What is the treatment for Enterococcus faecalis infection in a patient with a penicillin and sulfonamide (sulfa) allergy?

From the Guidelines

For treating Enterococcus faecalis in a patient with penicillin and sulfa allergies, vancomycin is the recommended first-line alternative, with a typical dosing for adults of 30 mg/kg/day i.v. in 2 doses, as suggested by the 2015 ESC guidelines 1. The choice of vancomycin is based on its effectiveness against Enterococcus faecalis, including strains with high-level aminoglycoside resistance.

• Vancomycin dosing should be adjusted based on renal function and therapeutic drug monitoring.
• For patients with complicated infections or those who do not respond to vancomycin, consultation with an infectious disease specialist is advisable.
• Alternative options, such as linezolid or daptomycin, may be considered for resistant strains or in cases where vancomycin is not suitable, as discussed in the 2015 American Heart Association scientific statement 1.
• Daptomycin can be used at higher doses of 10 to 12 mg·kg−1·24 h−1, and combination therapy with daptomycin and ampicillin or ceftaroline may be considered in certain cases, as recommended by the American Heart Association 1.
• Allergy testing might be considered to confirm the penicillin allergy, as many patients labeled as allergic can actually tolerate penicillins.
• The management of Enterococcus faecalis infections, especially in patients with penicillin and sulfa allergies, requires careful consideration of the infection site, severity, and local resistance patterns.

From the FDA Drug Label

Vancomycin-Resistant Enterococcus faecium infections, including cases with concurrent bacteremia ZYVOX formulations are indicated in the treatment of the following infections caused by susceptible strains of the designated microorganisms

For Enterococcus faecalis treatment with penicillin and sulfa allergy,

• Linezolid can be considered as an alternative treatment option.
• The FDA label does not explicitly mention Enterococcus faecalis, but it does mention Vancomycin-Resistant Enterococcus faecium infections, which suggests that linezolid may be effective against Enterococcal infections.
• However, it is crucial to note that the label does not provide direct information on the treatment of Enterococcus faecalis with penicillin and sulfa allergy.
• Given the lack of direct information, a conservative clinical decision would be to consult additional resources or an expert in the field to determine the best course of treatment 2 2.

From the Research

Treatment Options for Enterococcus faecalis Infection

• For patients with a penicillin allergy, alternative treatment options for Enterococcus faecalis infection include ampicillin, chloramphenicol, doxycycline, minocycline, and nitrofurantoin, as well as newer antibiotics such as tigecycline, lipoglycopeptides (dalbavancin, oritavancin, and telavancin), and cephalosporins with activity against Enterococcus faecalis (ceftobiprole and ceftaroline) 3.
• However, the optimal therapy for Enterococcus faecalis infections, particularly endovascular infections like endocarditis, is not well established and may require individualized treatment decisions based on the patient's specific clinical and microbiological characteristics 3.

Penicillin Allergy Considerations

• Approximately 10% of the US population reports a penicillin allergy, but clinically significant IgE-mediated or T lymphocyte-mediated penicillin hypersensitivity is uncommon (<5%) 4.
• Patients with a reported penicillin allergy may be at low, moderate, or high risk for an allergic reaction, and evaluation of penicillin allergy is an important tool for antimicrobial stewardship 4.
• For patients with a low-risk allergy history, a direct amoxicillin challenge may be appropriate, while moderate-risk patients can be evaluated with penicillin skin testing 4.

Alternative Antibiotics for Sulfa Allergy

• There is limited information available on the treatment of Enterococcus faecalis infections in patients with a sulfa allergy.
• However, alternative antibiotics such as ampicillin, chloramphenicol, doxycycline, minocycline, and nitrofurantoin may be considered, as well as newer antibiotics like tigecycline and lipoglycopeptides 3, 5.
• The selection of an alternative antibiotic should be based on the patient's specific clinical characteristics, the susceptibility of the Enterococcus faecalis isolate, and the potential for cross-reactivity with other antibiotics 6.