Antibiotics for a tooth infection, such as amoxicillin, penicillin V potassium, amoxicillin-clavulanate, clindamycin, or metronidazole, may be prescribed when a bacterial infection spreads from the tooth to nearby tissues. These medicines can help control bacterial growth, reduce the risk of progression, and treat infections associated with swelling, fever, malaise, or abscess formation.

However, antibiotics are not needed for most tooth pain or dental infections when dental treatment can be performed promptly. Treatment such as drainage, root canal, pulpotomy, or tooth extraction is usually the main way to control the source of infection.

Antibiotics should only be used when prescribed by a dentist or doctor, as unnecessary use can increase the risk of side effects and antibiotic resistance. The shortest effective course is generally preferred, and antibiotics may be stopped 24 hours after symptoms resolve when advised by the prescribing clinician.

List of antibiotics

Antibiotics that your dentist or doctor may prescribe for a tooth infection include:

1. Amoxicillin

Amoxicillin is usually considered the first-line antibiotic for most tooth infections in adults who are not allergic to penicillin. It is commonly used because it acts against many bacteria found in odontogenic infections, including oral streptococci and anaerobes.

Dosing: Adults may be prescribed 500 mg by mouth 3 times per day for 3 to 7 days, when antibiotics are truly needed and immediate dental care is not available.

Side effects: Digestive symptoms may occur, such as nausea, vomiting, diarrhea, or stomach discomfort.

Contraindications: Amoxicillin should not be used by people with a known allergy to penicillin, and caution may be needed in people with a history of severe beta-lactam reactions.

2. Penicillin V potassium

Penicillin V potassium, also called penicillin VK, is another first-line option for tooth infections, especially endodontic infections. It may be prescribed when systemic antibiotics are indicated and is considered an alternative to amoxicillin.

Dosing: Adults may be prescribed 500 mg by mouth 4 times per day for 3 to 7 days, depending on the infection and clinical response.

Side effects: Digestive symptoms may occur, such as nausea, vomiting, diarrhea, or abdominal discomfort.

Contraindications: Penicillin VK should not be used by people with a known allergy to penicillin or a history of severe allergic reaction to beta-lactam antibiotics.

3. Amoxicillin-clavulanate

Amoxicillin-clavulanate may be prescribed when broader antibiotic coverage is needed, especially if beta-lactamase-producing bacteria are suspected. It is also commonly considered when the infection is spreading, when risk factors are present, or when treatment with amoxicillin alone has not worked.

Dosing: The exact dose should be determined by the dentist or doctor, and treatment should be limited to the shortest effective duration, commonly 3 to 7 days when indicated.

Side effects: Digestive symptoms may occur, such as nausea, vomiting, diarrhea, or stomach discomfort.

Contraindications: Amoxicillin-clavulanate should not be used by people with a known allergy to penicillin, and caution is needed in people with previous severe beta-lactam reactions.

4. Clindamycin

Clindamycin may be prescribed for tooth infections in people who are allergic to penicillin, or in some severe infections or cases where first-line treatment has failed. It can penetrate bone and abscesses and provides activity against anaerobic bacteria involved in odontogenic infections.

Dosing: The exact dose should be prescribed by the dentist or doctor, and treatment should be limited to the shortest effective course based on symptoms and infection severity.

Side effects: Clindamycin can cause digestive symptoms and has a higher risk of serious adverse events, including Clostridioides difficile infection.

Contraindications: Clindamycin should not be used by people with a known allergy to clindamycin, and extra caution is needed in people with a history of serious antibiotic-associated diarrhea or C. difficile infection.

5. Metronidazole

Metronidazole may be used for tooth infections with significant anaerobic bacterial involvement. It is often used together with a beta-lactam antibiotic, such as amoxicillin, rather than being used alone.

Dosing: The exact dose should be determined by the dentist or doctor, and it is generally used as an adjunct when broader anaerobic coverage is needed.

Side effects: Digestive symptoms may occur, such as nausea, vomiting, diarrhea, stomach discomfort, or a metallic taste.

Contraindications: Metronidazole should not be used by people with a known allergy to this medicine, and it should only be used when specifically prescribed for the type of infection present.

6. Azithromycin

Azithromycin is a macrolide antibiotic that may be used selectively in people who cannot take beta-lactam antibiotics or clindamycin. It is not usually a first-line option for tooth infections because of resistance concerns and its more limited role in odontogenic infections.

Dosing: The exact dose should be prescribed by the dentist or doctor, and it should be used only when other options are unsuitable.

Side effects: Digestive symptoms may occur, such as nausea, vomiting, diarrhea, or stomach discomfort.

Contraindications: Azithromycin should not be used by people with a known allergy to macrolide antibiotics, and it should be used cautiously because of resistance concerns.

7. Cephalexin

Cephalexin is a cephalosporin antibiotic that may be considered in selected cases when a beta-lactam is desired but penicillin is being avoided. It is a less common option for tooth infections and should be used only after careful assessment of allergy risk.

Dosing: The exact dose should be prescribed by the dentist or doctor, and duration should be limited to the shortest effective course when antibiotics are indicated.