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CroFab Side Effects

Generic Name: antivenin (crotalidae) polyvalent

Note: This page contains information about the side effects of antivenin (crotalidae) polyvalent. Some of the dosage forms included on this document may not apply to the brand name CroFab.

Not all side effects for CroFab may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to antivenin (crotalidae) polyvalent: intravenous powder for solution

In addition to its needed effects, some unwanted effects may be caused by antivenin (crotalidae) polyvalent (the active ingredient contained in CroFab). In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking antivenin (crotalidae) polyvalent:

More common
  • Unexplained bleeding or bruising
Less common
  • Cough
  • difficulty in breathing
  • difficulty in swallowing
  • dizziness or lightheadedness
  • fast heartbeat
  • fever
  • hives or welts
  • itching of skin
  • joint pain
  • large, hive-like swellings on the eyelids, face, lips, mouth, and/or tongue
  • muscle pain
  • noisy breathing
  • redness of skin
  • shortness of breath
  • skin rash
  • wheezing

If any of the following side effects occur while taking antivenin (crotalidae) polyvalent, check with your doctor or nurse as soon as possible:

Less common
  • Areas of pain, redness, and swelling
  • chest pain
  • chills
  • discharge from wound
  • pain, tenderness, and warmth at wound site
  • unusual tiredness or weakness

Some of the side effects that can occur with antivenin (crotalidae) polyvalent may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Nausea
Less common

For Healthcare Professionals

Applies to antivenin (crotalidae) polyvalent: injectable solution


The most common adverse events were urticaria and rash.


Very common (10% or more): Urticaria (16%), rash (11%)
Common (1% to 10%): Pruritus, cellulitis, subcutaneous nodule, ecchymosis
Postmarketing reports: Erythema, hyperhidrosis, angioedema


Allergic reaction consisted of urticaria, dyspnea, and wheezing. Serum sickness included urticaria, cough, rash, pruritus, and urticaria. Acute allergic reactions manifested as anxiety, bronchospasm, chills, edema, fever, hypotension, pruritus, rash, urticaria, voice alteration, and/or wheezing.[Ref]

Common (1% to 10%): Allergic reaction, serum sickness
Postmarketing reports: Acute allergic reactions including anaphylaxis or anaphylactoid reactions, delayed allergic reaction.[Ref]


Common (1% to 10%): Coagulation disorder
Postmarketing reports: Delayed or recurrent coagulopathy or thrombocytopenia, thrombocytopenia refractory to treatment, bleeding


Common (1% to 10%): Hypotension
Postmarketing reports: Tachycardia

Nervous system

Common (1% to 10%): General paresthesia, nervousness
Postmarketing reports: Tremor, dizziness, headache[Ref]


Common (1% to 10%): Asthma, cough, increased sputum
Postmarketing reports: Tachypnea, bronchospasm, wheezing, tracheal edema, dyspnea


Common (1% to 10%): Back pain, myalgia
Postmarketing reports: Musculoskeletal chest pain, chills


Common (1% to 10%): Nausea, anorexia, circumoral paresthesia
Postmarketing reports: Tongue swelling, lip swelling


Common (1% to 10%): Chest pain, wound infection, chills
Postmarketing reports: Failure to achieve initial control, recurrent swelling refractory to treatment, prolonged hospitalization, treatment failure resulting in death, chest discomfort, swelling


Common (1% to 10%): Nervousness


Postmarketing reports: Worsening eye sight


1. "Product Information. Crofab (antivenin (crotalidae) polyvalent)" Savage Laboratories, Melville, NY.

More about CroFab (antivenin (crotalidae) polyvalent)

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