Unasyn vs. Ancef (Cefazolin)

Are Unasyn and Ancef the Same Thing?

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

Unasyn and Ancef are different types of antibiotics. Unasyn is a combination of a penicillin-type antibiotic and a beta-lactamase inhibitor and Ancef is a cephalosporin antibiotic.

Side effects of Unasyn and Ancef that are similar include headache, skin rash, diarrhea, nausea, vomiting, stomach pain, gas, vaginal itching or discharge, itching, thrush (white patches inside your mouth or throat), and injection site reactions (pain, swelling, skin rash, irritation, or a hard lump).

Side effects of Unasyn that are different from Ancef include fever, sore throat, body aches, bloating, and swollen/black/"hairy" tongue.

Side effects of Ancef that are different from Unasyn include stomach cramps, loss of appetite, hives, heartburn, rectal itching, fainting, lightheadedness, confusion, weakness, tiredness, low blood pressure (hypotension), drowsiness, and allergic reactions.

Both Unasyn and Ancef may interact with probenecid.

Unasyn may also interact with allopurinol.

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 Ancef?

Common side effects of Ancef include:

  • injection site reactions (pain, swelling, skin rash, or a hard lump),
  • diarrhea,
  • stomach pain,
  • stomach cramps,
  • nausea,
  • vomiting,
  • loss of appetite,
  • skin rash or itching,
  • hives,
  • white patches or sores inside the mouth or on the lips,
  • vaginal itching or discharge,
  • heartburn,
  • gas,
  • rectal itching,
  • fainting,
  • lightheadedness,
  • confusion,
  • weakness,
  • tiredness,
  • hypotension,
  • drowsiness,
  • headache, and
  • allergic reactions.

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 Ancef?

Cefazolin and dextrose for injection is an antibiotic used to treat many different kinds of bacterial infections.


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What Drugs Interact With Unasyn?

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

What Drugs Interact With Ancef?

Ancef (cefazolin) may interact with probenecid.

How Should Unasyn Be Taken?

Unasyn is administered orally in the form of tablets.

How Should Ancef Be Taken?

The dose of Ancef (cefazolin) varies depending on the condition being treated and its severity. For mild infections, the recommended adult dose is 250 mg to 500 mg every 8 hours. For more severe infections the dose is 500 mg to 1 g every 6 to 8 hours.


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Pfizer. Unasyn Product Information.


Medscape. Rocephin Product Information.


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