The use of beta-lactam antibiotics in the treatment of septicaemia and endocarditis.

Despite the availability of numerous beta-lactam antibiotics, benzylpenicillin remains the most important beta-lactam antibiotic in the treatment of bacterial endocarditis. Penicillin alone and in combination with an aminoglycoside is effective in the treatment of endocarditis due to all streptococci, Streptococcus pneumoniae, penicillin-susceptible Staphylococcus aureus, Haemophilus aprophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Listeria monocytogenes. Oral phenoxymethylpenicillin in combination with streptomycin is effective in treating endocarditis due to viridans streptococci. Ampicillin is effective in endocarditis due to Haemophilus influenzae, H. parainfluenzae, H. paraphrophilus, Listeria monocytogenes and Escherichia coli. Oral amoxicillin with gentamicin has been used to treat enterococcal endocarditis. The penicillinase-resistant penicillins are effective in treating S. aureus endocarditis. Carbenicillin or ticarcillin in combination with tobramycin or gentamicin are used to treat endocarditis due to Serratia marcescens and Pseudomonas aeruginosa. The use of piperacillin in combination with tobramycin against P. aeruginosa endocarditis has been associated with failure and increased resistance. The cephalosporins have been used to treat endocarditis caused by susceptible organisms. There have been few data on the efficacy of the newer cephalosporins in treating endocarditis. They have been used to treat septicaemia due to susceptible organisms with good results.