Current Evidence on Oral Antibiotics for Infective Endocarditis: A Narrative Review

Infective endocarditis (IE) continues to be associated with high morbidity and mortality, even when treated with optimal antibiotic regimens. The selection of treatment depends on the causative pathogen, its antibiotic susceptibility profile, local and systemic complications and the presence of prosthetic materials or devices. Standard therapy typically involves 4-6 weeks of intravenous (IV) bactericidal therapy. However, there are instances in which IV antibiotic administration may be challenging due to cost, complications of IV access, adverse side-effects of the medication or concerns for misuse of the IV line. Current clinical guidance from the American Heart Association and the European Society of Cardiology cite scenarios where oral antibiotics can be considered for treatment of IE, though these situations are relatively infrequent and data to show their non-inferiority limited. Recently, a well-designed randomized clinical study reported favorable outcomes for partial oral antimicrobial therapy regimens given to patients with staphylococcal, streptococcal and enterococcal IE deemed clinically stable and without complications such as perivalvular abscess. Oral antibiotics, usually given in combination, were selected by infectious disease providers for their favorable pharmacologic properties and predicted bactericidal activity. There was a careful selection of patients who were transitioned to oral regimens. Before recommending routine use of oral antibiotics in the care of patients with IE, additional studies that better define eligible patients and that use regimens available in the countries that adopt this practice should be performed. If further studies confirm non-inferior outcomes with partial oral antibiotics for the treatment of IE, medical treatment could be delivered in a simpler, more costeffective manner, and likely with lower rates of adverse side-effects.