Expert: Walter Hintz - 3/11/2008

Question
A patient with streptococcal sore throat takes penicillin for two days of a prescribed 10 day regimen. Because he feels better, he then saves the remaining penicillin for some other time. After three more days, he suffers a relapse of the sore throat. Discuss the probable cause of the relapse.

Answer
Hi Becky
Studies that it takes time for an antibiotic to completely get rid of a pathogen.  With strep 10 ten days is the usual time needed.  After two days (with this patient) all of the beta strep were not destroyed.  Another possibility is that there were penicillin resistant bacteria present.