BeneFIX Side Effects Center

Last updated on RxList: 1/10/2022
BeneFIX Side Effects Center

What Is BeneFIX?

BeneFIX, Coagulation Factor IX (recombinant) is a man-made protein similar to a natural protein in the body that helps the blood to clot used to treat or prevent bleeding in people with hemophilia B. BeneFIX is not for treating people with hemophilia A factor VII deficiency.

What Are Side Effects of BeneFIX?

Common side effects of BeneFIX include:

  • fever,
  • injection site reactions (pain, redness, or swelling),
  • chills,
  • headache,
  • flushing (warmth, redness, or tingly feeling under your skin),
  • weakness,
  • nausea,
  • vomiting, or
  • dizziness

Dosage for BeneFIX

Dosage and duration of treatment for all factor IX products depends on the severity of the factor IX deficiency, the location and extent of bleeding, and the patient's clinical condition, age and recovery of factor IX.

What Drugs, Substances, or Supplements Interact with BeneFIX?

Other drugs may interact with BeneFIX. Tell your doctor all medications and supplements you use.

BeneFIX During Pregnancy or Breastfeeding

During pregnancy, BeneFIX should be used only when prescribed. It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our BeneFIX, Coagulation Factor IX (recombinant) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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BeneFIX Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives, itching; wheezing, tightness in your chest, difficult breathing, fast heartbeats, blue lips, feeling like you might pass out; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • weight gain, swelling in your waist, hands, or lower legs;
  • loss of appetite;
  • fever or chills;
  • continued bleeding after treatment;
  • new or worsened bleeding; or
  • signs of excessive blood clotting--sudden numbness or weakness (especially on one side of the body), slurred speech, problems with vision or balance, chest pain, coughing up blood, or pain, swelling, warmth and redness in one or both legs.

Common side effects may include:

  • nausea;
  • headache;
  • dizziness;
  • altered sense of taste;
  • mild skin rash; or
  • pain, redness, itching, stinging, or other irritation where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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The most serious adverse reactions are systemic hypersensitivity reactions, including bronchospastic reactions and/or hypotension and anaphylaxis and the development of high-titer inhibitors necessitating alternative treatments to factor IX replacement therapy.

The most common adverse reactions observed in clinical trials (frequency > 5% of PTPs or PUPs) were headaches, dizziness, nausea, injections site reaction, injection site pain and skin-related hypersensitivity reactions (e.g., rash, hives).

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

During uncontrolled, open-label clinical studies with BeneFIX conducted in previously treated patients (PTPs), 113 adverse reactions with known or unknown relation to BeneFIX therapy were reported among 38.5% (25 of 65) of subjects (with some subjects reporting more than one event) who received a total of 7,573 infusions. These adverse reactions are summarized in Table 2.

Table 2: Adverse Reactions Reported for PTPs*

Body System Adverse Reaction Number of patients (%)
Blood and lymphatic system disorders Factor IX inhibition† 1 (1.5%)
Eye disorders Blurred vision 1 (1.5%)
Gastrointestinal disorders Nausea 4 (6.2%)
Vomiting 1 (1.5%)
General disorders and administration site conditions Injection site reaction 5 (7.7%)
Injection site pain 4 (6.2%)
Fever 2 (3.1%)
Infections and infestations Cellulitis at IV site 1 (1.5%)
Phlebitis at IV site 1 (1.5%)
Headache 7 (10.8%)
Dizziness 5 (7.7%)
Nervous system disorders Taste perversion (altered taste) 3 (4.6%)
Shaking 1 (1.5%)
Drowsiness 1 (1.5%)
Renal and urinary disorders Renal infarct‡ 1 (1.5%)
Respiratory, thoracic and mediastinal disorders Dry cough 1 (1.5%)
Hypoxia 1 (1.5%)
Chest tightness 1 (1.5%)
Skin and subcutaneous Rash 4 (6.2%)
disorders Hives 2 (3.1%)
Vascular disorders Flushing 2 (3.1%)
*Adverse reactions reported within 72 hours of an infusion of BeneFIX.
†Low-titer transient inhibitor formation.
‡The renal infarct developed in a hepatitis C antibody-positive patient 12 days after a dose of BeneFIX for a bleeding episode. The relationship of the infarct to the prior administration of BeneFIX is uncertain.

In the 63 previously untreated patients (PUPs), who received a total of 5,538 infusions, 10 adverse reactions were reported among 9.5% of the patients (6 out of 63) having known or unknown relationship to BeneFIX. These events are summarized in Table 3.

Table 3: Adverse Reactions Reported for PUPs*

Body System Adverse Reaction Number of Patients (%)
Blood and lymphatic system disorders Factor IX inhibition† 2 (3.2%)
General disorders and Injection site reaction 1 (1.6%)
administration site conditions Chills 1 (1.6%)
Respiratory, thoracic and mediastinal disorders Dyspnea (respiratory distress) 2 (3.2%)
Skin and subcutaneous disorders Hives 3 (4.8%)
Rash 1 (1.6%)
*Adverse reactions reported within 72 hours of an infusion of BeneFIX.
†Two subjects developed high-titer inhibitor formation during treatment with BeneFIX.


In clinical studies with 65 PTPs (defined as having more than 50 exposure days), a low-titer inhibitor was observed in one patient. The inhibitor was transient, the patient continued on study and had normal factor IX recovery pharmacokinetics at study completion (approximately 15 months after inhibitor detection).

In clinical studies with pediatric PUPs, inhibitor development was observed in 2 out of 63 patients (3.2%), both were high-titer (> 5 BU) inhibitors detected after 7 and 15 exposure days, respectively. Both patients were withdrawn from the study.

The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors, including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to BeneFIX with the incidence of antibodies to other products may be misleading.

Thromboembolic Complications

All subjects participating in the PTP, PUP and surgery studies were monitored for clinical evidence of thrombosis. No thrombotic complications were reported in PUPs or surgery subjects. One PTP subject experienced a renal infarct (see Table 2). Laboratory studies of thrombogenecity (fibrinopeptide A and prothrombin fragment 1 + 2) were obtained in 41 PTPs and 7 surgery subjects prior to infusion and up to 24 hours following infusion. The results of these studies were inconclusive. Out of 29 PTP subjects noted to have elevated fibrinopeptide A levels post-infusion of BeneFIX, 22 also had elevated levels at baseline. Surgery subjects showed no evidence of significant increase in coagulation activation.

Postmarketing Experience

The following post-marketing adverse reactions have been reported for BeneFIX: inadequate factor IX recovery, inadequate therapeutic response, inhibitor development [see CLINICAL PHARMACOLOGY], anaphylaxis [see WARNINGS AND PRECAUTIONS], angioedema, dyspnea, hypotension, and thrombosis.

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

There have been post-marketing reports of thrombotic events, including life-threatening SVC syndrome in critically ill neonates, while receiving continuous-infusion BeneFIX through a central venous catheter. Cases of peripheral thrombophlebitis and DVT have also been reported. In some, BeneFIX was administered via continuous infusion, which is not an approved method of administration [see DOSAGE AND ADMINISTRATION]. The safety and efficacy of BeneFIX administration by continuous infusion have not been established [see WARNINGS AND PRECAUTIONS].

Read the entire FDA prescribing information for BeneFIX (Coagulation Factor IX Recombinant for Injection)

© BeneFIX Patient Information is supplied by Cerner Multum, Inc. and BeneFIX Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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