Ampicillin
Common brand names: Omnipen, Polycillin.
Description: Ampicillin is a member of the penicillin class of antibiotics and is classified as extended-spectrum, meaning it can kill a wider range of bacteria than penicillin VK. However, in most dental infections this is not considered an advantage, and can actually lead to more side effects.
Dental Uses: Ampicillin is used to treat tooth and endodontic infections and abscesses (especially those extending into the sinuses and gums), gum infections, and periodontal disease. The drug usually preferred for all the above, however, is an improved form of ampicillin called amoxicillin, which is better absorbed.
Dosages for dental purposes: The typical adult dose is 250 milligrams to 500 milligrams every six hours for seven to 10 days.
Concerns and possible side effects: Ampicillin causes a higher incidence of nausea, vomiting, diarrhea and yeast infections (in women) than penicillin VK. About 10 percent of individuals who ingest ampicillin develop a skin rash. Occasionally ampicillin causes ulcerations in the mouth. Ampicillin and other penicillins must not be used by people with documented allergies to these drugs. Allergic reactions can range from a mild rash to life-threatening closure of the airway and a fall in blood pressure.