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Guide For Antibiotics Before Dental Work

Antibiotic prophylaxis (premedication) is required for dental procedures that induce bleeding if you've certain health conditions. If you need it, it is important to take it because there are medical consequences for not doing so.


Amoxicillin antibiotic
Amoxicillin antibiotic

Our purpose here today is to provide clarity for what is customarily meant to be done. All of the information provided will be based on the guidelines from the American Heart Association (AHA) and the American Dental Association (ADA).


Table of Contents:


How to premedicate for dental procedures

Antibiotics for prophylaxis should be orally taken 30-60 minutes before your dental procedure. Which one you take and how much of it will depend on if you're allergic to penicillin or not. Whether you're an adult or child will also affect it.


Antibiotic

Adults

Children

Amoxicillin

2 g

50 mg/kg

Azithromycin

500 mg

15 mg/kg

Cephalexin

2 g

50 mg/kg

Doxycycline

100 mg

if < 45 kg, then 2.2 mg/kg;


if > 45 kg, then 100mg

Clindamycin

600 mg

20 mg/kg


How to premedicate:

  1. Take antibiotic 30-60 mins prior to dental appointment.

  2. Try to have a meal or snack with the medication to prevent upset stomach.

  3. Go to your appointment and inform your dentist, you've complied with protocol.


Most commonly in dental settings, the default antibiotic to premedicate with is Amoxicillin.


Premedication with Penicillin allergy:

  • Do not take amoxicillin.

  • Take azithromycin or doxycycline instead.


Premedication with Penicillin allergy WITH heart condition:

  • Do not take amoxicillin

  • Do not take clindamycin or azithromycin.

  • Take doxycycline instead.


Cephalexin can also be safely taken for those with a penicillin allergy. Initial studies quoted a 10% cross-allergy risk with penicillin but recent research found it to be much lower. A 2012 study in the Journal of Emergency Medicine found the number closer to 1%. Due to the extremely low chance of an adverse reaction, it is considered a safe and valid alternative.


Clindamycin NOT recommended

In the past, dentists prescribed clindamycin as the antibiotic of choice for those with penicillin allergies. However, based on findings in a 2015 study done in the UK, there were far too many complications (some were even fatal) with using it.


  • Adverse drug reaction rate for amoxicillin was 0 fatal reactions per million RX.

  • Clindamycin had 13 fatal and 149 non-fatal reactions per million RX.

  • Most of the adverse drug reactions from clindamycin were Clostridium difficile infections.


Due to the overwhelming adverse reactions from using clindamycin as an antibiotic prophylaxis, it has now been removed from the 2021 guidelines by the AHA.


In other words, you're NOT supposed to take clindamycin if you're allergic to penicillin and you need dental work done. In lieu of it, the next best choice seems to be azithromycin.


Exception

Azithromycin may be the preferred choice in lieu of clindamycin but studies have shown that it should be used with caution in those with heart conditions.


A study found that patients with a prolonged QTc interval of >450 milliseconds as detected by ECG are at risk of a serious cardiac event. The recommendation is to use doxycyline instead.


What if I forgot to take it?

If you forgot to take your antibiotics 30-60 minutes before your dental procedure, you can still take it immediately before treatment. Alternatively, the guidelines also state that you may still take it even up to two hours after your procedure.


What to do for missed dose:

  • Take it right before your dentist starts the procedure.

  • Or take it up to 2 hours after finishing your dental treatment.

You should still be safe if you do either of the two if you inadvertently forgot to take it!


 

Who should premedicate?

The AHA and ADA have identified four groups of medical conditions that may have a high risk for an adverse outcome, viridans group streptococcal (VGS) infective endocarditis (IE).

  • Group 1: Prosthetic cardiac valve or prosthetic material used for cardiac valve repair or other implantable cardiac devices (e.g. transcatheter aortic valve implantation)

  • Group 2: Previous, relapse, or recurrent IE

  • Group 3: Congenital heart disease (CHD)

  • Group 4: Cardiac transplant recipients


The AHA also has a convenient printable wallet card for patients on preventing IE.


Prosthetic cardiac valves and material

  • Presence of prosthetic cardiac valves

  • Transcatheter implantation of prosthetic valves

  • Homografts

  • Cardiac valve repair devices (annuloplasty rings, chords, clips)

  • Left ventricular assist devices or implantable heart


Previous, relapse, or recurrent IE

  • History of infective endocarditis


Congenital heart disease

Congenital meaning these conditions were present since birth.

  • Unrepaired cyanotic CHD (palliative shunts and conduits)

  • Completely repaired cyanotic heart defect (within first 6 months)

  • Repaired CHD with residual defects at the site or near prosthetic patch/device

  • Surgical or transcatheter pulmonary artery valve or conduit placement (Melody valve and Contegra conduit)


Cardiac transplant recipients

Risk for infective endocarditis is the highest during the first six months of transplant. Research data is limited but they're typically immunosuppressed.

  • Heart transplant with valve regurgitation from a structurally abnormal valve


Reasons for increased risk:

  • Endothelial disruption

  • High-intensity immunosuppressive therapy

  • Frequent central venous catheter access

  • Frequent endomyocardial biopsies


Conditions where premedication is not recommended

  • Implantable electronic devices (pacemaker)

  • Septal defect closure devices (complete closure achieved)

  • Peripheral vascular grafts and patches (used for hemodialysis)

  • Coronary artery stents or other vascular stents

  • Mitral valve prolapse

  • CNS ventriculoatrial shunts

  • Vena cava filters

  • Pledgets


 

What does antibiotic prophylaxis prevent?

Premedicating with antibiotics for dental procedures is primarily meant to prevent infective endocarditis. However, it can also be used to prevent prosthetic joint infections but the guidelines have been recommending against this.


Infective endocarditis

The primary purpose of taking antibiotics prophylactically before dental procedures is to prevent infective endocarditis by viridans group streptococcal.


IE is defined as the inflammation of the inner heart linings as well as the valves which separate the four heart chambers. It is primarily caused by bacteria and can have a wide range of consequences.


Complications from infection:


That translates to a mortality rate of about 30% in 30 days. Older studies pegged the death rate at 38% which was even more. To put it concisely, you have a substantial chance of dying if you get this infection.


Prosthetic joint infections

Having a prosthetic joint used to be an indication for taking antibiotics before high risk dental procedures. However, according to the most recent ADA clinical practice guidelines in 2015, it is no longer recommended to premedicate for procedures.


management of prosthetic joint infections - ADA chairside guide

Essentially, the benefits do not outweigh the risks:

  • Studies found no association between dental procedures and prosthetic joint infections.

  • However, for severely immunocompromised patients, the orthopedic surgeon may still advise dental antibiotic prophylaxis.


We still have a lot of patients come in thinking that they need to premedicate before their appointment. The main issue with that is a lack of awareness because the patients are used to premedicating and now they're being told they don't need to.


When is premedication necessary?

Antibiotic premedication is recommended for all dental procedures that manipulate the gingival tissue, periapical region of the teeth, or perforations of the oral mucosa.


Affected dental procedures:


Which procedures don't need it?

Non-invasive procedures such as quick follow ups or limited oral examinations will not require it. Essentially anything that does not manipulate the gum tissue and cause bleeding.


Examples:

  • Denture adjustment

  • Inserting night guards

  • Changing out Invisalign trays

  • Vitality testing (cold testing or electric pulp testing)


Where can I get antibiotics for prophylaxis?

Prophylactic antibiotics are available by prescription only meaning you need a healthcare professional (dentist or physician) to prescribe it.


Who can prescribe it:

  • Dentist. You can ask your dentist to prescribe it and they often do as long as they have your medical history on record stating the need for it.

  • Physician. If the dentist you're seeing is new, you may want to ask your physician for the prescription. It avoids a lot of paperwork and backforth since you're already established at your physician's office but not at the new dentist's office.


Please do not try to buy it from a third party without a legitimate prescription.


Why is dental antibiotic prophylaxis important?

Our dentists in Long Island City have put together this guide to provide clarity as to when you should be taking antibiotic premedication and when you shouldn't. A lot of people are often not up to date with the guidelines due to its periodic changes.


Overall, all of this is important information to know because it affects your health. Infective endocarditis has a high mortality rate and you don't want to end up with it from a dental appointment.

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About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

Association Memberships:

Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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