Will cephalexin (cephalexin) therapy for a dental infection also provide coverage for streptococcal pharyngitis (strep throat)?

From the Guidelines

Cephalexin is not the first-line treatment for strep throat, and its use should be limited to patients who are allergic to penicillin or have a specific indication for its use. When considering the treatment of strep throat, it's essential to prioritize the most effective and narrow-spectrum antibiotics to minimize the risk of resistance and side effects. According to the Infectious Diseases Society of America guidelines 1, penicillin and its congeners, such as ampicillin and amoxicillin, are the preferred treatments for strep throat due to their proven efficacy, safety, and narrow spectrum. Some key points to consider when treating strep throat include:

• The importance of completing a full 10-day course of antibiotics to achieve maximal rates of pharyngeal eradication of Group A Streptococcus (GAS) 1
• The potential for cephalosporins, such as cephalexin, to be used as an alternative in patients with penicillin allergy, but with caution due to the risk of cross-reactivity and the broader spectrum of activity 1
• The need to avoid broad-spectrum cephalosporins and other antibiotics with a high risk of resistance, such as tetracyclines, sulfonamides, and fluoroquinolones 1 In the context of treating a tooth infection, cephalexin may be a suitable option, but its use for strep throat should be approached with caution and only considered when other options are not available. It's crucial to consult with a healthcare provider to determine the best course of treatment for each individual case.

From the FDA Drug Label

Cephalexin is indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms: Respiratory tract infections caused by Streptococcus pneumoniae and Streptococcus pyogenes Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever Cephalexin is generally effective in the eradication of streptococci from the nasopharynx; however, substantial data establishing the efficacy of cephalexin in the subsequent prevention of rheumatic fever are not available at present.

Cephalexin may be effective against Streptococcus pyogenes, which is a common cause of strep throat. However, penicillin is the usual drug of choice for treating streptococcal infections, including strep throat.

• The use of cephalexin for strep throat should be based on culture and susceptibility tests to ensure the bacteria are susceptible to the drug.
• It is essential to note that cephalexin is not the first-line treatment for strep throat, and its effectiveness in preventing rheumatic fever is not well established 2.

From the Research

Cephalexin for Tooth Infection and Strep Throat

• Cephalexin is an antibiotic that can be used to treat bacterial infections, including tooth infections and strep throat 3.
• A study published in 1992 found that cephalexin was more effective than penicillin in treating group A beta-hemolytic streptococcal throat infections in children 3.
• However, another study published in 2021 found that there was no significant difference in symptom resolution between cephalosporins (including cephalexin) and penicillin in the treatment of group A beta-hemolytic streptococcal pharyngitis 4.
• The American Family Physician recommends using first-generation cephalosporins, such as cephalexin, as an alternative to penicillin for patients with non-anaphylactic allergies to penicillin 5.

Effectiveness of Cephalexin for Strep Throat

• The evidence suggests that cephalexin can be effective in treating strep throat, but its effectiveness compared to other antibiotics is still uncertain 4, 3.
• A study published in 2020 found that antibiotics with narrow spectrums of activity, such as cephalexin, are appropriate for treating strep throat 6.
• However, the same study noted that there is significant controversy regarding the best methods to diagnose and treat strep throat, and that more research is needed to determine the most effective treatment strategies 6.

Cephalexin for Tooth Infection

• Cephalexin can be used to treat tooth infections, including dentoalveolar infections 7.
• A systematic review published in 2021 found that cephalexin was one of several antibiotics used to manage dentoalveolar infections, and that the ideal choice and regimen of empirical oral antibiotics for these infections is unclear 7.
• The review suggested that narrow-spectrum agents, such as cephalexin, may be as effective as broad-spectrum antibiotics in treating dentoalveolar infections in otherwise healthy individuals 7.