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Generic Name: ampicillin/sulbactam (AM-pi-SIL-in/sul-BAK-tam)
Brand Name: Unasyn

Unasyn is used for:

Treating infections caused by certain bacteria.

Unasyn is a penicillin antibiotic. It works by blocking the bacteria's cell wall growth, which kills the bacteria.

Do NOT use Unasyn if:

  • you are allergic to any ingredient in Unasyn, to any penicillin antibiotic (eg, amoxicillin), or to any other beta-lactam antibiotic (eg, cephalexin)
  • you have mononucleosis ("mono")
  • you have had liver problems or yellowing of the skin or eyes from taking this drug

Contact your doctor or health care provider right away if any of these apply to you.

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Before using Unasyn:

Some medical conditions may interact with Unasyn. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have had a severe allergic reaction (eg, severe rash, hives, difficulty breathing, dizziness) to a cephalosporin (eg, cephalexin) or other beta-lactam antibiotic (eg, imipenem)
  • if you have kidney problems

Some MEDICINES MAY INTERACT with Unasyn. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Tetracyclines (eg, doxycycline) because they may decrease Unasyn's effectiveness
  • Probenecid because it may increase the risk of Unasyn's side effects
  • Allopurinol because the risk of skin rash may be increased
  • Heparin because the risk of bleeding may be increased
  • Methotrexate because the risk of its side effects may be increased by Unasyn
  • Anticoagulants (eg, warfarin) because their effectiveness may be decreased or the risk of their side effects may be increased by Unasyn
  • Aminoglycosides (eg, gentamicin), birth control pills, or live oral typhoid vaccine because their effectiveness may be decreased by Unasyn

This may not be a complete list of all interactions that may occur. Ask your health care provider if Unasyn may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Unasyn:

Use Unasyn as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Unasyn is given as an injection at your doctor's office, hospital, or clinic. Contact your health care provider if you have any questions.
  • If you miss a dose of Unasyn, call your doctor to find out what to do.

Ask your health care provider any questions you may have about how to use Unasyn.

Important safety information:

  • Unasyn only works against bacteria; it does not treat viral infections (eg, the common cold).
  • Be sure to use Unasyn for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
  • Long-term or repeated use of Unasyn may cause a second infection. Your doctor may want to change your medicine to treat the second infection. Contact your doctor if signs of a second infection occur.
  • If vomiting or diarrhea occurs, you will need to take care not to become dehydrated. Contact your doctor for instructions.
  • Mild diarrhea is common with antibiotic use. However, a more serious form of diarrhea (pseudomembranous colitis) may rarely occur. This may develop while you use the antibiotic or within several months after you stop using it. Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
  • Serious and sometimes fatal liver problems have happened with Unasyn. Call your doctor right away if you have symptoms of liver problems (eg, dark urine; pale stools; persistent loss of appetite; unusual nausea, stomach pain, or tiredness; yellowing of the skin or eyes).
  • Serious and sometimes fatal allergic reactions have rarely happened. Talk with your doctor.
  • Hormonal birth control (eg, birth control pills) may not work as well while you are using Unasyn. To prevent pregnancy, use an extra form of birth control (eg, condoms).
  • Unasyn may interfere with certain lab tests. Be sure your doctor and lab personnel know you are using Unasyn.
  • Diabetes patients - Unasyn may cause the results of some tests for urine glucose to be wrong. Ask your doctor before you change your diet or the dose of your diabetes medicine.
  • PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Unasyn while you are pregnant. Unasyn is found in breast milk. If you are or will be breast-feeding while you use Unasyn, check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Unasyn:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Mild diarrhea; pain, swelling, or redness at injection site.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody stools or severe diarrhea; chest pain; chills; fever; severe nausea or vomiting; stomach pain or cramps; unusual bruising or bleeding; vaginal irritation or discharge; vein inflammation or tenderness; white patches in mouth.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately.

Proper storage of Unasyn:

Unasyn will be handled and stored by a health care provider. You will not store it at home. Keep all medicines out of the reach of children and away from pets.

General information:

  • If you have any questions about Unasyn, please talk with your doctor, pharmacist, or other health care provider.
  • Unasyn is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information should not be used to decide whether or not to take Unasyn or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Unasyn. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Unasyn. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your health care provider for complete information about the risks and benefits of using Unasyn.

Issue Date: June 3, 2015
Database Edition 15.2.1.003
Copyright © 2015 Clinical Drug Information, LLC

Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.

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