From the FDA Drug Label
Amoxicillin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections: Gram-Positive Bacteria Enterococcus faecalis Staphylococcus spp. Streptococcus pneumoniae Streptococcus spp (alpha and beta-hemolytic) Gram-Negative Bacteria Escherichia coli Haemophilus influenzae Helicobacter pylori Proteus mirabilis
The best initial antibiotic for a toothache suspected to be of bacterial origin is amoxicillin 1.
- Key points:
- Amoxicillin has a broad spectrum of bactericidal activity against many Gram-positive and Gram-negative microorganisms.
- It is effective against common bacteria that cause toothaches, such as Streptococcus spp.
- However, the choice of antibiotic should always be based on the specific circumstances of the patient and the suspected causative organisms. Note: Clindamycin 2 is also an option, but it is typically reserved for penicillin-allergic patients or other patients for whom a penicillin is inappropriate.
From the Research
Amoxicillin is typically the best initial antibiotic for a bacterial toothache, prescribed at 500 mg three times daily for 7-10 days. For patients with penicillin allergies, clindamycin (300 mg four times daily for 7 days) is an appropriate alternative 3. These antibiotics are effective because dental infections are usually caused by a mixture of aerobic and anaerobic bacteria, and amoxicillin provides good coverage against the common oral pathogens.
Some key points to consider when prescribing antibiotics for a toothache include:
- The most recent study on antibiotic therapy in dentistry recommends amoxicillin as the first-line treatment for odontogenic infections 3
- Clindamycin is a suitable alternative for patients with penicillin allergies, but it may have a higher risk of gastrointestinal side effects 4
- Metronidazole is effective against anaerobic bacteria, but it is not recommended as a first-line treatment for toothaches due to its limited coverage against aerobic bacteria 5
- Antibiotics should always be used alongside appropriate dental treatment, as they alone cannot resolve the underlying cause of the infection
Adding clavulanic acid (Augmentin) may be necessary for more severe infections or if there's concern about beta-lactamase producing bacteria. Pain management with acetaminophen or ibuprofen and warm salt water rinses can help manage symptoms while the antibiotics take effect. Patients should seek prompt dental care even when starting antibiotics, as procedures like drainage, root canal, or tooth extraction are often necessary to completely resolve the infection.