Endocarditis Prophylaxis Prior to Surgery

📋 Key Information Summary

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Antibiotic prophylaxis (AP) for infective endocarditis (IE) is restricted to high-risk cardiac conditions undergoing high-risk procedures — universal AP is not recommended.
High-risk conditions include prosthetic cardiac valves, prior infective endocarditis, and unrepaired cyanotic congenital heart disease (including palliative shunts/conduits).
Procedures requiring prophylaxis are predominantly dental procedures involving gingival or periapical manipulation of teeth, or perforation of oral mucosa.
Respiratory tract procedures involving incision or biopsy of mucosa (e.g., tonsillectomy, adenoidectomy) also warrant prophylaxis in high-risk patients.
Genitourinary and gastrointestinal procedures do not routinely require IE prophylaxis — bacteraemia during these procedures has not been causally linked to IE in epidemiological studies.
First-line regimen: Amoxicillin 2 g PO (adults) or 50 mg/kg (paediatric) 30–60 minutes pre-procedure.
Penicillin allergy / alternative: Clindamycin 600 mg PO (adults) or 20 mg/kg (paediatric) 30–60 minutes pre-procedure.
For patients unable to take oral medication, IV amoxicillin 2 g or IV cefazolin 1 g (if penicillin allergy non-anaphylactic) pre-procedure.
NICE (UK) 2008 guidelines are the most restrictive, recommending no antibiotic prophylaxis at all — even for high-risk patients.
ESC 2015 guidelines and Heart Foundation of Australia support targeted AP for high-risk groups, while emphasising oral hygiene as the primary preventive strategy.
Two doses of post-procedure antibiotics are not recommended by current ESC or Australian guidelines — single pre-procedure dose suffices.
Aboriginal and Torres Strait Islander peoples experience higher rates of rheumatic heart disease and should be assessed individually for AP needs.
All patients at risk of IE should receive regular dental care, patient education about symptoms of IE, and counselling on rigorous oral hygiene.
Australian prescribing aligns with Heart Foundation / Cardiac Society of Australia and New Zealand (CSANZ) endorsement of ESC-class principles with local adaptation.

Introduction & Australian Epidemiology

Infective endocarditis (IE) remains a life-threatening infection of the endocardial surface, typically affecting native or prosthetic heart valves, with an in-hospital mortality of 15–30% despite advances in antimicrobial therapy and surgical intervention. The paradigm for antibiotic prophylaxis (AP) has shifted markedly over the past two decades: whereas broad prophylaxis was once recommended for a wide range of cardiac and procedural combinations, current international consensus restricts AP to high-risk cardiac conditions undergoing high-risk procedures, reflecting the low attributable risk of bacteraemia from most interventions.

In Australia, IE incidence is estimated at 4–7 per 100,000 population per year, with important demographic variation. Aboriginal and Torres Strait Islander Australians experience disproportionately higher rates — approximately 3–5 times the non-Indigenous rate — driven largely by the burden of rheumatic heart disease (RHD) in remote and regional communities. The Australian Institute of Health and Welfare (AIHW) reports that RHD-associated IE remains a leading cause of cardiac morbidity in Indigenous Australians under 50 years of age.

The epidemiological shift from Streptococcus viridans-dominant IE to Staphylococcus aureus-dominant IE, observed internationally and confirmed in Australian registries, has influenced prophylaxis thinking. Health care–associated IE (including intravascular device–related and haemodialysis-associated) now accounts for a substantial proportion of cases, and these are not preventable by dental AP. Nonetheless, dental bacteraemia remains a plausible trigger for IE in susceptible individuals, and targeted AP retains a role in selected patients.

Australian clinical practice is guided by endorsement of European Society of Cardiology (ESC) principles by the Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand (CSANZ), while acknowledging the contrasting NICE position. This guideline synthesises the current evidence, reconciles guideline differences, and provides practical prescribing advice for Australian clinicians.

High-Risk Cardiac Conditions Requiring Prophylaxis

Antibiotic prophylaxis is recommended only for patients with cardiac conditions that confer the highest risk of adverse outcomes from IE. These conditions carry a disproportionate burden of morbidity and mortality, and prophylaxis offers a favourable risk–benefit ratio in this subgroup.

Risk Category	Conditions	Rationale
Highest risk	Prosthetic heart valve (mechanical or bioprosthetic) Prosthetic material used for valve repair (annuloplasty ring, chords) Prior infective endocarditis (any episode, any organism)	Highest mortality and recurrence risk; prosthetic material is a nidus for biofilm; prior IE implies permissive valve pathology
High risk	Unrepaired cyanotic congenital heart disease (CHD), including palliative shunts and conduits Completely repaired CHD with prosthetic material or device during first 6 months post-repair Residual defects at or adjacent to prosthetic patch or device	Turbulent flow and residual shunts predispose to endocardial infection; prosthetic device surfaces are vulnerable during endothelialisation
Additional consideration	Cardiac transplant recipients who develop valvulopathy	Immunosuppression plus valvular dysfunction increases susceptibility

⚠️

Conditions NO LONGER considered high-risk for AP: Mitral valve prolapse (with or without regurgitation), bicuspid aortic valve without regurgitation, rheumatic heart disease without prosthetic material, isolated secundum atrial septal defect, and hypertrophic obstructive cardiomyopathy. These were previously included in older guidelines but have been removed from current ESC and Heart Foundation recommendations.

Rheumatic heart disease (RHD) — special consideration in Australia: While RHD without prosthetic material is no longer universally classified as high-risk, Australian clinicians — particularly those practising in Aboriginal and Torres Strait Islander communities — should exercise clinical judgement. Patients with RHD and significant valvular regurgitation, particularly those awaiting surgery or with haemodynamically significant lesions, may benefit from individualised risk assessment for AP. RHDAustralia guidelines emphasise maintaining a low threshold for AP in this population, given the high background IE incidence.

Procedures Requiring Prophylaxis

Prophylaxis is directed at procedures known to cause significant bacteraemia with organisms capable of colonising damaged endocardium. The evidence base derives from observational studies of bacteraemia frequency and timing, as no randomised controlled trials of AP have been conducted (nor are they likely to be feasible given the low incidence of IE).

Procedures

Dental — AP Recommended

Procedures involving manipulation of gingival tissue, periapical region of teeth, or perforation of oral mucosa: dental extractions, scaling/root planing, periodontal probing, dental implant placement, root canal treatment (instrumentation phase), local anaesthetic injections (intraligamentary).

Setting: Dental surgery / day procedure

Procedures

Respiratory — AP Recommended

Procedures involving incision or biopsy of respiratory mucosa: tonsillectomy, adenoidectomy, bronchoscopy with biopsy, rigid bronchoscopy, sclerotherapy for oesophageal varices.

Setting: Hospital / day surgery

Procedures

NOT Requiring AP

Routine non-invasive dental examinations, dental radiographs, shedding of deciduous teeth, non-invasive periodontal assessment, injection of local anaesthetic (non-intraligamentary), placement/removal of orthodontic appliances, GI endoscopy (with or without biopsy), urinary catheterisation, vaginal delivery, uncomplicated caesarean section, cardiac catheterisation.

Setting: General practice / outpatient

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Key principle: If a dental or respiratory procedure is not performed in an adequately controlled setting (e.g., emergency dental extraction performed in a field or remote clinic), the prophylactic regimen should still be administered. Ensure the antibiotic is given 30–60 minutes before the procedure; giving it after the procedure has inferior evidence and is not recommended by ESC guidelines.

Antibiotic Regimens

Prophylaxis is a single dose of antibiotic administered 30–60 minutes prior to the procedure. No additional post-procedure doses are recommended by current ESC or Australian guidelines.

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Amoxicillin

Amoxil® · Generic · Aminopenicillin

Adult dose 2 g orally, 30–60 minutes before procedure

Paediatric dose 50 mg/kg orally (max 2 g), 30–60 minutes before procedure

Route Oral

Frequency Single dose only

Renal adjustment CrCl <30 mL/min: reduce to 1 g (adult); adjust paeds dose proportionally

Hepatic adjustment Not required

PBS status ✔ PBS General Benefit

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Clindamycin

Dalacin C® · Generic · Lincosamide

Adult dose 600 mg orally, 30–60 minutes before procedure

Paediatric dose 20 mg/kg orally (max 600 mg), 30–60 minutes before procedure

Route Oral

Frequency Single dose only

Renal adjustment Not required for single dose

Hepatic adjustment Use with caution; monitor for C. difficile risk even with single dose

PBS status ✔ PBS General Benefit

Alternative Regimens — Patients Unable to Take Oral Medication

Scenario	Drug	Adult Dose	Paediatric Dose	Route
NPO / sedated patient	Amoxicillin	2 g IV	50 mg/kg IV (max 2 g)	IV over 30 min
Penicillin allergy (non-anaphylactic)	Cefazolin	1 g IV	25 mg/kg IV (max 1 g)	IV or IM
Penicillin allergy (anaphylactic) — IV	Clindamycin	600 mg IV	20 mg/kg IV (max 600 mg)	IV over 20 min
Vancomycin allergy / intolerant	Teicoplanin	400 mg IV	10 mg/kg IV (max 400 mg)	IV over 30 min

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Critical timing: The antibiotic must be present in the bloodstream at the time of the procedure. Administer oral amoxicillin or clindamycin 30–60 minutes before the procedure begins. For IV agents, complete the infusion before the first incision or dental instrumentation. Do not rely on post-procedure dosing.

NICE vs ESC Guidelines — Key Differences

The divergent positions of the European Society of Cardiology (ESC 2015) and the UK National Institute for Health and Care Excellence (NICE 2008, updated 2016) represent the most significant international disagreement in IE prophylaxis. Australian practice aligns more closely with the ESC approach, as endorsed by the Heart Foundation of Australia and CSANZ.

Domain	ESC 2015 (European)	NICE 2008/2016 (UK)	Australian Position
Overall stance	Targeted AP for highest-risk patients	No AP for any patient, any procedure	ESC-aligned: targeted AP for high-risk
Basis for no AP (NICE)	Observational evidence supports benefit in high-risk; no RCT evidence exists either way	Absence of RCT evidence of AP efficacy; procedure-related bacteraemia is common and often transient	Acknowledges lack of RCT but accepts precautionary principle
High-risk conditions	Prosthetic valve, prior IE, cyanotic CHD	N/A — no AP given	Same as ESC
Dental procedures	AP for gingival/periapical/mucosal procedures in high-risk	No AP even for extractions in prosthetic valve patients	AP recommended per ESC
GI / GU procedures	AP not recommended	AP not recommended	AP not recommended
Oral hygiene emphasis	Strong emphasis alongside AP	Primary strategy (replacing AP)	Both — oral hygiene + targeted AP
Post-procedure doses	Not recommended (single dose)	N/A	Single dose only
Year of last update	2015	2016 (review confirmed position)	Ongoing; aligned with ESC

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Why the divergence? NICE adopted a strictly evidence-based medicine (EBM) approach, noting that no randomised controlled trial has demonstrated AP efficacy for IE prevention, and that spontaneous bacteraemia from everyday activities (toothbrushing, chewing) may exceed procedural bacteraemia. The ESC and Heart Foundation adopt a precautionary position: while acknowledging the absence of RCT data, they note that (a) such trials are unlikely to be conducted, (b) observational data from registries show temporal associations between dental procedures and IE, (c) the intervention is low-risk and inexpensive, and (d) the consequences of IE in prosthetic valve patients are catastrophic. Australian clinicians should follow ESC-aligned local guidelines but be aware of the NICE position for medico-legal and patient-education purposes.

Practical Implications for Australian Clinicians

Document the cardiac condition, the planned procedure, and the rationale for (or against) AP in the clinical record.
For patients who have been advised by UK-trained clinicians that AP is unnecessary, re-discuss with the patient and their cardiologist, applying the ESC-aligned Australian position.
For patients at moderate risk (e.g., bicuspid aortic valve with regurgitation, prior RHD) not classified as "high risk" by ESC, individualise the decision and document shared decision-making.
Maintain a register of patients requiring AP (e.g., in the practice management software) and alert them before dental appointments.

Aboriginal and Torres Strait Islander Health Considerations

Aboriginal and Torres Strait Islander Health

RHD burden

Aboriginal and Torres Strait Islander peoples experience the highest rates of rheumatic heart disease (RHD) in Australia, with notification rates up to 20 times the non-Indigenous rate in some remote communities. RHD-associated IE remains a major source of morbidity and mortality. Patients with established RHD should be assessed for IE prophylaxis on an individual basis, even when their condition does not strictly meet ESC "highest risk" criteria.

Dental access

Limited access to dental services in remote and very remote communities is a significant barrier to the primary prevention strategy of oral hygiene and regular dental care. Mobile dental services and community-controlled health organisations (ACCHOs) play a critical role. When dental procedures are performed (often in batched outreach clinics), prophylaxis should be administered per guideline.

Antibiotic access

Amoxicillin and clindamycin are both PBS-listed and generally available through community pharmacies and remote area nurses. In very remote settings, pre-positioned prophylactic doses should be maintained at the point of care. Ensure cold-chain integrity for reconstituted clindamycin suspension in paeds patients.

Cultural safety

Discuss prophylaxis in the context of the patient's understanding of RHD and its complications. Use culturally appropriate resources (e.g., RHDAustralia patient information in local language where available). Involve Aboriginal Health Workers and Practitioners in education and follow-up. Recognise that historical distrust of healthcare systems may affect adherence to prophylactic regimens.

Prosthetic valve considerations

Aboriginal and Torres Strait Islander patients who undergo valve surgery (often for severe RHD) and receive prosthetic valves are classified as highest risk for IE and require lifelong AP for eligible procedures. Ensure the surgical team communicates the AP indication clearly to the primary care team and the patient.

Health system navigation

Coordination between cardiologists, dental services, ACCHOs, and remote GPs is essential. Use the RHD register (where available) and My Health Record to flag AP requirements. Support patients in attending dental appointments through Patient-Assisted Travel Scheme (PATS) funding and transport coordination.

Monitoring & Follow-Up

While IE prophylaxis is a single-dose intervention, ongoing monitoring and health-system supports are essential to prevent missed prophylaxis and to detect IE early if it occurs.

1

Patient education

Educate all high-risk patients about symptoms of IE: fever, night sweats, new or changing heart murmur, unexplained embolic phenomena (stroke, splinter haemorrhages, Janeway lesions, Osler nodes). Provide written information (Heart Foundation or RHDAustralia fact sheets).

2

Dental care register

Maintain a practice-level or health-system register of patients requiring AP. Flag prosthetic valve, prior IE, and cyanotic CHD patients in the clinical record. Alert dental providers before procedures.

3

Cardiology review

Annual cardiology review for prosthetic valve patients includes echocardiography and assessment of valve function. Reassess AP indication if cardiac condition changes (e.g., successful repair of cyanotic CHD >6 months prior).

4

Post-procedure observation

No specific post-procedure observation period is mandated for uncomplicated dental AP. Instruct patients to seek medical attention if fever, rigors, or new cardiac symptoms develop within 2–4 weeks of any procedure.

5

Antimicrobial stewardship

IE prophylaxis should be prescribed as a single dose only — do not issue repeat scripts or "just in case" courses. Document the indication clearly to support antimicrobial stewardship audits.

Special Populations

🤰 Pregnancy

Amoxicillin 2 g PO — safe in pregnancy; no dose adjustment required. Category A (TGA).

Clindamycin 600 mg PO — category A; suitable alternative if penicillin allergy.

Cefazolin 1 g IV — category B1; safe if non-anaphylactic penicillin allergy and IV access required.

Pregnant women with prosthetic valves or prior IE require AP for eligible procedures at any gestation. Avoid tetracyclines (not part of standard regimens).

👶 Paediatric

Amoxicillin 50 mg/kg PO (max 2 g) — weight-based dosing; use suspension for young children.

Clindamycin 20 mg/kg PO (max 600 mg) — if penicillin allergy.

Children with unrepaired cyanotic CHD, prosthetic material, or prior IE are the primary paediatric target group. Neonates and infants requiring dental procedures (rare) should use weight-based dosing.

🫘 Renal Impairment

Amoxicillin — CrCl <30 mL/min: reduce to 1 g single dose (adult). CrCl <10 mL/min: avoid or use 500 mg.

Clindamycin — No significant renal adjustment required for single dose; hepatically metabolised.

Haemodialysis patients with prosthetic valves are at particularly high risk for S. aureus IE and should receive prophylaxis for eligible procedures.

🫁 Hepatic Impairment

Amoxicillin — No hepatic adjustment; safe in hepatic impairment.

Clindamycin — Hepatically metabolised; use with caution in severe liver disease. Single dose generally safe but monitor for GI side effects.

Prefer amoxicillin over clindamycin in significant hepatic impairment.

🛡️ Immunocompromised

Standard regimens apply — AP is not altered by immunosuppression per se; the indication is driven by the cardiac condition.

Cardiac transplant recipients who develop valvulopathy are classified as high-risk per ESC. Immunosuppressed patients may have atypical IE presentations; maintain a low threshold for investigation if post-procedure symptoms arise.

📚 References

1. Habib G, Lancellotti P, Antunes MJ, et al. 2015 ESC guidelines for the management of infective endocarditis. European Heart Journal. 2015;36(44):3075–3128. doi:10.1093/eurheartj/ehv319
2. National Institute for Health and Care Excellence. Prophylaxis against infective endocarditis: antimicrobial prophylaxis against infective endocarditis in adults and children undergoing interventional procedures. NICE guideline CG64. 2008 (updated 2016).
3. National Heart Foundation of Australia. Position statement: antibiotic prophylaxis for infective endocarditis. Heart Foundation; 2022.
4. Heart Foundation, Cardiac Society of Australia and New Zealand. Diagnosis and management of endocarditis: Australian expert commentary on ESC 2015 guidelines. Heart, Lung and Circulation. 2016;25(7):643–648.
5. Australian Institute of Health and Welfare. Rheumatic heart disease and acute rheumatic fever in Australia. AIHW Cat. No. CVD 86. Canberra: AIHW; 2023.
6. RHDAustralia (ARF/RHD writing group). The 2020 Australian guideline for prevention, diagnosis, and management of acute rheumatic fever and rheumatic heart disease (3rd edition). Menzies School of Health Research; 2020.
7. Cahill TJ, Harrison JL, Jewell P, et al. Antibiotic prophylaxis for infective endocarditis: a systematic review and meta-analysis. Heart. 2017;103(12):937–944. doi:10.1136/heartjnl-2015-309102
8. Dayer MJ, Jones S, Prendergast B, Baddour LM, Lockhart PB, Thornhill MH. Incidence of infective endocarditis in England, 2000–13: a secular trend, interrupted time-series analysis. Lancet. 2015;385(9974):1219–1228. doi:10.1016/S0140-6736(14)62007-9
9. Thornhill MH, Dayer MJ, Lockhart PB, et al. Guidelines on prophylaxis to prevent infective endocarditis. British Dental Journal. 2017;223(2):80–84. doi:10.1038/sj.bdj.2017.628
10. Antimicrobial Expert Advisory Committee. Therapeutic guidelines: antibiotic. Version 17. Melbourne: Therapeutic Guidelines Limited; 2024. [Referenced for prescribing alignment; not cited as standalone guideline.]
11. Ferrieri P, Gewitz MH, Gerber MA, et al. Unique features of infective endocarditis in childhood. Circulation. 2002;105(17):2115–2126. doi:10.1161/01.CIR.0000016344.93228.EE
12. Patient safety alerts on antibiotic prophylaxis. Australian Commission on Safety and Quality in Health Care (ACSQHC). National Safety and Quality Health Service Standards. Sydney: ACSQHC; 2021.