Making the Correct Diagnosis: The Cornerstone of Antibiotic Stewardship

Neil Gaffin, MD; Brad Spellberg, MD


May 19, 2017

The correct answer is: E. None of the above. This healthy young man presents with likely allergic rhinitis, which may or may not have a mild acute sinusitis associated with it. In any event, there is no evidence of bacterial infection—there are no fevers, there is no purulence, and conservative management has not failed in this patient.

The itchiness and watering of the eyes and scratching sensation in the throat are typical of seasonal allergies. Antibiotics should not be prescribed; and if a provider prescribes them, the responsible antibiotic steward should actively intervene to stop them.

Fundamental stewardship principles are indeed to use the right drug, at the right dose, for the right duration. Hence, if the correct diagnosis had been acute bacterial sinusitis, and antibiotics were warranted, narrow-spectrum amoxicillin would be preferable to levofloxacin. Broad-spectrum gram-negative coverage, including for Pseudomonas aeruginosa, is not needed for community-onset acute bacterial sinusitis, so fluoroquinolones should not be used. Indeed, fluoroquinolones have a black box warning for such infections due to toxicities such as tendon rupture, encephalopathy, etc.

If levofloxacin is used to treat a pseudomonal infection, the 750-mg daily dose is preferred to the 500-mg daily dose. With respect to duration of therapy, 5 days is sufficient for acute bacterial sinusitis based on multiple randomized controlled trials and meta-analyses.[7] But none of these antibiotic stewardship principles (right drug, right dose, right duration) are relevant when the fundamental problem is a misdiagnosis.

None of these antibiotic stewardship principles (right drug, right dose, right duration) are relevant when the fundamental problem is a misdiagnosis.

This case underscores that the underlying principle of antibiotic stewardship is to make an accurate diagnosis, which then leads to appropriate therapeutic planning. Patients who do not have bacterial infections should not be given antibiotics at all.

Case #2: An 80-Year-Old Who Is More Tired Than Usual

An 80-year-old woman residing in a nursing facility was noted to be "more tired" than usual. Her family was very concerned that she might have a urinary tract infection (UTI) based on past diagnoses made when the patient's activity level had decreased. In addition, the patient's nurse noted that her urine was malodorous. The family requested that her physician order urine testing. The patient denied dysuria, increased frequency, or urgency.

On exam, the patient was afebrile and hemodynamically stable, with no suprapubic or flank tenderness. Urinalysis revealed >145 white blood cells (WBCs), >182 red blood cells, and negative nitrate. Urine culture grew 50,000-100,000 colony-forming units/mL of Klebsiella pneumoniae. A 5-day course of trimethoprim-sulfamethoxazole was prescribed based on susceptibility testing.


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