Ask Your Pharmacist

January 20, 2017

I had a knee replacement 10 years ago and have always been prescribed an antibiotic by my dentist to take before having dental work. I just booked an appointment, and he told me it’s no longer necessary. Should I be concerned?


For years, patients with certain heart conditions as well as those with prosthetic joints have been prescribed antibiotics to take prior to dental procedures in order to decrease the risk of developing certain serious infections. However, recent guidelines published by both the American and Canadian Dental Associations are no longer recommending this treatment for some of these patients. Pharmacists have received many questions from concerned patients who are worried that they may not be properly covered when seeing their dentist without an antibiotic beforehand. This article will provide a bit of detail to help you understand the reasons behind this change.

During certain dental procedures, it is possible that bacteria present in the gums or oral mucosa can become dislodged and enter the bloodstream. This can occur during many routine procedures such as cleanings, extractions and biopsies. There is a risk that these bacteria can travel throughout the body and attach to prosthetic devices such as joints and heart valves, thus leading to infections. A single dose of antibiotics can be taken 30 minutes to an hour before the procedure in order to kill these bacteria before they can cause a problem.

National health organizations around the world are implementing programs aimed at optimizing the use of antibiotic medications in order to improve safety and treatment outcomes, decrease unnecessary costs and slow down the development of antibiotic resistance. There are concerns that bacterial resistance is developing faster than new antibiotics can be developed. Thousands of deaths every year in North America are attributed to infections that can no longer be treated by any antibiotic. As a result, many prescribing practices have been reviewed including use before dental visits and some guidelines have been adjusted according to the findings.

The Canadian Dental Association no longer recommends routine antibiotic use to prevent prosthetic joint infections for patients with total joint replacements or orthopaedic pins, plates or screws who are undergoing dental procedures. They believe that any benefits to such treatment are outweighed by antibiotic risks such as side effects, drug interactions, bacterial resistance and unnecessary cost. The American Dental Association is also no longer recommending this practice as well. 

Interestingly, the guidelines published by the American Academy of Orthopaedic Surgeons have not fully recommended against the practice, stating that the evidence is not strong in support of either giving or not giving the antibiotic before dental procedures. Indeed, many surgeons are still recommending their patients use prophylactic antibiotics, and their directions should be followed accordingly.

It is important to note that the Canadian and American Dental Associations fully support the guidelines in place for the prevention of bacterial endocarditis. Individuals with issues such as an artificial heart valve, a history of heart infections and certain serious heart conditions that they’ve had since birth need to use antibiotics before dental procedures as prescribed. Bacterial endocarditis can be life threatening, and all precautions must be taken to avoid this potential serious infection.

It is still common to be prescribed antibiotics by your dentist to be taken before procedures. If you question whether the practice is right for you, don’t hesitate to ask your dentist, orthopaedic surgeon or pharmacist. Every patient is different, and it is important to consider the individual factors that you have which may impact either your risk of taking an antibiotic or developing an infection.

Ryan Kennedy (BSc., Doctorate of Pharmacy, MBA) is a pharmacist/owner at Jean Coutu in Saint John. His opinions expressed in this newspaper are published for educational and informational purposes only and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment. Send your questions to