Type to search

Oral Medicine

What is the most effective antibiotic therapy for an acute odontogenic infection?

(Content under development)

The following question was submitted by a practising dentist: What is the most effective antibiotic therapy for an acute odontogenic infection? If you ask the oral surgeons they say doxycycline , when you ask the infectious disease specialists they say amoxicillin. In the literature some papers state clindamycin and then others the combination of flagyl.

JCDA Editorial Consultant Dr. Mark Donaldson of Kalispell, Montana provided this initial response for consideration:

The correct antibiotic is the one that works! If we remember that the basic tenet of infectious diseases is to match the right drug to the right bug, then the choice is always a simple one.  However, in most cases we do not have the C&S  (culture and sensitivity) data until 24 hours after we swab the patient (or collect urine/blood/sputum)  and send the specimen to the lab, in which case we treat patients empirically, based on what we think is the likely pathogen.

Empirical prescribing of antibiotics is commonplace in dentistry since we are generally familiar with the most common pathogens.  For an acute odontogenic infection our differential based on prevalence is:

Streptococcus > Actinomyces, Eubacterium, Leptotrichia > Fusobacterium, Bacteroides, Prevotella, Porphyromonas > Peptostreptococcus >  Lactobacillus > Veillonella

For these reasons, antibiotics should be started as soon as possible after any mechanical intervention such as incision and drainage and the typical algorithm based on current evidence is:

First choice:

Amoxicillin 500mg orally three times a day

Second choice:

Augmentin 875mg orally twice a day*

Penicillin VK 500mg orally three times a day**

If penicillin allergic***:

Clindamycin 300mg orally three times a day

Azithromycin 500mg now then 250mg orally once a day (Z-pak)

* Consider Augmentin in place of Amoxicillin if methicillin resistant Staphylococcus aureus (MRSA) is either suspected or highly prevalent in the community.

** Penicillin is still or best single agent against Streptococcal infections (including Peptostreptococcus).  It has no activity against gram-negative infections, however.  Consider the addition of clindamycin for severe infections to improve this coverage.

*** Anytime a patient reports a history of anaphylaxis, angioedema or urticaria following penicillin, ampicillin or amoxicillin.

I was co-author on a pertinent article published in 2009:  Goodchild JH and Donaldson M. Appropriate antibiotic prescribing for the general dentist. General Dentistry 2009;57(6):627-634.

Some additional considerations for dentists prescribing antibiotics are attached.

JCDA Editorial Consultant Dr. Archie McNicol of the University of Manitoba also provided this initial response for consideration:

It will likely depend very much on how aggressive the infection is and the immunocompetence of the patient. For a relatively non-aggressive infections amoxicillin (or even penicillin V) would probably suffice (assuming no contraindications). For more severe infections the oral surgeons here complement this with metronidazole.

I would think that secondary therapy (eg penicillin allergies) tends to be a macrolide (eg erythromycin/clarithromycin/azithromycin), although these are much more dependent on immunocompetence. Clindamycin is probably reserved for situations when penicillin or the macrolide are ineffective, although the potential for GI adverse effects are significant.

Follow-up: Readers are invited to comment on this initial response and provide further insights by posting in the comment box which you will find by clicking on “Leave a reply“ below. Comments come directly to me for approval prior to posting. You are welcome to remain anonymous. We will never post your email address in any response. John


Leave a Comment

Your email address will not be published. Required fields are marked *