NAPLEX Question of the Week: Infectious Diseases
Very excited to launch a NAPLEX question of the Week for members of Access Pharmacy! Each week we will detail a question with rationale both for correct and incorrect answers to help prepare students to study for this examination. Relevant links to study materials will also be provided. Let's begin!
A 33 year-old female with a past medical history significant for gastroesophageal reflux disease (GERD) and hypertension presents to the emergency department with a hard “pimple” on her right leg that is erythematous and painful (currently erythematous area is about 200 cm2). This has worsened since she first noticed it several days ago which brought her into her physician. She reports a rash to sulfa medications in the past. Her current medications are lisinopril 20mg daily, fluticasone 1 spray each nostril daily, and Ortho Tri-cyclen 1 pill daily. Her vitals are the following: BP 100/60, Heart rate 110, Temperature 102.3 F, Respiratory rate 14. Local MRSA rates are 65%. The decision is made to admit the patient to the medicine ward for management.
Which of the following intravenous agents in addition to incision/drainage of the abscess would be appropriate to treat her acute bacterial skin/skin structure infection (ABSSSI)? Select all that apply.
ABSSSI is one of the most common infections presenting to pharmacists. MRSA is a primary pathogen of these infections, especially when the patient presents with an abscess. Knowing coverage of antibiotics that possess MRSA activity is critical when choosing regimens for patients with these infections.
Answer A is incorrect. Amoxicillin/Clavulanate (Augmentin) is an oral agent, not intravenous. An IV agent with similar antimicrobial coverage is ampicillin/sulbactam (Unasyn). Additionally, Augmentin does not possess MRSA coverage which is critical.
Answer B is incorrect. Ceftaroline is the only beta-lactam with MRSA coverage, not ceftriaxone. Therefore ceftriaxone would be inappropriate.
Answer C is correct. Vancomycin possesses excellent coverage vs. the most common ABSSSI pathogens including MRSA and is available intravenously.
Answer D is correct. Similar to vancomycin, daptomycin possesses excellent coverage vs. the most common ABSSSI pathogens including MRSA and is available intravenously. It is more expensive than vancomycin which is why it often is not first line for treatment of ABSSSI. Additionally, daptomycin is inactivated by pulmonary surfactactant and therefore should not be used for treating pulmonary infections like pneumonia.
Answer E is incorrect. While trimethoprim/sulfamethoxazole (Bactrim or Septra) is available intravenously and has good MRSA coverage, the patient reports a sulfa allergy making this an incorrect choice. Always verify allergies when assessing antimicrobial treatment options in order to make appropriate recommendations.
1. Jahng M, Le J. Skin and Soft Tissue Infections. In: Sutton S. eds. McGraw-Hill's NAPLEX® Review Guide, 2e New York, NY: McGraw-Hill; . http://accesspharmacy.mhmedical.com/content.aspx?bookid=1432§ionid=86378673. Accessed September 17, 2018. https://accesspharmacy.mhmedical.com/content.aspx?bookid=1432§ionid=86378673
2. Acute Bacterial Skin/Skin Structure Guidelines: https://www.ncbi.nlm.nih.gov/pubmed/24973422