A 26-year-old woman comes to the clinic reporting a 3-day history of a burning sensation w… — USMLE Step 2 CK

A 26-year-old woman comes to the clinic reporting a 3-day history of a burning sensation with urination and increased urinary frequency. She has no fever, chills, flank pain, nausea, or vaginal discharge. Her temperature is $37.1^\circ C$ ( $98.8^\circ F$ ), blood pressure is $118/76$ mm Hg, and pulse is $74$ /min. Physical examination reveals mild suprapubic tenderness but no costovertebral angle tenderness. A urine dipstick test is positive for nitrites and leukocyte esterase. A urine pregnancy test is negative. Which of the following is the most appropriate empiric pharmacotherapy for this patient?

Oral nitrofurantoinAnswer
B
Oral ciprofloxacin
C
Intramuscular ceftriaxone
D
Oral amoxicillin
E
Oral azithromycin

Answer

Oral nitrofurantoin

The correct answer is oral nitrofurantoin. This patient has classic symptoms and urinalysis findings of uncomplicated acute cystitis. The most common causative organism is Escherichia coli. In young, non-pregnant women with uncomplicated cystitis, the primary goal is targeted, narrow-spectrum eradication of the pathogen while minimizing collateral damage to the normal flora. First-line empiric regimens include nitrofurantoin (typically given for 5 days), trimethoprim-sulfamethoxazole (given for 3 days, provided local resistance is less than 20%), or a single dose of fosfomycin.

Step-by-Step Solution

Analyze the patient's symptoms and examination findings.

The patient has dysuria, urinary frequency, suprapubic pain, and a positive urine dipstick for nitrites and leukocyte esterase.

These are classic signs of a lower urinary tract infection (UTI).

Determine if the infection is complicated or uncomplicated.

The infection is uncomplicated acute cystitis.

The patient is young, non-pregnant, and lacks systemic symptoms (fever, chills) or upper urinary tract involvement (flank pain, costovertebral angle tenderness).

Select the appropriate guideline-concordant empiric therapy.

Identify first-line oral antibiotics for uncomplicated cystitis.

First-line agents include nitrofurantoin, trimethoprim-sulfamethoxazole, and fosfomycin, avoiding broader spectrum agents to practice good antibiotic stewardship.

Key Concept

First-line empiric therapy for uncomplicated acute cystitis includes oral nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic