Zosyn vs. Augmentin

Are Zosyn and Augmentin the Same Thing?

Zosyn (piperacillin and tazobactam for injection) and Augmentin (amoxicillin/clavulanate) are combinations of a penicillin antibiotic and a beta-lactamase inhibitor used to treat many different infections caused by bacteria, such as urinary tract infections (UTIs), skin infections, and respiratory tract infections.

Side effects of Zosyn and Augmentin that are similar include nausea, vomiting, stomach pain or upset, diarrhea, headache, skin rash or itching, and vaginal discharge or itching.

Side effects of Zosyn that are different from Augmentin include injection site reactions (swelling, redness, pain, soreness, and irritation), dizziness, agitation, trouble sleeping (insomnia), constipation, runny nose, anxiety,

Side effects of Augmentin that are different from Zosyn include gas and white patches in your mouth or throat.

Both Zosyn and Augmentin may interact with probenecid and blood thinners.

Zosyn may also interact with antibiotics or any other medication used to prevent blood clots.

Augmentin may also interact with allopurinol.

What Are Possible Side Effects of Zosyn?

Common side effects of Zosyn include:

  • swelling,
  • redness,
  • pain,
  • soreness or
  • irritation;
  • dizziness,
  • agitation,
  • trouble sleeping (insomnia),
  • nausea,
  • vomiting,
  • stomach pain or upset,
  • diarrhea,
  • constipation,
  • headache,
  • runny nose,
  • anxiety,
  • skin rash or
  • itching, or
  • vaginal discharge or itching.

Tell your doctor if you have serious side effects of Zosyn including muscle cramps or spasms, swelling of the arms/legs/hands/feet, easy bruising or bleeding, chest pain, confusion, new signs of infection (such as fever, persistent sore throat), severe abdominal or stomach pain, slow/fast/irregular heartbeat, persistent nausea or vomiting, seizures, extreme tiredness, dark or cloudy urine, change in the amount of urine, yellowing eyes or skin, or serious skin reactions (rash, peeling, sores, or blisters).

What Are Possible Side Effects of Augmentin?

Augmentin may cause serious side effects, including:

  • Nausea
  • Vomiting
  • Headache
  • Diarrhea
  • Gas
  • Stomach pain
  • Skin rash or itching
  • White patches in your mouth or throat
  • Vaginal yeast infection (itching or discharge)

Rare and severe side effects of Augmentin can include:

  • watery or bloody diarrhea;
  • pale or yellowed skin, dark colored urine, fever, confusion or weakness;
  • easy bruising or bleeding;
  • skin rash, bruising, severe tingling, numbness, pain, muscle weakness;
  • agitation, confusion, unusual thoughts or behavior, seizures (convulsions);
  • nausea, upper stomach pain, itching, loss of appetite, clay-colored stools, jaundice (yellowing of the skin or eyes); or
  • severe skin reaction -- fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling.

What Is Zosyn?

Zosyn (piperacillin and tazobactam for injection) is a combination of two antibiotics used to treat many different infections caused by bacteria, such as urinary tract infections, bone and joint infections, severe vaginal infections, stomach infections, skin infections, and pneumonia. Zosyn is available in generic form.

What Is Augmentin?

Augmentin (amoxicillin/clavulanate) is a combination antibiotic used to treat bacterial infections including sinusitis, pneumonia, ear infections, bronchitis, urinary tract infections, and infections of the skin.

It is not known if Augmentin is safe and effective in children.


Bowel regularity means a bowel movement every day. See Answer

What Drugs Interact With Zosyn?

Zosyn may interact with probenecid, antibiotics, blood thinners, or any other medication used to prevent blood clots. Tell your doctor all medications you use.

What Drugs Interact With Augmentin?

Augmentin may interact with probenecid.

Augmentin may also interact with allopurinol, blood thinners, or other antibiotics.

How Should Zosyn Be Taken?

The usual total daily dose of Zosyn for adults is 3.375 g every six hours totaling 13.5 g (12.0 g piperacillin/1.5 g tazobactam).

How Should Augmentin Be Taken?

For Adults:

  • The usual adult dose is one 500-mg tablet of Augmentin every 12 hours or one 250-mg tablet of Augmentin every 8 hours. For more severe infections and infections of the respiratory tract, the dose should be one 875-mg tablet of Augmentin every 12 hours or one 500-mg tablet of Augmentin every 8 hours. Adults who have difficulty swallowing may be given the 125 mg/5 mL or 250 mg/5 mL suspension in place of the 500-mg tablet. The 200 mg/5 mL suspension or the 400 mg/5 mL suspension may be used in place of the 875-mg tablet.
  • Two 250-mg tablets of Augmentin should not be substituted for one 500-mg tablet of Augmentin. Since both the 250-mg and 500-mg tablets of Augmentin contain the same amount of clavulanic acid (125 mg, as the potassium salt), two 250-mg tablets are not equivalent to one 500-mg tablet of Augmentin.
  • The 250-mg tablet of Augmentin and the 250-mg chewable tablet should not be substituted for each other, as they are not interchangeable. The 250-mg tablet of Augmentin and the 250-mg chewable tablet do not contain the same amount of clavulanic acid (as the potassium salt). The 250-mg tablet of Augmentin contains 125 mg of clavulanic acid, whereas the 250-mg chewable tablet contains 62.5 mg of clavulanic acid.

For Pediatric Patients

Based on the amoxicillin component, Augmentin should be dosed as follows:

Neonates And Infants Aged under 12 Weeks (under 3 Months)

  • The recommended dose of Augmentin is 30 mg/kg/day divided every 12 hours, based on the amoxicillin component. Experience with the 200 mg/5 mL formulation in this age group is limited, and thus, use of the 125 mg/5 mL oral suspension is recommended.

Patients Aged 12 Weeks (3 Months) And Older

  • The every 12 hour regimen is recommended as it is associated with significantly less diarrhea. However, the every 12 hour suspension (200 mg/5 mL and 400 mg/5 mL) and chewable tablets (200 mg and 400 mg) contain aspartame and should not be used by phenylketonurics.


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Pfizer. Zosyn Product Information.


DailyMed. Augmentin Product Information.


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