The choice of antibiotic for treating infective endocarditis.

The bacteriological spectrum of infective endocarditis is very different when the disease occurs spontaneously from when it follows shortly after cardiac surgery or is associated with narcotic abuse or haemodialysis. It is therefore suggested that two categories of the illness, naturally occurring and extraneous, are recognized. The great majority of cases of naturally occurring infective endocarditis are caused by organisms highly sensitive to penicillin. Oral therapy is nearly always effective in such cases and amoxycillin given with probenecid is recommended as the regime of choice. Extraneous infective endocarditis is most often caused by staphylococci, with Gram-negative bacilli and fungi also quite frequent infecting agents. Intravenous and oral therapy with a variety of antibiotics is discussed in the management of this group.