Episode #350: The Controversy Surrounding Prophylaxis, with Tom Viola

the best practices show podcast Nov 01, 2021

Imagine causing an accident while trying to prevent said accident. That is where prophylaxis stands in dentistry. By prescribing them unnecessarily to prevent infections, it can actually create resistance and increase infection risk. But there are ways to prevent this! And Dr. Tom Viola returns with Kirk Behrendt to teach you everything you need to know about prophylaxis to help you prescribe them appropriately and effectively. For the best practices on being a steward for antibiotics, listen to Episode 350 of The Best Practices Show!

Main Takeaways:

Dentists are overprescribing unnecessary antibiotics.

Overuse of antibiotics can lead to resistance.

Antibiotics and antibacterials can have adverse effects.

Overusing clindamycin can increase the risk of C. diff infection.

For the average patient, there is no evidence that prophylaxis is necessary.

Guidelines for antibiotic prophylaxis are constantly evolving. 


“[Why prophylaxis is controversial] boils down to two main points. And the first one is, is antibiotic prophylaxis even necessary? If I have to ask that question, I have to ask a preview question to that. What the heck is prophylaxis and why is it necessary? Well, we know that there are certain vectors under which bacteria that normally reside in the mouth can end up causing trouble in other parts of the body. Obviously, one of the issues is infective endocarditis. That is where bacteria from the mouth have found a way into the endocardium and may cause issues that can ultimately lead to bad outcomes for our patients.” (3:41—4:23)

“Bacteria in the mouth can find a way to where we’ve had replacement joints, plates, knee replacements, hip replacements, and so on. And that can lead to joint replacement failure. These are pretty significant events in people’s lives and, certainly, we want to try everything we can in dentistry to avoid that from happening. So, one of the ways we avoid bacteria that normally resides in the mouth to find other places or other ways into the body cavities is to prophylax with antibiotics, to kill them before they have a chance to establish residence elsewhere. But it’s controversial because everybody knows that when you overuse an antibiotic, it increases the risk of infection.” (4:25—5:07)

“There is that whole aspect of antibiotic stewardship, which is, we should be the stewards. We should be the lookouts for making sure that antibiotics are used both effectively and efficiently, but also appropriately so we’re not overusing them and therefore causing resistance to occur.” (5:08—5:25)

“I can run down the list pretty easily, of antibiotics, that we normally use in dentistry. And that's the problem, in and of itself, is that we have a great arsenal of antibiotics that we use in dentistry, but unfortunately, it’s a very small arsenal. And they're not really all antibiotics. We use the term colloquially but, really, they're antibacterials.” (5:34—5:54)

“Penicillins are our favorite antibacterials. That would include penicillin VK and amoxicillin, specifically, in dentistry. And I'd be hard-pressed to find a general dentist and any dental specialist as well that hasn't prescribed amoxicillin at some point in their practice. And the reason for that is because it works, because it has great efficacy and great coverage against the bugs we find in the mouth. Now, the penicillins are bactericidal, which means that they destroy the cell wall and, therefore, they kill the bacteria. Which would sound great if you're treating virulent bacteria that you want to get rid of. But remember, they don't just kill the bad guys; they also kill the good guys. And that can lead to problems with things like opportunistic infections and even the potential for increasing the risk of bleeding in patients who are using drugs like Coumadin. So, they're great drugs, but they do have their adverse effects.” (5:59—6:57)

“The dark side to penicillin is that they're derived from a mold, which means that you could be allergic. And anaphylaxis is always a very real threat with penicillin.” (7:14—7:27)

“The next drug we almost always use in dentistry for patients who are penicillin allergic has been traditionally clindamycin. Now, clindamycin can be bacteriostatic or bactericidal, depending on the dose. Typically, we look at it as bacteriostatic. But the problem with clindamycin — and to be fair, any antibacterial that we use in dentistry can cause pseudomembranous colitis, which is C. diff related diarrhea, and so on. But clindamycin seems to cause it more. So, there's a higher frequency or a higher incidence of C. diff related complications in patients who take clindamycin versus all the other antibiotics we use in dentistry.” (7:29—8:18)

“If you take clindamycin as we normally prescribe it, depending on how many days you take it, you could foster the growth of C. diff in your gut, and that could lead to pseudomembranous colitis or breakdown of the membranous lining in the colon. And that can be bad things, overall. Not to mention the fact that you've got profuse, watery diarrhea, which has a very characteristic odor. Nobody wants C. diff related diarrhea. And if you have it, everybody around you knows it.” (8:23—8:54)

“What about if we overutilized the antibiotics that we have in dentistry to the point where, now, the bugs have become resistant? What do we do, then? Our arsenal is too small to take that chance.” (13:44—13:56)

“All of our organizations in dentistry and the Association of Orthopedic Surgeons themselves all say don't do it. Why are we prophylaxing for joint replacement infection when almost every bit of evidence we have suggests it doesn't work, that we should not be prophylaxing for joint replacement infection except for the cases where the patient is really immunocompromised? And it can do wonders for maybe that patient because of their status. But otherwise, for the average patient that we see in dentistry who’s had a joint replacement, prophylaxis is unnecessary. There's no proof that it works, and all it’s doing is increasing their chance of resistance against the commonly used antibiotics in dentistry.” (14:44—15:39)

“As a pharmacist, I have the luxury and the privilege of being able to speak to more than just dental groups. And so, I've spoken to some medical doctors and their groups, and even orthopedic surgeons, and I've gotten their take on it. And their take is, ‘Who the heck wants to get a second knee replacement on the same knee? Who the heck wants to get another hip replacement on the same hip? Nobody wants that. So, if there's a chance, even this much, the most remote chance that infection could cause joint replacement failure and lead to very poor outcomes for our patient if their joints have to be replaced yet again, why would we take that chance? Just give them the amoxicillin, and we’re done. No risk, or very little risk.’” (15:45—16:33)

“As the pharmacist, I can tell you this. If you stand your ground as the dental professional and say, ‘I'm not doing it. It’s not required. It’s never been proven to do anything. I'm not going to do it,’ and the orthopedic surgeon says, ‘Yeah, you're right. Forget about it. I don't think we should use prophylaxis,’ trust me, your patient will find a way to get that antibiotic. Why? Because they don't want to go through another replacement surgery either. So, they’ll get their general practitioner to write it. Heck, I've had people take the pills out of their kid’s bottle. They will find a way to get that antibiotic.” (18:08—18:46)

“The American Heart Association has still reinforced the concept that we should be providing prophylaxis to avoid infective endocarditis. So, it’s not the same as the joint replacement infection thing. This is something where the American Heart Association says we should be doing it — but they did change the guidelines. And this was May of this year. This is not a slight on the American Heart Association, so I hope they don't take this the wrong way. But, man, the word didn't really get out.” (19:58—20:23)

“To be fair here, even the American Heart Association says prophylaxis is only indicated for patients at the highest risk of infective endocarditis. So, we’re worried, still, about drug resistance and we’re worried that the benefits are outweighed by the risks. So, it’s only for the highest risk or the riskiest patients for infective endocarditis. (20:52—21:19)

“There are many docs out there who insist that they like clindamycin, that for the treatment of dental infection, especially if it involves osseous infection, clindamycin does a good job. But we’re not talking about treating an infection here. We’re talking about preventing infection, infective endocarditis. And so, these are the guidelines. One more time, that word, guideline, is merely that — it’s a guideline. So, do we still have docs out there who are prescribing clindamycin for penicillin allergic patients to avoid infective endocarditis? Yes. Maybe they didn't read the guideline. Maybe they don't want to follow the guideline. But in any event, we now have clear guidelines for the use of antibiotics, and they don't include clindamycin, necessarily, anymore for patients that are penicillin allergic.” (22:09—23:00)

“Let's not forget that there are other issues with antibiotics as well. For example, the supposed connection between prescribing an oral antibacterial for a patient who takes an oral contraceptive. The risk of pregnancy is there or is not there. Well, we really don't know. So, when my students ask me, ‘So, tell me, Viola, once and for all. Do antibiotics that we use in dentistry make oral contraceptives less effective?’ my answer is “nes.” As in, yes and no. As in, we don't really freaking know because maybe it’s hard to get subjects to volunteer for this study. You know, ‘Take these two pills together. Let's see if you get pregnant.’ I don't know. It just seems like it’s a very difficult conversation because we don't have enough data to really make that decision.” (24:00—24:44)


0:00 Introduction.

2:10 Dr. Viola’s background.

3:28 Why prophylaxis is so controversial.

5:26 Frequently prescribed antibiotics in dentistry.

13:57 Dr. Viola’s take on joint replacement.

19:39 American Heart Association guidelines.

23:01 The future of antibiotics in dentistry.

25:29 Last thoughts on prophylaxis.

27:09 More about Dr. Viola and contact information.

Reach Out to Dr. Viola:

Dr. Viola’s website: https://www.tomviola.com/

Dr. Viola’s podcasts: https://www.tomviola.com/category/podcasts/

Dr. Viola’s email: [email protected] 

Dr. Viola’s Facebook: https://www.facebook.com/tomviolarph  

Dr. Viola’s social media: @pharmacologydeclassified


“Are Dentists Prescribing Too Many Unnecessary Antibiotics?” by Dr. Viola: https://www.tomviola.com/are-dentists-prescribing-too-many-unnecessary-antibiotics/


With over 30 years of experience as a pharmacist, educator, speaker, and author, Tom Viola, R.Ph., C.C.P., has earned his reputation as the go-to specialist for delivering quality continuing education content through his informative, engaging presentations. Tom’s sellout programs provide an overview of the most prevalent oral and systemic diseases and the most frequently prescribed drugs used in their treatment. Special emphasis is given to dental considerations and strategies for effective patient care planning.

As a clinical educator, Tom is a member of the faculty of 12 dental professional degree programs and has received several awards for Outstanding Teacher of the Year. Tom instructs dental hygiene students and practice dental hygienists in pharmacology and local anesthesia in preparation for national board exams. As a published writer, Tom is well-known internationally for his contributions to several professional journals in the areas of pharmacology, pain management, and local anesthesia. In addition, Tom has served as a contributor, chapter author, and peer reviewer for several pharmacology textbooks. As a professional speaker, Tom has presented continuing education courses to dental professionals internationally since 2001. Meeting planners agree that Tom is their choice to educate audiences within this specialty.


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