The well-demonstrated in vitro synergism of penicillin and aminoglycoside antibiotics against various groups of streptococci,1-6 and their in vivo efficacy in the treatment of endocarditis caused by Streptococcus viridans and enterococci have been the subject of continued interest.6-13 Importantly, Durack et al8 and Sande and Irvin14 have demonstrated a definite in vivo correlation with in vitro penicillin-aminoglycoside synergism in animals with a S viridans endocarditis model. Recently, a similar correlation also has been demonstrated with the use of a Staphylococcus aureus endocarditis model and penicillin-gentamicin therapy.15 The clinical importance of combination therapy in serious infections such as endocarditis lies in its enhancement of bacterial killing, and, thus, in its prevention of further vital tissue destruction.
We report a patient with endocarditis caused by a methicillin-sensitive S aureus in which the clinical response to methicillin sodium treatment alone was not satisfactory. The addition of gentamicin sulfate
Murray HW, Wigley FM, Mann JJ, Arthur RR. Combination Antibiotic Therapy in Staphylococcal EndocarditisThe Use of Methicillin Sodium-Gentamicin Sulfate Therapy. Arch Intern Med. 1976;136(4):480–483. doi:10.1001/archinte.1976.03630040082017