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Generic name: bezlotoxumab systemic

Brand names: Zinplava

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, Intravenous [preservative free]:

Zinplava: 1000 mg/40 mL (40 mL) [contains polysorbate 80]


Mechanism of Action

Bezlotoxumab is a human IgG1 monoclonal antibody which binds to C. difficile toxin B and neutralizes it to prevent its toxic effects; bezlotoxumab does not bind to C. difficile toxin A.



7.33 L


Metabolized via catabolism


Eliminated primarily through catabolism

Half-Life Elimination

~19 days

Use: Labeled Indications

Clostridioides (formerly Clostridium) difficile infection, adjunctive therapy: To reduce recurrence of Clostridioides (formerly Clostridium) difficile infection (CDI) in patients ≥18 years of age who are receiving antibacterial drug treatment of CDI and are at a high risk for CDI recurrence

Limitations of use: Bezlotoxumab is not indicated for the treatment of CDI. Bezlotoxumab is not an antibacterial drug and should only be used in conjunction with antibacterial drug treatment of CDI.


There are no contraindications listed in the manufacturer's labeling.

Dosage and Administration

Dosing: Adult

Clostridioides (formerly Clostridium) difficile infection, adjunctive therapy: IV: 10 mg/kg as a single dose during antibacterial treatment for Clostridioides (formerly Clostridium) difficile infection. Repeat doses have not been studied.

Dosing: Geriatric

Refer to adult dosing.


Must be diluted prior to infusion. Immediately after removing vial from refrigerator, withdraw appropriate volume from vial and transfer to infusion bag of either normal saline or D5W to a final concentration between 1 to 10 mg/mL. Do not use vials if solution is discolored or if particulates are visible. Gently invert to mix; do not shake.


IV: Infuse IV over 60 minutes through a sterile, nonpyrogenic, low-protein binding 0.2 to 5 micron in-line or add-on filter. Do not administer as an IV push or bolus. May be infused via a central line or peripheral catheter. Do not coadminister other drugs simultaneously through the same infusion line. If infusion solution was refrigerated, allow to come to room temperature prior to administration. Infusion should be completed within 16 hours of preparation (if stored at room temperature) or within 24 hour (if refrigerated).


Store intact vials at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light. Do not shake vials. Solutions diluted for infusion may be stored either at room temperature for up to 16 hours or refrigerated at 2°C to 8°C (36°F to 46°F) for up to 24 hours. Infusion must be completed within these time frames. If refrigerated, allow the intravenous bag to come to room temperature prior to use. Do not freeze diluted solution.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

>10%: Cardiovascular: Cardiac failure (exacerbation:13%)

1% to 10%:

Cardiovascular: Cardiac failure (2%)

Central nervous system: Headache (4%)

Gastrointestinal: Nausea (7%)

Miscellaneous: Infusion related reaction (10%; including nausea, fatigue, fever, dizziness, headache, dyspnea, and hypertension), fever (5%)

<1%, postmarketing, and/or case reports: Ventricular tachyarrhythmia


Concerns related to adverse effects:

  • Heart failure: Heart failure has been reported at a higher rate in patients treated with bezlotoxumab (compared to placebo), primarily occurring in patients with underlying heart failure. Additionally, a higher mortality rate due to cardiac failure, infection, and respiratory failure was observed in patients with a history of heart failure who received bezlotoxumab (compared to those who received placebo). In patients with a history of heart failure, bezlotoxumab use should be reserved for situations when the benefits outweigh risks.

Concurrent drug therapy issues:

  • Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.


Pregnancy Considerations

Bezlotoxumab is a humanized monoclonal antibody (IgG1). Potential placental transfer of human IgG is dependent upon the IgG subclass and gestational age, generally increasing as pregnancy progresses. The lowest exposure would be expected during the period of organogenesis (Palmeira 2012; Pentsuk 2009).

Patient Education

What is this drug used for?

  • It is used to lower the chance of a type of bacterial infection called C. diff from coming back.

Frequently reported side effects of this drug

  • Nausea
  • Loss of strength and energy

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

  • Severe headache
  • Dizziness
  • Passing out
  • Vision changes
  • Heart problems like cough or shortness of breath that is new or worse, swelling of the ankles or legs, abnormal heartbeat, weight gain of more than five pounds in 24 hours, dizziness, or passing out
  • Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. 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 the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Source: Wolters Kluwer Health. Last updated February 4, 2020.