What is the empiric antibiotic treatment for infective endocarditis?

The empiric antibiotic treatment for infective endocarditis is based on the likely pathogens involved and the patient's risk factors. In cases of suspected infective endocarditis, especially in patients with a history of intravenous drug use or those with prosthetic heart valves, the preferred regimen often includes vancomycin due to its coverage of resistant strains of Staphylococcus aureus, including MRSA.

Gentamicin is typically added to provide synergy, particularly against Enterococcus and some gram-negative bacteria, and to target potential virulent organisms in combination therapy. This combination is effective for both streptococcal and staphylococcal endocarditis, covering a broader spectrum of pathogens that are encountered in these infections.

In contrast, other regimens may lack adequate coverage for the resistant organisms that commonly cause endocarditis. Amoxicillin and clavulanate, for example, are not first-line choices as they do not provide robust coverage for staphylococci. Ceftriaxone and vancomycin offer good coverage but may not provide the necessary synergy and broader coverage that gentamicin supplies. Piperacillin and tazobactam, while having good gram-negative coverage, also do not sufficiently target the resistant staphylococci