2TheApex:  Penicillin VK 500mg, Disp. 30 Tabs Take 2 stat then 1 QID until gonePenicillin allergic Patient: Clindamycin 300mg, Disp. 30 Tabs Take 2 stat then 1 QID until gone If the patient taking Pen VK does not have a decrease in symptoms within 48 hours we add Metronidazole 500mg Disp. 30 tabs taken QID until gone.The reason for choosing Pen VK as the first line antibiotic lies in the fact that it will kill most bacteria in endodontic infections. It is also a very narrow spectrum antibiotic thus it has very low side effects.  Baumgartner recommended Pen VK after his research published in 2003. A medication that is well tolerated is more likely to be taken by the patient and the prescription completed. It is also cheap. Patient compliance should be considered.Ideally, antibiotics should be limited to patients with malaise, fever, lymph node involvement, a suppressed or compromised immune system, cellulitis or a spreading infection, or a rapid onset of severe infection. This supported by Matthews review of the literature.Removal of the infection by complete debridement of the root canal system is a priority. Incision for drainage is also considered for all moderate to severe infections with localized involvement.When prescribing any medications the medical history is considered. With a complicated medical history other antibiotics can always be considered.-Pic is of Alexander Fleming, who is credited with discovering penicillin in 1928.