amoxicillin (or trim/sulfa or doxycycline) + decongestant

Pharyngitis: Amoxicillin
Rapid strep test done in the office diagnoses strep pharyngitis within minutes so the tmt is not really 'empirical' so to speak
(for penicillin allergic pt: clindamycin or clarithromycin Or if allergy is only a rash, use cephalexin)

Severe infectious diarrhoea: Ciprofloxacin + fluids
Severe if: hypotension, fever, bloody diarrhoea, abdo pain or acidosis -in this scenario, suspect bacterial etiology

if mild infectious diarrhoea, give fluids only

Urethritis: Ceftriaxone (or cefixime)  + doxycycline (or Azithromycin)

PID: exclude pregnancy first and give Ceftriaxone+doxycycline (outpatient)
or if inpatient, cefotetan + doxycycline

If pregnant, substitute doxycycline with azithromycin or amoxycillin or erythromycin

UTI: ciprofloxacin
or Trim/sulfa or cephalexin in cystitis
(Nitrofurantoin in pregnancy)
or Ampicillin+gentamicin for Pyelonephritis
(with PyNeph, suspect abscess if persistent fever after 5-7 days of antibiotics, do Sonography or CT and drain)

Acute Prostatitis: Ampicillin+gentamicin
(Chronic prostatitis:Trim/sulfa *8wks)

Endocarditis: Vancomycin + gentamicin

Community acquired pneumonia:
As outpatient:
Azithro or Clarithromycin or doxycycline  (if existing comorbidities/previous antibiotics, give Levofloxacin)
As inpatient:
Levo or moxifloxacin or Ceftriaxone+azithromycin

Hospital acquired pneumonia (after >48hrs in hospital):

Lung abscess: Clindamycin or Penicillin
usually due to aspiration thus cover for anaerobes

Impetigo: (staph and strep)
mild-    Topical mupirocin or bacitracin or Repatamulin
severe- Oral doxycycline or clindamycin or Trim/sulfa

(some say topical alone is not enough!)

Erysipelas: (strep > staph),Cellulitis: (staph>strep)
mild:    oral dicloxacillin or cephalexin or if allergic, macrolide or clindamycin
severe: iv oxacillin or nafcillin or cefazolin or if allergic, clindamycin

Postpartum Endometritis:
Clindamycin + gentamicin

Spontaneous bacterial peritonitis:  Cefotaxime

edited 8/06/12