For patients who have repeated culture-positive episodes of streptococcal pharyngitis, current recommendations include treatment with amoxicillin(/clavulanate or clindamycin(. If the infectious agent is penicillin-sensitive and especially if the patient responds well to penicillin VK with each episode, would a longer course of penicillin be a more effective treatment?
---- MD
All group A streptococci are highly sensitive to penicillin. Therefore, when treatment failure occurs, it is not because of antibiotic resistance. Recurrent episodes of "strep throat" are often recurrences of viral pharyngitis in a patient who is a chronic pharyngeal carrier of streptococci. Penicillins are relatively poor at eradicating carriage, but clindamycin is effective more than 90% of the time.
Some authors believe that persistent or recurrent streptococcal infections represent a situation in which the presence of a co-pathogen capable of destroying penicillin or amoxicillin, such as Staphylococcus aureus, enables the streptococci to survive. They justify use of a broader-spectrum antibiotic on that basis. However, there is no convincing evidence to support this theory or the use of broader-spectrum agents.
---- Stanford T. Shulman, MD
Professor of Pediatrics
Feinberg School of Medicine
Northwestern University
Chief, Division of Infectious Diseases
Children's Memorial Hospital Chicago