Infective endocarditis prevention

Red Flags

New murmur with fever in patient with prosthetic valve, prior IE, or unrepaired cyanotic congenital heart disease — admit; blood cultures × 3, echocardiography, urgent cardiology^[1]
Suspected IE during dental or invasive procedure period — culture and treat early; multidisciplinary review^[1]
Heart-brain embolic event in IE — emergency MDT (cardiology, cardiac surgery, neurology); valve surgery often indicated despite stroke^[1]
Prophylaxis failure or recurrent IE — investigate dental/other portals; cardiology and cardiothoracic surgery; oral health intensification^[1]

First-line treatment

Interventions

Restrict antibiotic prophylaxis to highest-risk patients^[1]
AHA/ACC: prosthetic heart valve, prior IE, unrepaired or repaired cyanotic congenital heart disease, cardiac transplant valvulopathy. Lower-risk conditions (mitral valve prolapse, bicuspid aortic valve, rheumatic heart disease without prior IE) NO LONGER require routine prophylaxis
Limit prophylaxis to high-risk procedures^[1]
Dental procedures involving gingival/periapical manipulation or oral mucosa perforation; respiratory procedures involving incision/biopsy; infected GI/GU tissue procedures. Routine GI/GU procedures and skin procedures generally NOT covered
Oral health as primary prevention^[1]
Twice-yearly dental review, daily brushing and flossing, treat periodontitis and dental caries proactively; daily bacteraemia from poor oral hygiene exceeds procedure-related risk
Patient and family education^[1]
Wallet card with risk status and prophylaxis regimen; counsel about delayed prophylaxis (up to 2 h post-procedure if missed pre-procedure dose); avoid IV drug use; manage piercings/tattoos with hygienic practice; report unexplained fever to clinician promptly

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Amoxicillin (oral)^[1]	Aminopenicillin	2 g PO 30–60 min before high-risk procedure	50 mg/kg PO 30–60 min before procedure (max 2 g)	First-line for high-risk patients undergoing high-risk procedures; if missed, give within 2 h post-procedure
Ampicillin (parenteral, when oral not possible)^[1]	Aminopenicillin	2 g IV/IM 30–60 min before procedure	50 mg/kg IV/IM (max 2 g)	Alternative if oral route unavailable; cefazolin or ceftriaxone same dose where penicillin not contraindicated
Cephalexin (penicillin allergy without anaphylaxis)^[1]	First-generation cephalosporin	2 g PO 30–60 min before procedure	50 mg/kg PO (max 2 g)	First-line in non-severe penicillin allergy; cross-reactivity rare; avoid in immediate hypersensitivity (urticaria, angioedema, anaphylaxis)
Azithromycin or clarithromycin (severe penicillin allergy)^[1]	Macrolide	500 mg PO 30–60 min before procedure	15 mg/kg PO (max 500 mg)	Severe penicillin allergy with anaphylaxis history; alternative doxycycline 100 mg per AHA 2021 update; QTc caution with concurrent QT-prolonging agents
Clindamycin (alternative — caution per AHA 2021)^[1]	Lincosamide	600 mg PO 30–60 min before procedure	20 mg/kg PO (max 600 mg)	Used historically; AHA 2021 update recommends azithromycin/doxycycline preferred over clindamycin due to C. difficile signal; reserve for cases where alternatives contraindicated

Amoxicillin (oral)^[1]

Aminopenicillin

Adult: 2 g PO 30–60 min before high-risk procedure
Paediatric: 50 mg/kg PO 30–60 min before procedure (max 2 g)

First-line for high-risk patients undergoing high-risk procedures; if missed, give within 2 h post-procedure

Ampicillin (parenteral, when oral not possible)^[1]

Aminopenicillin

Adult: 2 g IV/IM 30–60 min before procedure
Paediatric: 50 mg/kg IV/IM (max 2 g)

Alternative if oral route unavailable; cefazolin or ceftriaxone same dose where penicillin not contraindicated

Cephalexin (penicillin allergy without anaphylaxis)^[1]

First-generation cephalosporin

Adult: 2 g PO 30–60 min before procedure
Paediatric: 50 mg/kg PO (max 2 g)

First-line in non-severe penicillin allergy; cross-reactivity rare; avoid in immediate hypersensitivity (urticaria, angioedema, anaphylaxis)

Azithromycin or clarithromycin (severe penicillin allergy)^[1]

Macrolide

Adult: 500 mg PO 30–60 min before procedure
Paediatric: 15 mg/kg PO (max 500 mg)

Severe penicillin allergy with anaphylaxis history; alternative doxycycline 100 mg per AHA 2021 update; QTc caution with concurrent QT-prolonging agents

Clindamycin (alternative — caution per AHA 2021)^[1]

Lincosamide

Adult: 600 mg PO 30–60 min before procedure
Paediatric: 20 mg/kg PO (max 600 mg)

Used historically; AHA 2021 update recommends azithromycin/doxycycline preferred over clindamycin due to C. difficile signal; reserve for cases where alternatives contraindicated

Safety-net

Daily oral hygiene and twice-yearly dental review prevent more endocarditis than any antibiotic — make these your priority^[1]
Tell every dentist, GP, surgeon, and pharmacist about your prosthetic valve, prior IE, or congenital heart disease — informs procedure planning^[1]
Unexplained fever, fatigue, weight loss, or new heart murmur — same-day medical review with blood cultures BEFORE empiric antibiotic^[1]

Referral criteria

Suspected infective endocarditisCardiology with blood cultures, echocardiogram, infectious diseases^[1]
Pre-cardiac surgery or pre-prosthetic valve placementDental review for clearance and oral health optimisation^[1]
Recurrent IE despite optimal preventionTertiary cardiac and infectious diseases multidisciplinary team^[1]
Penicillin allergy requiring documentation/de-labellingAllergy clinic for risk assessment and possible delabelling^[1]

Clinical summary

Risk-based antibiotic prophylaxis and oral health for adults at high risk of infective endocarditis undergoing dental and other procedures.

References

1.AHA/ACC Guideline for the Prevention of Infective Endocarditis (2007, updated 2017 and 2021); ESC 2023; NICE CG64 (2008/2016) (2021)