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Unasyn vs. Principen

Are Unasyn and Principen the Same Thing?

Unasyn (ampicillin sodium/sulbactam sodium) and Principen (ampicillin) are antibiotics used to treat bacterial infections.

Unasyn and Principen both contain penicillin-type antibiotics. Unasyn also contains a beta-lactamase inhibitor.

Side effects of Unasyn and Principen that are similar include headache, diarrhea, nausea, vomiting, stomach pain, vaginal itching or discharge, swollen/black/"hairy" tongue, and thrush (white patches inside your mouth or throat).

Side effects of Unasyn that are different from Principen include fever, sore throat, rash, body aches, bloating, gas, itching, and pain, swelling, or irritation where the needle is placed.

Side effects of Principen that are different from Unasyn include mouth/tongue sores.

Both Unasyn and Principen may interact with allopurinol.

Unasyn may also interact with probenecid.

Principen may also interact with methotrexate, sulfa drugs, or tetracycline antibiotics.

What Are Possible Side Effects of Unasyn?

Common side effects of Unasyn include:

  • fever,
  • sore throat,
  • headache,
  • rash,
  • diarrhea,
  • body aches,
  • nausea,
  • vomiting,
  • stomach pain,
  • bloating,
  • gas,
  • vaginal itching or discharge,
  • itching,
  • swollen/black/"hairy" tongue,
  • thrush (white patches inside your mouth or throat), or
  • pain, swelling, or irritation where the needle is placed.

What Are Possible Side Effects of Principen?

Common side effects of Principen include:

  • nausea,
  • vomiting,
  • stomach pain,
  • diarrhea,
  • vaginal itching or discharge,
  • headache,
  • mouth/tongue sores,
  • thrush (white patches inside your mouth or throat), or
  • swollen, black, or "hairy" tongue.

Tell your doctor if you have rare but very serious side effects of Principen including:

  • dark urine,
  • persistent nausea or vomiting,
  • yellowing eyes or skin,
  • easy bruising or bleeding, or
  • persistent sore throat or fever.

What Is Unasyn?

Unasyn (ampicillin sodium/sulbactam sodium) is a combination antibiotic indicated for the treatment of infections due to susceptible strains of microorganisms.

What Is Principen?

Principen (ampicillin) is a penicillin-type antibiotic used to treat many different types of infections caused by bacteria, such as ear infections, bladder infections, pneumonia, gonorrhea, and E. coli or salmonella infection. Principen is available in generic form.

What Drugs Interact With Unasyn?

Unasyn may interact with allopurinol, probenecid, or other antibiotics.

What Drugs Interact With Principen?

Principen may interact with allopurinol, methotrexate, sulfa drugs, or tetracycline antibiotics. Tell your doctor all medications you are taking. Principen should be used only when prescribed during pregnancy. This medication passes into breast milk. Consult your doctor before breastfeeding.

How Should Unasyn Be Taken?

Unasyn is administered orally in the form of tablets.

How Should Principen Be Taken?

The usual oral dose range of Principen for most infections is 250 to 500 mg 4 times daily for 7-14 days. To treat gonorrhea, a single 3.5 g dose is administered along with probenecid.

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