INFECTIVE ENDOCARDITIS

I. Prophylaxis--Guidelines per AHA 2007 (http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.106.183095)

1. Note that these guidelines update prior, much more aggressive guidelines.  Update was based on review of evidence and finding that many of the assumptions on which the older guidelines were based are probably invalid (like that bacteremia from dental procedures is qualitatively more severe than bacteremia from everyday activities like toothbrushing).
2. As of 2007 there are no publiched randomized placebo-controlled studies to evaluate efficacy of abx for prophylaxis of endocarditis prior to dental, GI, or GU procedures
3. Endocarditis prophylaxis "may be reasonable...although its effectiveness is unknown" for patients with any of the risk factors for severe complications of endocarditis listed below, for the following procedures:
   1. Dental procedures in which the gingiva or periapical region of a tooth are manipulated, or in which the oral mucosa is perforated (Class IIb recommendation)
   2. Invasive procedure of respiratory tract that involves incision or biopsy of respiratory mucosa (Class IIb recommendation)
   3. NO prophylaxis recommended for GI or GU procedures, EXCEPT:
      1. Elective urinary tract manipulation in presence of a known enterococcal urinary tract infection or colonization (in that case, "may be reasonable" to treat to eradicate enterococci from the urine; Class IIb recommendation)
      2. Non-elective urinary tract manipulation in presence of a known enterococcalurinary tract infection or colonization (in that case, pre-treat with a med effective against enterococci; Class IIb recommendation e.g. amoxicillin, ampicillin, or vancomycin).
4. Risk factors for severe complications of endocarditis, for which endocarditis prophylaxis may be appropriate:
   1. Prosthetic Cardiac Valve
   2. History of prior infective endocartitis
   3. History of cardiac transplantation with subsequent cardiac valvulopathy
   4. Congential Heart Disease AND
      1. No h/o repair (or repair consisting only of palliative shunts and conduits)
      2. History of complete repair in prior 6mos
      3. History of repair but residual defects at or adjacent to the site of a prosthetic patch or device
5. Antibiotic regimens:
   1. Timing
      1. Single dose 30-60min before the procedure; may be administered up to 2h after procedure if inadvertently omitted
   2. Drugs
      1. Amoxicillin 2g (or, if child, 50mg/kg) PO is first-line
      2. If unable to take oral meds:
         1. Ampicillin 2g (or, if child, 50mg/kg) IM/IV, OR
         2. Cefaxolin or Ceftriaxone 1g (or, if child, 50mg/kg) IM/IV
      3. If allergic to penicillins or ampicillin:
         1. Cephalexin 2g (or, if child, 50mg/kg) PO, OR
         2. Clindamycin 600mg (or, if child, 20mg/kg) PO, OR
         3. Azithromycin or Clarithromycin 500mg (or, if child, 15mg/kg) PO
      4. If allergic to penicillins or ampicillin AND unable to take oral meds:
         1. Cefazolin or ceftriaxone 1g (or, if child, 50mg/kg) IM/IV (don't use if h/o anaphylaxis, angioedema, or urticaria w/penicillins), OR
         2. Clindamycin 600mg (or, if child, 20mg/kg) IM/IV

II. Treatment

1. Typically treated with antibiotics x 4-6wks
2. In a retrospective study in 252 pts with infectious endocarditis (none were IV drug users), those who underwent early surgery (replacement of infected valve before completion of 4-6wks of antibiotics) vs. those who did not, mortality over 8y f/u was sig. lower in the former (40% vs. 65%) (Clin. Inf. Dis. 33:1636, 2001--AFP)