Ampicillin is a penicillin-like antibiotic used to treat certain infections caused by bacteria such as pneumonia; bronchitis; and ear, lung, skin, and urinary tract infections.

Principen (Ampicillin) Directions:
Follow the directions for using this medicine provided by your doctor. TAKE THIS MEDICINE on an empty stomach 1 hour before or 2 hours after meals or snacks. STORE THIS MEDICINE at room temperature in a tightly-closed container, away from heat and light. TO CLEAR UP YOUR INFECTION COMPLETELY, continue taking this medicine for the full course of treatment even if you feel better in a few days. Do not miss any doses. IF YOU MISS A DOSE OF THIS MEDICINE, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Principen (Ampicillin) Cautions:
DO NOT TAKE THIS MEDICINE IF YOU HAVE HAD A SEVERE ALLERGIC REACTION to a penicillin antibiotic (such as amoxicillin, ampicillin) or a cephalosporin antibiotic (such as Ceclor, Keflex, Ceftin, Duricef). A severe reaction includes a severe rash, hives, breathing difficulties, or dizziness. If you have a question about whether you are allergic to this medicine, contact your doctor or pharmacist.

Principen (Ampicillin) Side Effects:
SIDE EFFECTS that may occur while taking this medication include upset stomach, diarrhea, vomiting and mild skin rash.