Infective endocarditis: oral antibiotics were probably effective for iv drug users.

Clinical bottom line (level 2b-)

  1. Oral antibiotics were probably as effective as intravenous antibiotics in intravenous drug misusers with right-sided staphylococcus endocarditis.
  2. Patients had less liver damage (NNT = 3 at unknown) , and kidney damage (NNT = 4 at unknown) .
Heldman et al: American Journal of Medicine 1996; 101: 68-76
Expires July 2003

The study

Unblinded concealed randomised trial without intention-to-treat
Setting: university hospital, USA, 1990 to 1993

89 patients (aged mean 35 years, 55% male) admitted with a febrile illness compatible with right-sided staphylococcus endocarditis and sustained staphylococcal bacteraemia on two or more blood cultures (HIV was present in 61/89: 69%)

Excluded if
  • <18 years old
  • required other antibiotics
  • microbial resistance to ciprofloxacin
  • left-sided endocarditis, meningitis, osteomyelitis
  • unable to take oral medication
  • prosthetic cardiovascular device
  • pregnant
  • sustained hypotension (systolic < 90 mmHg after fluid resuscitation)
  • respiratory failure requiring mechanical ventilation


    • Note:
  • Patients were randomised before definite diagnosis of infective endocarditis was made.


    • Control Group: (n = , analysed): oxacillin 2 g iv every 4 hours, or vancomycin 1 g every 12 hours for penicillin-allergic patients, plus gentamicin 2 mg/kg iv every hour for the first 5 days, then changed to oral medication
    Experimental Group: (n = , analysed): ciprofloxacin 750 mg po twice daily and rifampin 300 mg po twice daily

    47% followed for 28 days
    Outcome notes:
    • treatment failure : development of left-sided endocarditis, heart block of any degree, congestive heart failure, respiratory failure requiring mechanical ventilation , hypotension, sustained or recurrent bacteraemia after 10 days of treatment, metastatic infection (secondary meningitis, osteomyelitis), death
    • hepatotoxicity : rise in serum transaminases from normal to >150 IU/l, or from an abnormal baseline to a threefold increase, associated with at least 7 days of study drug treatment
    • nephrotoxicity : 50% reduction in calculated creatinine clearance

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    treatment failure 28 days 3
    (12.0%)    		 1
    (5.26%)    		 56%
    (-290% to 95%)    		 6.74%
    (-9.48% to 23.0%)    		 15
    (NNT = 4 to infinity;
    NNH = 11 to infinity)
    hepatotoxicity - unknown 13
    (33.3%)    		 1
    (2.80%)    		 92%
    (39% to 99%)    		 30.5%
    (14.8% to 46.3%)    		 3
    (2 to 7)
    nephrotoxicity - unknown 10
    (25.6%)    		 0
    (0.00%)    		 100%
    (% to %)    		 25.6%
    (11.9% to 39.4%)    		 4
    (3 to 8)

    Comments

    1. Study was too small and the loss to follow-up too great to show any potential increased risk from using oral antibiotics.

    Citation

    1. Heldman AW, et al: Oral antibiotic treatment of right-sided staphylococcal endocarditis in injection drug users. Prospective randomized comparison with parenteral therapy. American Journal of Medicine 1996; 101: 68-76
    Search Terms: endocarditis, treatment, intravenous in Medline
    Contributor: Carl Heneghan, Sumit Dhingra and Chris Ball, July 2000
    Reviewer:

    Clinical Question.
    Patient drug misusers
    Intervention or Exposure oral antibiotics
    Comparison iv antibiotics
    Outcome effect