Treatment And Antibiotic Prophylaxis Of Infective Endocarditis

Let’s take a recap on what we have discussed so far about Infective endocarditis before focusing on its treatment and prophylaxis. The heart valves and endocardium may be the seat of direct invasion by microbes. Virulent organisms such as staphylococcus aureus, streptococcus hemolyticus and pneumococci produce acute ulcerative endocarditis during the course of a septicemia and these affect normal valves. Fortunately, this complication is rare. More often infective endocarditis manifests as a subacute illness. In this case, the organisms are of low virulence and the disease supervenes on already damaged tissues.

Treatment

After collecting blood for microbiological studies, specific treatment should be started. Penicillin is started initially, since it is effective against Streptococcus viridians which is the commonest etiological agent. High doses of crystalline penicillin are given (1 mega unit intramuscular or intravenous every 6 hours) along with streptomycin 1g intramuscularly daily. An alternate regimen is to give 20 mega units of crystalline penicillin dissolved in 600 ml of5% glucose and given intravenously in 600 ml of 5% glucose and given intravenously slowly over 24 hours along with streptomycin 1g intramuscularly. These two antibiotics act synergically. The antibiotic regimen is revised and modified suitably on the basis of microbiological reports.

High blood concentration of penicillin can be achieved by the concurrent administration of probenecid (0.5g 6 hours daily) which blocks its renal excretion. The high dose of antibiotic has to be continued for a minimum period of four to six weeks in order to effect cure and avoid relapse.

Surgery

When medical treatment fails to clear the infection, the underlying abnormality may have to be corrected surgically and this has to be done as a lifesaving procedure.

Prognosis

The prognosis of infective endocarditis caused by S. Viridas has improved considerable after the advent of penicillin, but fungal endocarditis is less amenable to treatment.

Prevention

Infective endocarditis is largelt a preventable disease. In all patients with heart disease, all febrile episodes and minor surgery should be covered with antibiotics.