What are the treatment options for dental infections in patients with a penicillin (PCN) allergy?

From the Guidelines

For patients with dental infections who have a penicillin allergy, the recommended alternative antibiotic options include cephalexin (2 g orally), clindamycin (600 mg orally), or azithromycin (500 mg orally), as outlined in the American Heart Association guidelines 1. When considering treatment for dental infections in patients with a penicillin allergy, it is crucial to select an antibiotic that provides adequate coverage against the common oral pathogens, including streptococci and oral anaerobes.

• The choice of antibiotic should be based on the severity of the infection and the patient's allergy history.
• For patients with a history of anaphylaxis, angioedema, or urticaria after treatment with any form of penicillin, cephalosporins should be avoided due to the risk of cross-reactions 1.
• Clindamycin is a suitable option for patients with a penicillin allergy, as it has excellent oral bioavailability and good penetration into bone and dental tissues.
• Azithromycin is another alternative, which can be used in patients with a penicillin allergy, especially when the infection is mild to moderate.
• It is essential to note that the resistance rates of viridans group streptococci to various antibiotics are high, which may impact the effectiveness of prophylactic therapy for dental procedures 1.
• The American Heart Association guidelines recommend cephalexin, clindamycin, azithromycin, or clarithromycin as alternative options for patients with a penicillin allergy undergoing dental procedures 1.

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.

Anaerobes: Serious respiratory tract infections such as empyema, anaerobic pneumonitis, and lung abscess; serious skin and soft tissue infections; septicemia; intra- abdominal infections such as peritonitis and intra-abdominal abscess

To reduce the development of drug-resistant bacteria and maintain the effectiveness of clindamycin hydrochloride and other antibacterial drugs, clindamycin hydrochloride should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria

For patients with a pcn allergy, clindamycin can be used as a treatment option for dental infections caused by susceptible anaerobic bacteria, streptococci, pneumococci, and staphylococci.

• The physician should consider the nature of the infection and the suitability of less toxic alternatives before selecting clindamycin.
• Bacteriologic studies should be performed to determine the causative organisms and their susceptibility to clindamycin 2.

From the Research

Treatment Options for Dental Infections with PCN Allergy

• For patients with a reported penicillin allergy, it is essential to evaluate the allergy history to determine the risk of an allergic reaction 3.
• Patients with low-risk allergy histories can undergo a direct amoxicillin challenge, while those with moderate-risk histories can be evaluated with penicillin skin testing 3.
• The use of cephalosporins in penicillin-allergic patients is generally safe, with a low rate of cross-reactivity, especially with third- or fourth-generation cephalosporins 4.
• Clindamycin is often used as an alternative antibiotic for penicillin-allergic patients, but it may have a higher rate of treatment failure and resistance, especially in severe cases 5.

Antibiotic Selection

• The choice of antibiotic for penicillin-allergic patients should be based on a detailed history and allergy testing, followed by combination therapy if necessary 5.
• Third- or fourth-generation cephalosporins or cephalosporins with dissimilar side chains to the offending penicillin can be used with a negligible risk of cross-allergy 4.
• Alternative antibiotics, such as carbapenems and fluoroquinolones, may be used in patients with a documented penicillin or cephalosporin allergy, but their use should be guided by allergy assessment and local resistance patterns 6.

Considerations

• The prevalence of true penicillin allergy is lower than reported, with up to 95% of reported allergies not corresponding to a true allergy when tested 7.
• Having a penicillin allergy label can result in a 50% increased odds of surgical site infection due to the use of alternative antibiotics 7.
• Inpatient allergy assessment can improve optimal antibiotic therapy for patients with a documented penicillin or cephalosporin allergy 6.