Medically reviewed by Drugs.com. Last updated on Mar 26, 2022.
The Principen brand name has been discontinued in the U.S. If generic versions of this product have been approved by the FDA, there may be generic equivalents available.
Uses of Principen:
- It is used to treat bacterial infections.
What do I need to tell my doctor BEFORE I take Principen?
- If you are allergic to Principen (ampicillin capsules); any part of Principen (ampicillin capsules); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have mono.
This is not a list of all drugs or health problems that interact with Principen (ampicillin capsules).
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Principen (ampicillin capsules) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Principen?
- Tell all of your health care providers that you take Principen (ampicillin capsules). This includes your doctors, nurses, pharmacists, and dentists.
- Very bad and sometimes deadly allergic side effects have rarely happened. Talk with your doctor.
- This medicine may affect certain lab tests. Tell all of your health care providers and lab workers that you take Principen (ampicillin capsules).
- Have your blood work checked if you are on Principen (ampicillin capsules) for a long time. Talk with your doctor.
- If you have high blood sugar (diabetes) and test your urine glucose, talk with your doctor to find out which tests are best to use.
- Do not use longer than you have been told. A second infection may happen.
- Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.
How is this medicine (Principen) best taken?
Use Principen (ampicillin capsules) as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take at least 30 minutes before or 2 hours after a meal.
- Take with a full glass of water.
- Keep using Principen (ampicillin capsules) as you have been told by your doctor or other health care provider, even if you feel well.
What do I do if I miss a dose?
- Take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Fever, chills, or sore throat; any unexplained bruising or bleeding; or feeling very tired or weak.
- Black, hairy tongue.
- Mouth irritation or mouth sores.
- Diarrhea is common with antibiotics. Rarely, a severe form called C diff–associated diarrhea (CDAD) may happen. Sometimes, this has led to a deadly bowel problem (colitis). CDAD may happen during or a few months after taking antibiotics. Call your doctor right away if you have stomach pain, cramps, or very loose, watery, or bloody stools. Check with your doctor before treating diarrhea.
What are some other side effects of Principen?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Diarrhea, upset stomach, or throwing up.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
If OVERDOSE is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Principen?
- Store at room temperature in a dry place. Do not store in a bathroom.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
Consumer information use
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else's drugs.
- Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about Principen (ampicillin capsules), please talk with your doctor, nurse, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
More about Principen (ampicillin)
- Side effects
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Drug images
- Drug class: aminopenicillins
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Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.