Infective endocarditis: right-sided Staphylococcus endocarditis may be treated with nafcillin plus tobramycin.

Clinical bottom line (level 4)

  1. 94% of selected patients with right-sided Staphylococcus endocarditis were treated safely and effectively with a two week course nafcillin plus tobramycin.
Chambers et al: Annals of Internal Medicine 1988; 109: 9619-9624
Expires July 2003

The study

Case series with ?objective ?blinded outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, USA (1983 to 1987)

53 patients (aged mean 35 years, 53% female) intravenous drug users with 'relatively uncomplicated' right-sided Staphylococcus aureus endocarditis, defined by clinical and echocardiographic criteria

Excluded if
  • hospital-acquired endocarditis
  • allergic to study drugs
  • serum creatinine level 220 µ mol/l or more
  • presence of other infectious complications
  • meningitis
  • methicillin-resistant clinical isolate
  • evidence of aortic or mitral valve infection


    • Patients received:
    • nafcillin, 1.5 g iv every four hours plus tobramycin in 1 mg/kg iv every eight hours for 14 days (n=50)
    • (for patients allergic to penicillin) vancomycin, 30 mg/kg per day iv, in two or three divided doses plus tobramycin in 1 mg/kg intravenously every eight hours for 14 days (n=3)


    100% followed for 4-6 weeks after therapy end
    Outcomes studied:
  • bacteriological cure eradication of S. aureus from the blood four weeks after end of therapy
  • clinical cure (blood results unavailable at 4 weeks or more) absence of signs or symptoms of endocarditis for two months

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    bacteriological cure 4-6 weeks after therapy end 44/50 88%
    (79% to 97%)
    clinical cure 4-6 weeks after therapy end 4/50 2.2%
    (0.0% to 9.4%)

    • 88% used heroin, 74% used cocaine, 18% used amphetamines. The median age of intravenous drug abuse was 7.5 years. 32% had a previous history of endocarditis. The median duration of symptoms before admission was four days.8
    • 26 patients who were followed for periods ranging from 2.5 to 35 months remained well and free of infections requiring hospitalisation.
    • Two of the three failures were associated with management errors (break in therapy and failure to drain abscess)- had these not occurred the results might have been even better.

    Citation

    1. Chambers HF, et al: Right-sided staphylococcus aureus endocarditis in intravenous drug abusers: two-week combination therapy. Annals of Internal Medicine 1988; 109: 9619-9624
    Search Terms: endocarditis and therapy
    Contributor: Sumit Dhingra, Carl Heneghan and Chris Ball, July 2000
    Reviewer:

    Clinical Question.
    Patient infective endocarditis
    Intervention or Exposure antibiotics
    Outcome staph endocarditis