Principen (Ampicillin)

(℞) Prescription Required - Ampicillin is the Generic Equivalent of Principen

    Principen (Ampicillin) Dosage and Side Effects

    PRINCIPEN is no longer on the market, your health care provider can prescribe generic ampicillin to treat infections such as pneumonia, bronchitis, urinary tract infections, meningitis, and typhoid fever.

    Dentists often prescribe ampicillin before a dental procedure for people who are at risk of endocarditis, an infection in the lining of the heart.

    Proper Use of this medication

    How much ampicillin your doctor prescribes and how long you take it depend on your age, your kidney function, and the type of bacteria causing your infection.

    Be sure to take the entire amount in your prescription. Finish all the medication, even if you're feeling better or the infection appears to be over. (Not feeling sick does not mean the infection is completely gone.)

    If you stop taking ampicillin before completing the entire prescribed amount, the infection could come back and may be even more difficult to treat than it was the first time.

    You should always take ampicillin one hour before or two hours after meals.

    Ampicillin Overdose

    If you suspect an overdose, you should contact a poison control center or emergency room immediately.

    Call 911 if someone has collapsed or is not breathing from a possible severe allergic reaction to ampicillin.

    Missed Dose of Ampicillin

    If you miss a dose of ampicillin, try to take it as soon as you remember.

    If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of the medication at the same time.

    Side Effects

    Common side effects of ampicillin include:

    • Diarrhea, nausea, and vomiting
    • Hives or rash
    • Swelling of the tongue
    • Thrush or yeast infection
    • Black, hairy tongue
    • High levels of eosinophils, a type of white blood cell

    Serious side effects of ampicillin include:

    • Anaphylaxis, a life-threatening allergic reaction in which your throat may close up, you have trouble breathing, and your skin breaks out in hives
    • C. difficile colitis, a bacterial infection causing a severe form of loose, watery diarrhea with an unusually foul smell
    • Life-threatening skin reaction called erythema multiforme (Stevens-Johnson syndrome)
    • Low level of red blood cells
    • Inability of bone marrow to make neutrophils, a type of white blood cell
    • Superinfection, an infection that occurs at the same time or after the original infection
    • Low levels of platelets, cells needed for blood clotting, or white blood cells
    • Skin peeling, possibly with redness

    Warnings and Precautions

    You should not take ampicillin if:

    • You're allergic to ampicillin, any penicillin antibiotic, or any other ingredient in the medication
    • You have infectious mononucleosis

    Talk to your doctor before taking ampicillin if you have:

    • Allergies to many things
    • Asthma or ever had asthma
    • Acute Lymphoid Leukemia (ALL), a type of cancer of the white blood cells
    • HIV/AIDS
    • Seizures
    • Kidney problems
    • Inflammation or an infection of the intestines caused by taking antibiotics recently

    Pregnancy and Ampicillin

    Ampicillin is an FDA Pregnancy Category B drug, meaning animal studies indicate there is no risk to a fetus, but there are no human studies showing it's safe for an unborn baby.

    Tell your doctor if you are pregnant or plan to become pregnant before taking this medication.

    Ampicillin is safe for mothers to take while breastfeeding. Still, tell your doctor know if you are breastfeeding or plan to breastfeed while taking it.

    Interactions with this medication

    It's always important to share with your doctor and pharmacist all of the medications you are taking. This includes your prescriptions medications, over-the-counter (OTC) drugs, vitamins, nutritional supplements (nutritional shakes, protein powders, etc.), herbal remedies, and any illegal or recreational drugs.

    You should not take ampicillin if you are taking Theracrys [BCG live (intravesical)].

    Medications that have serious interactions with ampicillin include the following:

    • Vivotif (live typhoid vaccine)
    • Warfarin (Jantoven, Coumadin)
    • Methotrexate (Trexall, Rasuvo, Otrexup)
    • Magnesium citrate (Citroma, Citrate of Magnesia)
    • Exenatide (Byetta, Bydureon)
    • Acid reflux drugs, such as like Prevacid (deslansoprazole), Prilosec (omeprazole), Nexium (esomeprazole), and Protonix (pantoprazole)
    • Tramadol, (Ultram, Ultracet)
    • Doxycycline (Vibramycin, Doryx)
    • Tiagabine (Gabitril)
    • Bupropion (Wellbutrin, Zyban, Forfivo XL)
    • Allopurinol (Zyloprim, Lopurin, Aloprim)

    Ampicillin and Alcohol

    Because there are no known interactions between ampicillin and alcohol, you need not avoid or limit drinking alcohol while taking ampicillin.

    Ampicillin and Grapefruit

    Grapefruit interacts with some antibiotics, but it's not clear whether this includes ampicillin. Be safe, and avoid eating grapefruit or drinking grapefruit juice while taking the medication.

    Other related products

    The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

    Back to top