Oral antibiotics on par with IV delivery for endocarditis

A Danish study of 400 patients with infective endocarditis has concluded oral delivery of antibiotics to treat the disease yields similar safety and efficiency as administering the drugs intravenously.

Kasper Iversen, MD, DMSc, and his team posited that in the case of infective endocarditis, an oral alternative to traditional intravenous treatment might cut hospital stays, improve disease outcomes and allow patients the option of outpatient care, alleviating some of the stress and discomfort associated with IV treatment.

“For a large proportion of patients, the main reason for staying in the hospital after the initial phase is to complete intravenous antibiotic treatment,” Iversen, who’s affiliated with Herlev-Gentofte University Hospital and Copenhagen Health Science Partners, and co-authors wrote in the New England Journal of Medicine. “Therefore, if oral antibiotic treatment might be safe and efficient, part of the treatment period for patients in stable condition could take place outside hospitals, without the need for an intravenous catheter.”

The American Heart Association and European Society of Cardiology both recommend that patients with infective endocarditis on the left side of their heart be treated intravenously with antibiotics for up to six weeks after they’re admitted for the condition, the authors said. The team wanted to explore whether, once those patients are stable, a shift from intravenous to oral antibiotics could yield better outcomes.

Iversen et al. recruited 400 patients for their study, all of whom were in stable condition but had endocarditis on the left side of their heart cause by either streptococcus, Enterococcus faecalis, Staphylococcus aureus or coagulase-negative staphylococci. All patients received intravenous treatment for at least 10 days, at which point 199 were randomized to continue intravenous treatment and 201 were switched to oral antibiotics. When possible, patients in the oral antibiotics group were discharged for outpatient treatment.

Antibiotic treatment was completed after a mean 19 days in the intravenously treated group and 17 days in the orally treated group, the authors reported. A primary composite outcome of all-cause mortality, unplanned cardiac surgery, embolic events or relapse of bacteremia with the primary pathogen occurred in 12.1 percent of intravenously treated patients and 9 percent of orally treated patients—a result that met noninferiority criteria.

“The results seemed consistent across prespecified subgroups, including the subgroups defined according to type of valve affected and according to type of treatment (surgery during the disease course or conservative treatment),” Iversen and co-authors wrote. “It should also be noted that the primary outcome seemed similar across the four different bacterial types. However, the trial was not powered to assess the primary outcome in any of the prespecified subgroups.”

The authors said a handful of observational studies and one systematic review have suggested a shift from intravenous to oral therapy can be successful in patients with endocarditis on the right side of the heart, but literature on oral treatment for endocarditis on the left side is “sparse.” Their work adds to that literature, and they recommended physicians use the inclusion criteria from their study when deciding whether a patient could benefit from partial oral therapy.

“In geographic areas with higher rates of antibiotic resistance, these criteria would also be applicable, since they are based on antibiotic treatment guided by state-of-the-art susceptibility testing,” Iversen et al. wrote. “However, the smaller number of effective antibiotics that can be used in areas with a higher degree of antibacterial resistance may represent a limitation.”