Drug Name: Bezlotoxumab

Brand Name: ZINPLAVA

FDA Approval: 2016

Manufacturer: Merck & Co

Primary Indication: Preventing Clostridium Difficile recurrence

ZINPLAVA (Bezlotoxumab) Indications:

Bezlotoxumab is a medication used to lower the chances of recurrence of Clostridium difficile infection (CDI) in high-risk patients who are being treated for CDI with appropriate antibiotics.

It is important to note that Zinplava is to be prescribed only when the patient is already on antibiotics targeted against CDI infection. Patients should not use this drug on their own without a prescription and as monotherapy.

What is CDI?

CDI is a bacterial infection that can cause severe gastrointestinal symptoms, including diarrhea. It is seen commonly in patients who are receiving high-potency antibiotics for a prolonged period of time. Antibiotics are often used to treat CDI but may disrupt the balance of bacteria in the gut, which can increase the risk of recurrence.

How does ZINPLAVA work?

ZINPLAVA works by binding to and neutralizing the toxins produced by C. difficile, thereby reducing the risk of CDI recurrence.

ZINPLAVA (Bezlotoxumab) Dosage and Administration Guidelines

• The recommended dose: A single infusion of 10 mg/kg, given intravenously over a 60-minute period.
• Repeating the dose has not been studied.

Preparation of Diluted Solution

• Inspect the contents of the vial.
• Dilute the drug before infusing it IV. 
• Take the required volume of the drug based on the patient's weight and mix it with 09% saline or 5% Dextrose by gently inverting it.
• Discard the remaining vial.

Storage of Diluted Solution

• Store the diluted solution at room temperature or refrigerate it but avoid freezing it.
• Before giving the infusion, allow the IV bag to come to room temperature.

Administration

• Administer the drug over a minimum of one hour using a sterile, non-pyrogenic, low-protein binding 0.2 micron to 5 micron in-line or add-on filter
• The drug can be infused using a central or peripheral line but IV push or bolus should be avoided. In addition, co-administration using the same line with other drugs should be avoided too

Contraindication to Zinplava:

No contraindications are given in the FDA prescribing information.

Warning & Precautions:

• Heart Failure:

Patients with a history of CHF may develop a worsening of other symptoms when treated with Bezlotoxumab. The risk of heart failure with Zinplava was 12.7% vs 4.8% in the placebo-treated patients in studies. There were deaths reported too.

The manufacturer, therefore, recommends using it only if the benefits outweigh the risks.

ZINPLAVA (Bezlotoxumab) Side Effects:

ZINPLAVA (Bezlotoxumab Drug Interactions

ZINPLAVA is eliminated by catabolism, which means it's unlikely to interact with other drugs metabolized differently in the body. Therefore, no drug-drug interactions are expected.

Use Of Zinplava In Specific Populations

Pregnancy

• Not studied in pregnant women.

Lactation

• Not studied.
• The benefits of treating the mother and the risks of drug exposure in the feeding infant should be calculated when deciding to give it to lactating women.

Pediatric Use

• Not studied/ recommended in children under 18 years of age.

Geriatric Use

• It has the same safety and efficacy profile in older people as younger people.

ZINPLAVA (Bezlotoxumab Mechanism of action (MOA):

ZINPLAVA (Bezlotoxumab) is a human monoclonal antibody that specifically targets and binds to C. difficile toxin B, which results in neutralizing its effects on mammalian cells.

Table summarizing the pharmacokinetics of ZINPLAVA (Bezlotoxumab:

ZINPLAVA Injection Packaging and Description

• It is clear to moderately opalescent, colorless to a pale yellow solution supplied in a single-dose vial of 1,000 mg/40 mL (25 mg/mL)
• The product is preservative-free and sterile

Storage and Handling Instructions for ZINPLAVA Injection

• The Injection should be kept refrigerated at temperatures between 2ºC to 8ºC (36ºF to 46ºF) in its original carton.
• Freezing, shaking the vials, and exposure to sunlight should be avoided.

Patient Counseling Information for ZINPLAVA

• Patients should read the FDA-approved patient labeling or Patient Information.
• It should be informed that the drug is not a substitute for antibiotics and that antibiotics should be continued.
• There is a risk of worsening heart failure in patients with preexisting heart disease.