Combination Antibiotic Therapy in Staphylococcal Endocarditis

The well-demonstrated in vitro synergism of penicillin and aminoglycoside antibiotics against various groups of streptococci,¹⁻⁶and their in vivo efficacy in the treatment of endocarditis caused byStreptococcus viridansand enterococci have been the subject of continued interest.⁶⁻¹³Importantly, Durack et al⁸and Sande and Irvin¹⁴have demonstrated a definite in vivo correlation with in vitro penicillin-aminoglycoside synergism in animals with aS viridansendocarditis model. Recently, a similar correlation also has been demonstrated with the use of aStaphylococcus aureusendocarditis model and penicillin-gentamicin therapy.¹⁵The 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-sensitiveS aureusin which the clinical response to methicillin sodium treatment alone was not satisfactory. The addition of gentamicin sulfate