Infections / Antibiotics
- In patients with a suspected infection,
- Determine the correct tools (e.g., swabs, culture/transport medium), techniques, and protocols for cultures,
- Culture when appropriate (e.g., throat swabs/sore throat guidelines).
- When considering treatment of an infection with an antibiotic, do so
- Judiciously (e.g., delayed treatment in otitis media with comorbid illness in acute bronchitis),
- Rationally (e.g., cost, guidelines, comorbidity, local resistance patterns).
- Treat infections empirically when appropriate (e.g., in life threatening sepsis without culture report or confirmed diagnosis, candida vaginitis post-antibiotic use).
- Look for infection as a possible cause in a patient with an ill defined problem (e.g., confusion in the elderly, failure to thrive, unexplained pain [necrotizing fasciitis, abdominal pain in children with pneumonia]).
- When a patient returns after an original diagnosis of a simple infection and is deteriorating or not responding to treatment, think about and look for more complex infection. (i.e., When a patient returns complaining they are not getting better, don’t assume the infection is just slow to resolve).
- When treating infections with antibiotics use other therapies when appropriate (e.g., aggressive fluid resuscitation in septic shock, incision and drainage abscess, pain relief).
- In patients requiring antibiotic therapy, make rational choices (i.e., first-line therapies, knowledge of local resistance patterns, patient’s medical and drug history, patient’s context).
- In patients with a clinical presentation suggestive of a viral infection, avoid prescribing antibiotics.
- In a patient with a purported antibiotic allergy, rule out other causes (e.g., intolerance to side effects, non-allergic rash) before accepting the diagnosis.
- Use a selective approach in ordering cultures before initiating antibiotic therapy (usually not in uncomplicated cellulitis, pneumonia, urinary tract infections, and abscesses; usually for assessing community resistance patterns, in patients with systemic symptoms, and in immunocompromised patients).
- In urgent situations (e.g., cases of meningitis, septic shock, febrile neutropenia), do not delay administration of antibiotic therapy (i.e., do not wait for confirmation of the diagnosis)
Example First-Line Therapies
- Base on local resistance patterns, patient's medical and recent antibiotic history
Urinary Tract Infection
- Women/Pregnant: Nitrofurantoin 100mg PO BID x 5-7d
- Man/Complicated/Pyelonephritis: Ciprofloxacin 500mg PO BID x 7d
- Pediatrics: Amoxicillin 50 mg/kg/day PO ÷ TID x 5d afebrile, 10d febrile
- Complicated: Cefixime 16mg/kg first day, then 8mg/kg daily
Uncomplicated Cellulitis (no MRSA coverage)
- Adult: Cefadroxil 1g PO daily (or BID) x 5-14d
- Pediatrics: Cephalexin 50-100mg/kg/d ÷ QID x 10-14d
Acute Otitis Media
- Adult: Amoxicillin 500mg PO TID x 5-7d
- Pediatrics: Amoxicillin 90 mg/kg/day PO ÷ BID x 5d-10d (10d if <2yo or severe symptoms)
- Ciprodex otic suspension 4 drops BID x 5d
- Adult: Penicillin V 600mg PO BID x 10d
- Pediatrics: Amoxicillin 50 mg/kg PO daily (max 1g/day) x 10d
Community Acquired Pneumonia
- Adult: Clarithromycin 500mg PO BID x 7d (or Amoxicillin 1g PO TID x7d if do not need to cover atypicals)
- Pediatrics: Amoxicillin 90mg/kg/day (max 3g/day) ÷ TID x 7-10d
- Adult: Amoxicillin 500mg PO TID x 5-10d
- Pediatrics: Amoxicillin 90mg/kg/day (max 2g/day) ÷ BID x 10-14d
- Second-line or if suspect resistance (S pneumo) Amox/Clav 40-80mg/kg/day ÷ BID (or 875/125 mg PO BID)
- Metronidazole 500mg PO BID x 7d
Herpes Simplex Virus
- First episode Acyclovir 400mg PO TID x 7-10d
- Recurrent Episode: Acyclovir 400mg PO TID x 5d (or 800mg PO TID x 2d)
- Ceftriaxone 250mg IM or Cefixime 800mg PO x1 + Azithromycin 1g PO x1 or Doxycycline 100mg PO BID x 7d
Moderate-Severe Gastroenteritis (>3BM/d, blood, fever)
- Consider Cipro 500mg PO BID x 3 days or 750mg PO x1
- Consider Azithromycin 1g PO x1 if travel to Asia (resistance to fluoroquinolones)
- Vancomycin 125mg PO QID x 10-14d
- Pediatrics: 40mg/kg/d PO (max 2g/d) ÷ TID-QID x 10-14d
Peptic Ulcer Disease (non-NSAID related)
- PPI PO BID + Amoxicillin 1g PO BID + Clarithromycin 500mg PO BID x14d (eg. HP-PAC)
- Second-line or if high resistance, add Metronidazole 500mg PO BID (CLAMET)
- Stop antibiotic, and avoid further antibiotics until cleared
- Unlikely true IgE-mediated allergy
- IgE-independent reaction (eg. Red Man Syndrome with vancomycin)
- Delayed T-cell reaction (usually concomitant viral infection, eg EBV)
- Rule out
- Serum Sickness (Type 3) - vasculitic rash, arthralgias, flu-like symptoms, fever
- DRESS (fever, rash, lymphadenopathy, blood count abnormality [eosinophilia, thrombocytopenia])
- SJS/TEN (desquamation, positive Nikolsky's sign, mucosal-involvement)
- Referral to Allergy for challenge testing
- Unlikely true IgE-mediated allergy