Other Names: Amcap, Amcill, Omnipen, Penamp, Polycillin, Principen, Supen, Totacillin, others

Why is this drug prescribed?
Ampicillin is a penicillin-like antibiotic that eliminates bacteria that cause infections, including pneumonia, bronchitis, and infections of the ear, urinary tract and skin.

When should it be used?
Follow the instructions on your prescription label carefully, and ask us or your pharmacist to explain any part that you do not understand. Doses should be taken as far apart as possible throughout the day. For example, if your doctor tells you to take ampicillin four times a day, take a dose every six hours. If it is not possible to take the drug around the clock, take it at evenly spaced intervals between the time you wake up in the morning and the time you go to bed at night (for example, at 7 a.m., noon, 5 p.m., and 10 p.m.).

How should it be used?
Ampicillin comes in capsules, chewable tablets, liquid, and pediatric drops to be taken orally, and in injection form. We have chosen the form that is best for you, and your prescription label tells you how much to take at each dose. Ampicillin should be taken on an empty stomach, one hour before or two hours after meals. Capsules should be taken with a full glass of water. The liquid and pediatric drops should be shaken well before each use to mix the medication evenly. Use the bottle dropper to measure the dose of pediatric drops. You may obtain a specially marked measuring spoon from your pharmacist to be sure of an accurate dose of the liquid. Tablets should be crushed or chewed thoroughly before they are swallowed. Ask us or your pharmacist any questions you have about refilling your prescription.

What special instructions should I follow while using this drug?
Take all of the medication prescribed, even after the infection appears to have gone away. Failure to do so could allow the infection to return.

What should I do if I forget to take a dose?
Take the missed dose as soon as you remember it. Take any remaining doses for that day at evenly spaced intervals.

What side effects can this drug cause? What can I do about them?

  • Shortness of breath, wheezing, rash, itching, hives
    Contact us or go to a hospital immediately. You may need emergency treatment.
  • Diarrhea, nausea, vomiting
    Contact us if this problem is severe or lasts for more than two days.

What other precautions should I follow while using this drug?
Tell your doctor if you are breast-feeding because ampicillin can pass from a mother to her baby in the milk. If you are allergic to penicillins or have asthma, hay fever, allergies, or kidney disease, tell us before you take this medication. Consult us before using any other medication while taking ampicillin. Ampicillin may decrease the effectiveness of some birth-control pills, so ask us or your pharmacist if you should use another form of birth control. If you have used all of the medication prescribed but still have symptoms of the infection, contact your doctor. If your doctor tells you to stop taking ampicillin, throw away any unused medication. Ampicillin may lose its effectiveness over time and should not be saved to treat another infection.