Infetious disease ABXTX 1 Flashcards
Community-Acquired Pneumonia (CAP)
- Ceftriaxone 1 g IV qday + Azithromycin 500 mg, then 250 mg PO/IV qday
- Moxifloxacin 400 mg PO/IV or Levofloxacin 750 mg PO/IV qday.
* For severely ill patients, consider addition of Vancomycin or Linezolid for coverage of community-acquired MRSA.
* Consider anti-Pseudomonal coverage if risk factors present.
Hospital, Healthcare- Associated, or Ventilator-Associated Pneumonia
(HAP, HCAP, VAP)
- Anti-MRSA antibiotic: Vancomycin 15-20 mg/kg IV q12 hrs or Linezolid 600 mg PO/IV bid
+ - Antipseudomonal Beta-Lactam: Ceftazidime 2 g IV q8 hrs, Cefepime 2 g IV q8 hrs, Piperacillin/Tazobactam 4.5 g IV q6 hrs, Imipenem 500 mg IV q6 hrs or Meropenem 1-2 g IV q8 hrs; Aztreonam 1-2 g IV q8 hrs if severe penicillin allergy.
*For severely ill patients, or if high risk of resistant gram negative infection, also consider addition of “double coverage” with Antipseudomonal Fluoroquinolone (Ciprofloxacin or Levofloxacin), or Aminoglycoside.
Aspiration Pneumonia
- Levofloxacin 750 mg PO/IV q24 hrs + Metronidazole 500 mg PO/IV q8 hrs, or
- Clindamycin 600 mg IV q8 hrs (add Levofloxacin if concern for community-acquired pneumonia), or
- Ampicillin/Sulbactam 3 g IV q6 hrs
* If nosocomial – treat as HAP, with preference for Piperacillin/Tazobactam, Imipenem or Meropenem for anaerobic coverage, or add Clindamycin or Metronidazole.
Appendicitis, Diverticulitis, Intraabdominal Abscess, Secondary Peritonitis
- Ceftriaxone 1 g IV qday + Metronidazole 500 mg IV q8hrs, or
- Ciprofloxacin 400 mg IV q12 hrs or Levofloxacin 500 mg IV 24 hrs + Metronidazole (caution with Cipro due to poor strep coverage), or
- Piperacillin/Tazobactam 3.375 g IV q6 hrs, or
- Imipenem 500 mg IV q6 hrs or Meropenem 1 g IV q8 hrs.
* For severely ill or healthcare/hospital-acquired disease, consider addition of Enterococcal and Candida coverage (especially if not responding to therapy).
* Caution with Ampicillin/Sulbactam alone due to high rates of E.coli resistance at some institutions.
Spontaneous Bacterial Peritonitis (SBP) in patients with ascites
Cefotaxime 2 g IV q8 hrs or Ceftriaxone 1 g IV q 24 hrs
+ Albumin 1.5 g/kg on day 1 and 1 g/kg on day 3
Cholangitis
Ceftriaxone 1 g IV qday, Ciprofloxacin 400 mg IV bid, or Levofloxacin 500 mg IV qday
+ Metronidazole 500 mg IV q8 hrs if biliary-enteric anastomosis.
If severe or healthcare-associated infection, consider Piperacillin/Tazobactam or Imipenem or Meropenem.
Acute cystitis
- Bactrim DS 1 tb po bid x 3 days, or
- Nitrofurantoin 100 mg po bid x 5 days (contraindicated in renal failure), or
- Fosfomycin 3 g po x 1 dose
* Avoid Nitrofurantoin and Fosfomycin if pyelonephritis is a possibility (do not penetrate kidney tissue).
* Ciprofloxacin is 2nd-line due to high rates of resistance (and should be reserved for other purposes).
Acute pyelonephritis
- Ceftriaxone 1 g IV q24 hrs, or
- Ciprofloxacin 400 mg IV q12 hrs or Levofloxacin 500 mg IV q24 hrs (2nd-line due to resistance), or
- Cefepime 1 g IV q12 hrs (especially if prior resistant organisms or Pseudomonas)
Complicated UTI (defined by presence of anatomic or functional abnormality in GU tract, or urinary catheter)
- If mildly ill – Ciprofloxacin 400 mg IV q12 hrs or Levofloxacin 500 mg IV q24 hrs or Ceftriaxone 1 g IV q24 hrs.
- If severely ill - Cefepime 1 g IV q12 hrs, or Ceftazidime 1 g IV q8 hrs, or carbapenem if high risk for ESBL, or history of prior infections. Consider adding Vancomycin especially if history of prior infection, chronic urinary catheters or stents.
Cellulitis
- Oral options: Cephalexin 500 mg po q6 hours, Clindamycin, Dicloxacillin.
Add MRSA coverage if purulent or severe disease. Oral options include Bactrim 2 DS tabs bid (best) or Doxycycline 100 mg po bid (both have poor strep coverage so should be paired with one of the oral beta-lactams). Clindamycin is an option but CA-MRSA resistance can exceed 50%. - IV options for Strep, low suspicion for MRSA: Cefazolin 1 g IV q8 hrs, Clindamycin 600 mg IV q8 hrs.
- IV options with MRSA coverage: Vancomycin 15-20 mg/kg IV q12 hrs, Linezolid 600 mg PO/IV q12 hrs, Daptomycin 4-6 mg/kg IV q24 hrs, Clindamycin 600 mg IV q8 hrs (but MRSA often resistant)
Infected Diabetic Foot Ulcer
- Moderate disease - Ceftriaxone 1 g IV qday, Levofloxacin 750 mg po/IV qday, or Cefepime 1 g IV q8 hrs, all with Metronidazole 500 mg po/IV q8 hrs.
- Severe disease: Vancomycin 15-20 mg/kg IV q12 hrs, and anti-Pseudomonal beta-lactam (Ceftazidime 2 g IV q8 hrs, Cefepime 2 g IV q8 hrs, or Aztreonam 2 g IV q8 hrs with Metronidazole 500 mg q8 hrs, or Piperacillin/Tazobactam 4.5 g IV q6 hrs or Imipenem 500 mg IV q6 hrs or Meropenem 1 g IV q8 hrs).
Necrotizing Fasciitis
In addition to emergent surgical debridement:
1. Anti-MRSA agent: Vancomycin 15-20 mg/kg IV q12 hrs, consider loading dose of 25-30 mg/kg, or Linezolid 600 mg IV q6 hrs, or Daptomycin 6 mg/kg IV q24 hrs
+
2. Broad spectrum beta-lactam:
Piperacillin/Tazobactam 4.5 g IV q6 hrs, Imipenem 500 mg IV q6 hrs, Meropenem 1 g IV q8 hrs alone,
or Cefepime 2 g IV q8 hrs + Metronidazole 500 mg IV q8 hrs.
* Consider addition of Clindamycin 600-900 mg IV q8 hrs for antitoxin effect vs Strep and Staph. IVIG may be beneficial in cases due to Group A Strep.
Bacterial Meningitis, Community-Acquired
Ceftriaxone 2 g IV q12 hours + Vancomycin 15-20 mg/kg IV q8 hrs (target trough ~20 mcg/mL).
- Add Ampicillin 2 g IV q4 hours if at risk for Listeria.
- If severe beta-lactam allergies: Vancomycin + Moxifloxacin or Chloramphenicol (+ Bactrim if risk for Listeria).
- Consider Dexamethasone 0.15 mg/kg IV q6 hrs, 15-20 minutes prior to antibiotics, in adults with suspected pneumococcal meningitis.
Nosocomial Meningitis
Vancomycin 15-20 mg/kg IV q8 hrs
+ Cefepime 2 g IV q8 hours or Ceftazidime 2g IV q8 hours or Meropenem 2g IV q8 hours
Catheter-associated bloodstream infection
Vancomycin 15-20 mg/kg IV q8 hrs
- Consider addition of Cefepime 1-2 g IV q8 hrs, Piperacillin-Tazobactam 4.5 g IV q6 hrs, Imipenem 500 mg IV q6 hrs or Meropenem 1 g IV q8 hrs if severely ill, or suspected source is a femoral line, or otherwise at risk for resistant gram negatives.
- Consider echinocandin (e.g. caspofungin) if severely ill and high risk of Candida (e.g TPN, immunocompromised)
