Official reprint from UpToDate®
www.uptodate.com ©2018 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Patient education: Antibiotics before procedures (Beyond the Basics)

Daniel J Sexton, MD
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Elinor L Baron, MD, DTMH
0 Find synonyms

Find synonyms Find exact match



Many people are told that they need to take an antibiotic before having a dental, surgical, or other invasive medical procedure. This topic discusses the benefit of taking a preprocedure antibiotic, who should take antibiotics, and provides an explanation of when antibiotics are usually recommended.

Certain procedures, such as a root canal or tooth extraction (as discussed below), may allow bacteria from the mouth to enter the bloodstream. Rarely, these bacteria can infect the heart valves and lining of the heart, causing them to become inflamed. This inflammation is called infective endocarditis (IE). IE has the potential to cause catastrophic medical problems, including heart failure and leakage of the heart valves.

When taken before a procedure, antibiotics may prevent bacteria from being released into the bloodstream. This is known as antibiotic prophylaxis.

The guidelines provided below may not apply to every situation. There may be instances in which a person has a high or moderate risk of IE and antibiotics are not recommended. In such cases, it is important to understand the risks and benefits of taking versus not taking preventive antibiotics. You should discuss these issues with your healthcare provider before the procedure.


Infective endocarditis (IE) is an infection of the lining of heart chambers or valves with bacteria, fungi, or other organisms. IE occurs most commonly in people who have abnormal heart valves or had previous heart surgery; less commonly, it can occur in otherwise healthy people who have do not have heart disease. (See 'Guidelines for antibiotic prophylaxis' below.)

IE develops following a sequence of events:

Bacteria circulate in the bloodstream and stick to the lining or valves of the heart, usually at a site of previous injury or surface irregularity or abnormality.

The bacteria then grow on the valve surface, forming a small mass (called a vegetation) on the heart valves or lining. The valve or surface that is infected may then become secondarily damaged.

IE can develop in a very small percentage of people who undergo dental or other medical procedures that can cause bacteria to be transiently released into the bloodstream. Antibiotics are commonly given to people undergoing dental procedures who have preexisting heart murmurs or known problems with their heart valves, although the evidence that these antibiotics are always necessary or effective is not conclusive. Some studies show that antibiotics can help to prevent IE, while others show no benefit.

Guidelines for antibiotic prophylaxis — In the past, American Heart Association guidelines recommended that most patients with a heart murmur receive antibiotics prior to almost any dental procedure, even minor ones. However, these guidelines have changed considerably over time as more information has become available about the actual risk of dental procedures for patients with heart conditions. Review of studies performed between 1950 and 2006, which included thousands of patients, has shown that there was no benefit of using preventive antibiotics, except in the highest risk patients [1].

Highest risk — People with the following conditions are considered to be at the highest risk of developing IE. Preventive antibiotics are generally recommended for people with the following conditions before certain procedures:

A prosthetic heart valve

Valve repair with prosthetic material

A prior history of IE

Unrepaired cyanotic congenital heart disease, including palliative shunts and conduits

Completely repaired congenital heart defects with prosthetic material or device during the first six months after the procedure (whether placed by surgery or by catheter intervention)

Repaired congenital heart disease with residual defects at the site or adjacent to the site of the prosthetic patch or prosthetic device

Procedures that require pretreatment with antibiotics are listed below. (See 'Antibiotic recommendations' below.)

Moderate risk — People with the following conditions are considered to be at moderate risk of developing IE. Antibiotic prophylaxis is NOT generally recommended for people with moderate risk conditions. This is an important change from prior recommendations [1].

Valve repair without prosthetic material

Hypertrophic cardiomyopathy

Mitral valve prolapse with valvular regurgitation and/or valvular thickening

Most other congenital cardiac abnormalities not listed above

Unrepaired ventricular septal defect, unrepaired patent ductus arteriosus

Acquired valvular dysfunction (eg, mitral or aortic regurgitation or stenosis)

Low risk — People with the following conditions are thought to have a low risk of IE. Antibiotics have never been recommended for people with these conditions:

Physiologic, functional, or innocent heart murmurs

Mitral valve prolapse without regurgitation or valvular leaflet thickening

Mild tricuspid regurgitation

Coronary artery disease (including previous coronary artery bypass graft surgery)

Simple atrial septal defect

Atrial septal defect, ventricular septal defect, or patent ductus arteriosus that was successfully closed (either surgically or with a catheter-based procedure) more than six months previously

Previous rheumatic fever or Kawasaki disease without valvular dysfunction

People with pacemakers or defibrillators

Preventative antibiotics are recommended for high-risk patients (as outlined above) undergoing dental procedures that involve manipulation of the tissue of the gums, the periapical region of the teeth, or perforation of the lining membranes of the gums such as tooth extractions, routine dental cleaning (scaling), or drainage of a dental abscess.

Other procedures such as anesthetic injections, dental X-rays, placement of orthodontic or prosthodontics appliances, loss of baby teeth, or bleeding from trauma to the lips or cheeks do not require antibiotics even in high-risk patients.

Dental care recommendations — Anyone who is at risk of developing IE should follow a program of careful mouth and tooth care. This includes a professional cleaning every six months, twice-daily tooth brushing, and daily flossing. These measures can help to prevent plaque and bacteria from building up around the gums and teeth.


The following treatment suggestions come from the American Heart Association's guidelines on antibiotic prophylaxis.

Dental, oral, or upper respiratory tract procedures — People who are at highest risk for infective endocarditis (IE) (see 'Highest risk' above) should take one dose of an antibiotic by mouth (pills or liquid) one hour before certain dental, oral, or upper respiratory tract procedures; a second dose is not necessary.

People allergic to penicillin – People who are allergic to penicillin can be treated one hour before the procedure with an alternate antibiotic.

People unable to take oral medications – People who are unable to take oral medications can be treated with an antibiotic injection 30 minutes before the procedure.

Genitourinary or gastrointestinal procedures — The American Heart Association does not consider surgeries or procedures on the digestive or urinary system to have a high risk of causing IE. This includes colonoscopy, sigmoidoscopy, cystoscopy, and many other procedures.

Antibiotics are no longer routinely recommended before these procedures, even in people with the highest risk heart conditions [1].

Patients with prosthetic joints — Patients with prosthetic joints do not require antibiotic therapy prior to dental procedures. Although antibiotics were commonly given in the past in such circumstances, the American Academy of Oral Medicine, the American Dental Association, the American Academy of Orthopedic Surgery, and the British Society for Antimicrobial Chemotherapy all advise against the routine use of antibiotics prior to teeth cleaning, teeth scaling, or routine procedures such as filling of a dental cavity. However, active dental infections in patients with prosthetic joints should be treated promptly, and good oral hygiene should be maintained.

Patients with breast implants — There are no data to support administration of prophylactic antibiotics to women with prosthetic breast implants prior to dental procedures, and we do not recommend it.

Pregnancy — Pregnant women who are at highest risk for IE (see 'Highest risk' above) should take an antibiotic before certain dental, oral, or upper respiratory tract procedures.

A pregnant woman who has a high risk of IE does NOT usually need antibiotic prophylaxis before a normal vaginal delivery or cesarean section. Antibiotics may be recommended before labor or cesarean section for other reasons, including prevention of complications related to group B Streptococcus. (See "Patient education: Group B streptococcus and pregnancy (Beyond the Basics)".)

Children — Children with a moderate or high risk of developing IE are usually given antibiotics before selected dental and surgical procedures.


Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Mitral regurgitation (The Basics)
Patient education: Mitral valve prolapse (The Basics)

Patient education: Tetralogy of Fallot (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Group B streptococcus and pregnancy (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Antithrombotic therapy in patients with infective endocarditis
Antimicrobial prophylaxis for the prevention of bacterial endocarditis
Antimicrobial therapy of native valve endocarditis
Antimicrobial therapy of prosthetic valve endocarditis
Candida endocarditis and suppurative thrombophlebitis
Complications and outcome of infective endocarditis
Clinical manifestations of Staphylococcus aureus infection in adults
Epidemiology, microbiology, and diagnosis of culture-negative endocarditis
Clinical manifestations and evaluation of adults with suspected native valve endocarditis
Epidemiology, risk factors, and microbiology of infective endocarditis
Infections involving cardiac implantable electronic devices
Infective endocarditis in injection drug users
Pathogenesis of vegetation formation in infective endocarditis
Epidemiology, clinical manifestations, and diagnosis of prosthetic valve endocarditis
Role of echocardiography in infective endocarditis
Surgery for left-sided native valve infective endocarditis
Surgery for prosthetic valve endocarditis

The following organizations also provide reliable health information.

National Library of Medicine


National Heart, Lung, and Blood Institute


American Heart Association



Literature review current through: Dec 2017. | This topic last updated: Thu Mar 16 00:00:00 GMT 2017.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2018 UpToDate, Inc.

All topics are updated as new information becomes available. Our peer review process typically takes one to six weeks depending on the issue.