Blood cultures from a patient with suspected infective endocarditis grow viridans streptococci (MIC to penicillin 0.12 mg/L). The patient has no penicillin allergy. What is the preferred antibiotic regimen for native valve endocarditis per ESC 2023 guidelines?
- A Penicillin G 12–18 MU/day IV for 4 weeks
- B Ceftriaxone 2 g/day for 4 weeks ✓
- C Ampicillin + gentamicin for 2 weeks
- D Vancomycin for 6 weeks
Correct answer: B. Ceftriaxone 2 g/day for 4 weeks
Explanation
ESC 2023 endocarditis guidelines recommend ceftriaxone 2 g IV once daily for 4 weeks as preferred monotherapy for penicillin-susceptible viridans streptococcal native valve endocarditis (MIC ≤0.125 mg/L), offering equivalent outcomes to penicillin but with the convenience of once-daily dosing suitable for outpatient parenteral antibiotic therapy (OPAT). Gentamicin combination for 2 weeks is an alternative for uncomplicated cases. Vancomycin is reserved for penicillin-allergic patients.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.