According to WebMD, penicillin is one of the prescription antibiotics that is effective for an abscessed tooth. Others include amoxicillin, erythromycin, clindamycin and metronidazole. Patients typically take the liquid or pill medication for seven to 10 days.
WebMD explains that bacterial infection and gum disease often cause abscesses. Pus collects in the tissues around or beneath the tooth. An abscess often responds to antibiotic treatment, but sometimes it is necessary to drain the infection. If the infection reaches the pulp, or living tissue, of the tooth, a root canal procedure removes the affected area. If this is not successful, the tooth must sometimes be extracted.