Seventeen patients with subacute bacterial endocarditis caused by penicillinsensitive streptococci were treated for 2 weeks with a combination of phenoxymethyl penicillin (penicillin V) by mouth and streptomycin intramuscularly. No bacteriological relapses were observed in follow-up periods ranging from 6 to 54 months. Three patients died 22 to 34 months after treatment, one from burns, one from cardiac failure, and one suddenly, causes unknown.
MORE THAN 17 years have elapsed sinceFlorey's original report that penicillin might be effective in the treatment of subacute bacterial endocarditis. The intervening years have provided solid proof of lasting cure and, what could not have been anticipated, evidence that most patients emerge from the infection with hearts no worse off than when the infection began.1,2 Nevertheless, opinions of authorities still differ in regard to choice of anti¬ biotics, dosage, and duration of therapy.3 Some recommend penicillin G,4 some penicillin V,3 and others 8 penicillin plus streptomycin. Some are con¬ vinced that 2 weeks of treatment suffice,6 while others adhere to longer regimens.4 The purpose of this paper is to record experience with a regimen, embodying 2 weeks of phenoxymethyl penicillin (penicillin V) by mouth and streptomycin given intramuscularly, in the treatment of subacute endo¬ carditis caused by penicillin-sensitive streptococci.
Material and MethodsThe patients include 12 adults (cases 1, 2, 9, and 11 were originally reported in 1957)7 and 5 chil¬ dren. The adults were treated at the Cincinnati General Hospital, the Cincinnati Veterans Hospital, or the Jewish Hospital in consultation with one of the authors. The children were all treated at the Cincinnati Children's Hospital.Phenoxymethyl penicillin was administered by mouth at 4-hour intervals. All the children and 7 of the adults were given 600 mg. per dose; the other 5 adults received 500, 625, 625, 750, and 750 mg. respectively. Streptomycin was given as streptomy¬ cin sulfate or as an equal mixture of streptomycindihydrostreptomycin. The adult dose was 1 gm. every 12 hours, the children's dose 0.5 gm. every 12 hours. Treatment was continued 14 or 15 days.
ResultsIn Vitro Sensitivity of Streptococci.-All strepto¬ cocci in this series were highly sensitive to penicil¬ lin. The data in Table 1 demonstrate that the mini¬ mal inhibiting concentration (MIC) of this antibiotic varied from 0.003 to 0.2 meg. per ml., for 10 strains tested by a 2-fold serial dilution technique in yeast beef broth. The penicillin sensitivity of the other 7 strains was tested by a standard disc test. In 7 in¬ stances the minimal inhibiting concentration of streptomycin was measured by a 2-fold serial dilu¬ tion test in tryptone broth containing 7% human or sheep erythrocytes. The MIC for 7 of these strains varied from less than 0.006 to 25 meg. per ml.; 3 strains failed to grow in this medium. Clinical Analysis of Cases.-Essential clinical data of the 17 cases are presented in Table 2. It is note¬ worthy that 6 of the 12 adults were over 6...
