What is the recommended IV prophylaxis regimen for patients at high risk of developing infective endocarditis?

IV Prophylaxis for Infective Endocarditis

For patients unable to take oral medications who require infective endocarditis prophylaxis before dental procedures, administer ampicillin 2 g IV or IM (50 mg/kg for children, not exceeding adult dose) as a single dose 30-60 minutes before the procedure. 1

High-Risk Patients Requiring Prophylaxis

Antibiotic prophylaxis is recommended only for patients with the highest risk of adverse outcomes from infective endocarditis, not simply those with increased lifetime risk. 1

The highest-risk cardiac conditions include:

• Prosthetic cardiac valves or prosthetic material used for valve repair (including TAVR valves) 1
• Previous history of infective endocarditis 1
• Specific congenital heart disease:
  • Unrepaired cyanotic CHD, including palliative shunts and conduits 1
  • Completely repaired CHD with prosthetic material during first 6 months post-procedure 1
  • Repaired CHD with residual defects at or adjacent to prosthetic patch/device sites 1
• Cardiac transplant recipients who develop cardiac valvulopathy 1

IV Antibiotic Regimens

Standard IV Regimen (Non-Allergic Patients)

Ampicillin 2 g IM or IV (50 mg/kg for children, maximum 2 g) given 30-60 minutes before the procedure 1

Alternative: Cefazolin or ceftriaxone 1 g IM or IV (50 mg/kg for children) given 30-60 minutes before the procedure 1

IV Regimen for Penicillin-Allergic Patients

Cefazolin or ceftriaxone 1 g IM or IV (50 mg/kg for children) given 30-60 minutes before the procedure 1

Important caveat: Cephalosporins should not be used in patients with a history of anaphylaxis, angioedema, or urticaria with penicillins or ampicillin 1

For severe penicillin allergy: Clindamycin 600 mg IM or IV (20 mg/kg for children) given 30-60 minutes before the procedure 1

Procedures Requiring Prophylaxis

Prophylaxis is indicated only for dental procedures involving:

• Manipulation of gingival tissue 1
• Manipulation of the periapical region of teeth 1
• Perforation of oral mucosa 1

Procedures NOT Requiring Prophylaxis

Prophylaxis is no longer recommended for: 1

• Gastrointestinal procedures (including esophagogastroduodenoscopy, colonoscopy) 1
• Genitourinary procedures (including cystoscopy) 1
• Respiratory tract procedures (unless involving incision of respiratory mucosa in high-risk patients) 1
• Transesophageal echocardiography 1
• Routine dental procedures without mucosal manipulation (X-rays, orthodontic appliance adjustments) 1

Exception: In high-risk patients with active GI or GU tract infections, antibiotic therapy to prevent wound infection or sepsis (not specifically for endocarditis prophylaxis) is reasonable 1

Critical Timing Considerations

• Administer antibiotics 30-60 minutes before the procedure to ensure adequate tissue concentrations 1
• Single pre-procedure dose is sufficient; post-procedure antibiotics are not recommended for prophylaxis 2
• For patients already on antibiotic therapy, select an antibiotic from a different class rather than increasing the current antibiotic dosage 2

Rationale for Restrictive Approach

The major shift toward limiting prophylaxis is based on several key principles: 1

• Infective endocarditis is more likely from daily bacteremia (tooth brushing, chewing) than from isolated dental procedures 1
• Prophylaxis may prevent an exceedingly small number of cases even if 100% effective 1
• The risk of antibiotic-associated adverse effects exceeds the benefit from prophylactic therapy 1
• Optimal oral hygiene and regular dental care are more important than prophylactic antibiotics for reducing endocarditis risk 1

Recent evidence from a 2022 case-crossover study demonstrated a significant temporal association between invasive dental procedures and subsequent infective endocarditis in high-risk individuals (OR: 2.00), with antibiotic prophylaxis associated with significant reduction in IE incidence (OR: 0.49), supporting current guideline recommendations. 3

Common Pitfalls to Avoid

• Do not prescribe prolonged antibiotic courses when only a single pre-procedure dose is indicated 2
• Do not recommend prophylaxis for all patients without appropriate risk stratification 2
• Do not use cephalosporins in patients with immediate-type hypersensitivity reactions to penicillins 1
• Do not exceed maximum pediatric doses (should not exceed adult dose of 2 g for ampicillin) 1, 4
• Do not administer antibiotics too early or after incision, as this reduces effectiveness 4