• Ampicillin is an antibiotic in the class of drugs called penicillins. Ampicillin fights bacteria in your body.
• Ampicillin is used to treat many different types of infections, such as tonsillitis, pneumonia, bronchitis, urinary tract infections, gonorrhea, and infections of the intestines such as salmonella (food poisoning).
• Ampicillin may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about ampicillin?

• Take all of the ampicillin that has been prescribed for you even if you begin to feel better. Your symptoms may begin to improve before the infection is completely treated.
• Do not break, chew, open, or crush the capsules. Swallow them whole.
• Ampicillin may decrease the effectiveness of birth control pills. Use a second method of birth control while taking ampicillin to protect against pregnancy.

Who should not take ampicillin?

• If you have ever had an allergic reaction to another penicillin or to a cephalosporin, do not take ampicillin unless your doctor is aware of your allergy and monitors your therapy.
• Before taking this medication, tell your doctor if you have kidney disease, stomach or intestinal disease, or infectious mononucleosis. You may not be able to take ampicillin because of an increased risk of side effects.
• If you are a diabetic, some glucose urine tests may give false positive results while you are taking ampicillin.
• Ampicillin is in the FDA pregnancy category B. This means that it is unlikely to harm an unborn baby. Ampicillin is generally considered to be safe for use during pregnancy. Do not, however, take this medication without first talking to your doctor if you are pregnant.
• Do not take this medication without first talking to your doctor if you are breast-feeding a baby.

How should I take ampicillin?

• Take ampicillin exactly as directed by your doctor. If you do not understand the instructions, ask your nurse, doctor, or pharmacist to explain them to you.
• Take each dose with a full glass of water.
• Take ampicillin on an empty stomach 1 hour before or 2 hours after meals.
• Ampicillin should be taken at evenly spaced intervals throughout the day and night to keep the level in your blood high enough to treat the infection.
• Do not crush, chew, or open the ampicillin capsules. Swallow them whole.
• ake all of the ampicillin that has been prescribed for you even if you begin to feel better. Your symptoms may start to improve before the infection is completely treated.
• Store the tablets and capsules at room temperature and store the suspension in the refrigerator for longer use.

What happens if I miss a dose?

• Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the dose you missed and take only your next regularly scheduled dose. Do not take a double dose of this medication unless otherwise directed by your doctor.
• If you have only missed one dose, you can take the rest of your scheduled doses for the day at evenly spaced intervals.

What happens if I overdose?

• Seek emergency medical attention.
• Symptoms of an ampicillin overdose include muscle spasms or weakness, pain or twitching, pain in the fingers or toes, loss of feeling in the fingers or toes, seizures, confusion, coma, and agitation.

What should I avoid while taking ampicillin?

• Alcohol may irritate your stomach if taken with ampicillin, so use it with moderation.

What are the possible side effects of ampicillin?

• If you experience any of the following serious side effects, stop taking ampicillin and seek emergency medical attention:
  • an allergic reaction (shortness of breath; closing of your throat; hives; swelling of your lips, face, or tongue; rash; or fainting);
  • seizures;
  • severe watery diarrhea and abdominal cramps; or
  • unusual bleeding or bruising.
• Other, less serious side effects may be more likely to occur. Continue to take ampicillin and talk to your doctor if you experience
  • mild nausea, vomiting, diarrhea, or abdominal pain;
  • white patches on the tongue (thrush/ yeast infection);
  • itching or discharge of the vagina (vaginal yeast infection); or
  • black, "hairy" tongue or sore mouth or tongue.
• Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What drug(s) may interact with ampicillin?

• allopurinol
• certain antibiotics given by injection
• clavulanic acid
• entacapone
• female hormones, including contraceptive or birth control pills
• methotrexate
• probenecid