Raxibacumab
Raxibacumab is an intravenous antibody medicine used with antibacterial drugs to treat inhalational anthrax, and to prevent it when other options aren't available or appropriate.
🧬 Where this information comes from
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Raxibacumab is a specialist lab-made antibody for inhalational anthrax, on the market since about 2012, that blocks the anthrax “protective antigen” so toxins cannot enter cells; because it does not kill the bacteria, it is paired with antibacterial drugs, and used for prevention only when other options are unsuitable. The one-time IV infusion is usually well tolerated; rash, itching, headache and sleepiness are what people most notice. Its boxed warning is for serious allergic reactions, including anaphylaxis (a life-threatening allergic reaction), so it is given only in a monitored setting with epinephrine ready. Report hives, chills or throat tightness immediately, since the antihistamine given beforehand can hide early signs.
Clinical pearls
- It does not reach the brain, so it neither prevents nor treats anthrax meningitis, which is one reason the antibacterial drugs matter.
- Keep taking your prescribed antibiotics exactly as directed, because this infusion adds to them and never replaces them.
- In studies it did not change ciprofloxacin levels or blunt the immune response to the anthrax vaccine.
- Its effectiveness comes from animal studies, because deliberately exposing people to anthrax in trials would not be ethical.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Raxibacumab can cause serious allergic reactions, including anaphylaxis, during or after the IV infusion. Because of this, it must be given in a monitored setting with epinephrine, other emergency equipment and trained staff available.
Warning signs include hives, rash, itching, chills, chest or throat tightness, swelling of the lips or throat, and low blood pressure. Tell your care team right away if you notice any of these.
Patient Information Guide A plain-language walkthrough of Raxibacumab, written from its FDA label.
What Raxibacumab Is Used For
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Raxibacumab is used for inhalational anthrax in these ways:
- Treatment of inhalational anthrax in adults and children, together with appropriate antibacterial drugs.
- Prevention of inhalational anthrax when other therapies are not available or are not appropriate.
How Raxibacumab Works
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Raxibacumab is a monoclonal antibody that binds the protective antigen of the anthrax bacterium. This blocks the antigen from attaching to your cells' receptors. As a result, the anthrax toxins (lethal factor and edema factor) cannot get inside cells to cause harm.
It does not kill the bacteria itself, so it is used along with antibacterial drugs.
Raxibacumab Dosage
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Raxibacumab is given once by IV infusion, diluted in saline, over about two hours and fifteen minutes. The dose is based on body weight, with different weight-based doses for children. It is not taken by mouth, so food does not apply, and a missed dose is not a concern because your care team gives it.
- Diphenhydramine is given within 1 hour beforehand to lower reaction risk.
- The infusion may be slowed or interrupted if you have a reaction.
Dosing details from the FDA-approved label
From the Raxibacumab prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Adults
- Single dose of 40 mg/kg intravenously over 2 hours and 15 minutes after dilution in 0.9% Sodium Chloride Injection, USP (normal saline) to a final volume of 250 mL
- Infusion rate 15 mL/hour for the first 20 minutes, then 125 mL/hour for the remaining infusion
- Premedicate with 25 to 50 mg diphenhydramine (oral or intravenous) within 1 hour prior to the infusion
- Pediatric patients greater than 40 kg
- 40 mg/kg infused over 2 hours and 15 minutes
- Total infusion volume 150 mL of 0.9% Sodium Chloride Injection
- 15 mL/hour for the first 20 minutes, then 75 mL/hour for the remaining infusion
- Premedicate with diphenhydramine within 1 hour prior to the infusion
- Pediatric patients greater than 10 kg to 40 kg
- 60 mg/kg infused over 2 hours and 15 minutes
- Greater than 10 kg to less than 15 kg: 50 mL at 6 mL/hour for first 20 minutes then 25 mL/hour
- 15 kg to less than 30 kg: 100 mL at 6 mL/hour then 50 mL/hour
- 30 kg to 40 kg: 125 mL at 15 mL/hour then 62.5 mL/hour (0.9% Sodium Chloride Injection)
- Premedicate with diphenhydramine within 1 hour prior to the infusion
- Pediatric patients 10 kg or less
- 80 mg/kg infused over 2 hours and 15 minutes
- 5 kg to 10 kg: 40 mL at 3 mL/hour for first 20 minutes then 20 mL/hour
- 3 kg to less than 5 kg: 25 mL at 1.5 mL/hour then 12 mL/hour
- 2 kg to less than 3 kg: 20 mL at 1.2 mL/hour then 10 mL/hour
- 1 kg to less than 2 kg: 15 mL at 1 mL/hour then 7 mL/hour
- Less than 1 kg: 7 mL at 0.5 mL/hour then 3.5 mL/hour (0.45%
- Premedicate with diphenhydramine within 1 hour prior to the infusion
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION • Premedicate with diphenhydramine. ( 2.1 , 2.2 , 5.1 ) • Dilute and administer as an intravenous infusion over 2 hours and 15 minutes. ( 2.3 ) • - Adults: 40 mg/kg raxibacumab. ( 2.1 ) • - Pediatrics greater than 40 kg: 40 mg/kg raxibacumab. ( 2.2 ) • - Pediatrics greater than 10 kg to 40 kg: 60 mg/kg raxibacumab. ( 2.2 ) • - Pediatrics 10 kg or less: 80 mg/kg raxibacumab. ( 2.2 ) 2.1 Dose and Schedule for Adults Administer raxibacumab as a single dose of 40 mg/kg intravenously over 2 hours and 15 minutes after dilution in 0.9% Sodium Chloride Injection, USP (normal saline) to a final volume of 250 mL. Administer 25 to 50 mg diphenhydramine within 1 hour prior to the raxibacumab infusion to reduce the risk of occurrence and/or the severity of an infusion reaction. Diphenhydramine route of administration (oral or intravenous) should be based on the temporal proximity to the start of the raxibacumab infusion [see Warnings and Precautions ( 5.1 ) , Adverse Reactions ( 6.1 )] . 2.2 Dose and Schedule for Pediatric Patients The recommended dose for pediatric patients is based on weight as shown in Table 1 . Table 1. Recommended Pediatric Dose Pediatric Body Weight Pediatric Dose Greater than 40 kg 40 mg/kg Greater than 10 kg to 40 kg 60 mg/kg 10 kg or less 80 mg/kg Premedicate with diphenhydramine within 1 hour prior to the raxibacumab infusion to reduce the risk of occurrence and/or the severity of an infusion reaction. Diphenhydramine route of administration (oral or intravenous) should be based on the temporal proximity to the start of the raxibacumab infusion. Infuse raxibacumab over 2 hours and 15 minutes. No pediatric patients were studied during the development of raxibacumab. The dosing recommendations in Table 1 are derived from simulations designed to match the observed adult exposure to raxibacumab at a 40 mg/kg dose [see Use in Specific Populations ( 8.4 )] . 2.3 Preparation and Administration of Raxibacumab The recommended dose of raxibacumab is weight-based, given as an intravenous infusion after dilution in a compatible solution to a final volume of 250 mL in adults or to a volume indicated based on the child’s weight ( Table 2 ).
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Raxibacumab Side Effects
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The most common side effects seen in healthy volunteers were:
Common side effects
- Rash
- Itching
- Pain in an arm or leg
- Sleepiness
- Headache
- Injection site reaction, redness or pain
When to get medical help
- Get help right away for signs of a severe allergic reaction: chest or throat tightness, swelling of the lips or throat, trouble breathing, or feeling faint (low blood pressure).
- Tell your care team at once if you develop hives, widespread rash, itching or chills during or after the infusion.
- Report any new or worrying symptom during the infusion so it can be slowed or stopped.
Serious allergic reactions can happen. Tell your care team right away about chest or throat tightness, swelling, trouble breathing or faintness.
Raxibacumab Warnings and Precautions
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- Serious allergic reactions and anaphylaxis can occur during or after the infusion. It must be given where emergency care is available.
- You will be monitored closely during and after the infusion.
- Diphenhydramine premedication does not prevent anaphylaxis and may mask or delay symptoms.
- Raxibacumab does not treat or prevent meningitis.
- Effectiveness is based on animal studies only.
Raxibacumab Interactions
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Studies found no meaningful interactions with the two products tested.
- Ciprofloxacin: neither drug changed the levels of the other.
- Anthrax Vaccine Adsorbed (AVA): raxibacumab did not affect the immune response to the vaccine.
Interactions listed in the FDA-approved label
From the Raxibacumab prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Ciprofloxacin: Co-administration of 40 mg/kg raxibacumab intravenously with intravenous or oral ciprofloxacin in human subjects did not alter the PK of either ciprofloxacin or raxibacumab.
- Anthrax Vaccine Adsorbed (AVA): Co-administration of 40 mg/kg raxibacumab intravenously (Day 1) with a SC AVA regimen (Days 1, 15, and 29) did not affect the immunogenicity of AVA.
Read the label’s full interactions text
7 DRUG INTERACTIONS 7.1 Ciprofloxacin Co-administration of 40 mg/kg raxibacumab intravenously with intravenous or oral ciprofloxacin in human subjects did not alter the PK of either ciprofloxacin or raxibacumab [see Clinical Pharmacology ( 12.3 )] . 7.2 Anthrax Vaccine Adsorbed (AVA) Co-administration of 40 mg/kg raxibacumab intravenously (Day 1) with a SC AVA regimen (Days 1, 15, and 29) did not affect the immunogenicity of AVA [see Clinical Pharmacology ( 12.3 )] .
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before Taking Raxibacumab
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- There are no contraindications listed.
- Pregnancy: no human data; animal studies in rabbits showed no birth defects. Untreated anthrax is very risky in pregnancy.
- Breastfeeding: no information on milk passage; discuss with your doctor.
- Children: safety and pharmacokinetics have not been studied; doses are weight-based estimates.
- Adults 65 and older: no dose change needed.
Raxibacumab Overdose
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There is no clinical experience with raxibacumab overdose. If one happens, you would be monitored for any signs or symptoms of side effects.
What Raxibacumab Does in the Body
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Raxibacumab binds free protective antigen with high affinity. This stops the antigen from binding to cell receptors and blocks anthrax toxins from entering cells. In rats given lethal toxin, treated animals survived 7 days, while untreated animals died in a median of 16 hours.
How Your Body Processes Raxibacumab
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Raxibacumab is given into a vein, so it reaches your bloodstream directly. It spreads somewhat into tissues. It is cleared by the body with virtually no kidney elimination. Sex, race and age did not meaningfully change how the body handles it. It has not been evaluated in children.
How to Store Raxibacumab
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refrigerated at 2°C to 8°C (36°F to 46°F). DO NOT FREEZE. Store vial in original carton until time of use.
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Raxibacumab: Pharmacist Answers to Common Questions
Quick, plain-English answers to the questions patients ask most about Raxibacumab — the kind of thing our pharmacy team would talk through with you at the counter.
What is raxibacumab for?
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How will I get it?
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What side effects should I expect?
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What reaction should I worry about?
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Does raxibacumab replace my antibiotics?
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Is it safe in pregnancy?
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Is Raxibacumab available over the counter?
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When was Raxibacumab first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More About Raxibacumab on HelloPharmacist
Raxibacumab Forms and Strengths (How It Comes)
Raxibacumab is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Raxibacumab inactive ingredients by manufacturer.
Injection
How this form is used
- Raxibacumab is used with antibacterial drugs to treat inhalational anthrax in adults and children.
- Raxibacumab is used to prevent inhalational anthrax when other therapies are not available or appropriate.
- Raxibacumab is diluted and given as an intravenous infusion over 2 hours and 15 minutes.
- Raxibacumab is given in a monitored setting prepared to manage anaphylaxis.
- Raxibacumab is preceded by diphenhydramine within 1 hour before the infusion.
- Raxibacumab infusion may be slowed or stopped if signs of a reaction appear.
Raxibacumab on the U.S. Market: Products, Makers and Brands
How Raxibacumab appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 1 Raxibacumab product record with the FDA, mostly as injection; the earliest marketing or approval year on record is 2012.
Also listed with the FDA, not a patient dose form: Unfinished liquid (1) — bulk drug substance and unfinished product sold to compounders and other manufacturers to finish, and multi-item kits. These aren’t counted in the dose-form total above.
Compare Raxibacumab Products
A representative set of FDA-listed product records for Raxibacumab — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 50 mg/mL | Intravenous | Emergent BioDefense Operations Lansing | BLA | View NDC → |
Showing 1 of 1 products — FDA National Drug Code Directory. See every product, package size and price: browse all 1 Raxibacumab NDCs →
Raxibacumab Side Effects Reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Raxibacumab — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Raxibacumab in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Raxibacumab FDA Approval History
How Raxibacumab went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Raxibacumab was first approved by the FDA in 2012 (Brand: RAXIBACUMAB · Human Genome Sciences Inc.). It remains available in U.S. pharmacies today.
Source: Drugs@FDA.
Raxibacumab Recall History
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Raxibacumab recalls since July 2021.
✅No Raxibacumab recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Oct 8, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 1366567 1 dose form · 1 strength
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Dose form (SCDF) Injection RxCUI 1724255In current FDA listingsClinical drug / strength (SCD) 34 ML raxibacumab 50 MG/MLRxCUI 1366571
Look up RxCUI 1366567 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Raxibacumab Supply and Shortage Status
Whether Raxibacumab is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Who Makes Raxibacumab: Manufacturers and Labelers
One company lists Raxibacumab products with the FDA. By number of product records, the largest are Emergent Manufacturing Operations Baltimore LLC. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Raxibacumab Drug Class (RxNorm)
Raxibacumab belongs to the Anthrax Protective Antigen-directed Antibody class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for This Raxibacumab Page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Emergent Manufacturing Operations Baltimore LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →