What antibiotic can be given post root canal with possible aspiration in a patient with an allergy to Amoxicillin (amoxicillin)?

From the FDA Drug Label

Clindamycin is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylocci Its use should be reserved for penicillin-allergic patients or other patients for whom, in the judgment of the physician, a penicillin is inappropriate.

Clindamycin can be given post root canal with possible aspiration in a patient with an allergy to Amoxicillin. This is because Clindamycin is indicated for use in penicillin-allergic patients, and it covers a range of bacteria that may be involved in a root canal infection, including anaerobes, streptococci, pneumococci, and staphylococci 1.

From the Research

For a patient with an amoxicillin allergy who needs antibiotics after a root canal with possible aspiration, clindamycin is the recommended alternative, as supported by the most recent study 2 which evaluated the susceptibility of endodontic pathogens to antibiotics. The typical dosage is 300 mg taken orally every 6 hours for 7 days. For more severe infections, 450 mg every 6 hours may be prescribed.

• Alternatively, azithromycin 500 mg on day one followed by 250 mg daily for 4 more days can be effective.
• If the patient has a severe penicillin allergy with anaphylaxis history, avoid cephalosporins as well due to potential cross-reactivity. These antibiotics work by inhibiting bacterial protein synthesis (clindamycin) or bacterial growth (azithromycin), effectively targeting the mixed aerobic and anaerobic bacteria commonly involved in dental infections, as identified in studies 2, 3. It's essential to complete the full course of antibiotics even if symptoms improve before finishing, and to seek immediate dental or medical attention if symptoms worsen, fever develops, or swelling increases, as this could indicate the infection is spreading. The choice of antibiotic should be based on the most recent and highest quality evidence, which in this case is the 2021 study 2 that evaluated the susceptibility of endodontic pathogens to antibiotics, including clindamycin and amoxicillin.
• Key points to consider when prescribing antibiotics for a patient with an amoxicillin allergy include:
  • The severity of the infection and the potential for aspiration
  • The patient's medical history, including any history of anaphylaxis or severe allergic reactions
  • The susceptibility of the endodontic pathogens to different antibiotics, as identified in studies 2, 3