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Botulism antitoxin Side Effects

For the Consumer

Applies to botulism antitoxin: intravenous solution

In addition to its needed effects, some unwanted effects may be caused by botulism antitoxin. In the event that any of these side effects do occur, they may require medical attention.

If any of the following side effects occur while taking botulism antitoxin, check with your doctor or nurse immediately:

More common:
  • Headache
  • hives or welts
  • itching skin
  • nausea
  • rash
  • redness of the skin
Less common:
  • Chills
  • fever
  • throat discomfort
  • Chest pain or discomfort
  • cough
  • difficulty with breathing
  • fast, pounding, or irregular heartbeat or pulse
  • feeling of discomfort
  • increased sweating
  • inflammation of the joints
  • lightheadedness, dizziness, or fainting
  • muscle aches
  • no blood pressure or pulse
  • noisy breathing
  • slow or irregular heartbeat
  • stopping of heart
  • swollen lymph glands
  • tightness in the chest
  • unconsciousness
  • unusual tiredness
Incidence not known:
  • Blurred vision
  • confusion
  • difficulty with moving
  • difficulty with swallowing
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • hoarseness
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • muscle cramping
  • muscle pains or stiffness
  • noisy breathing
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • redness of the skin
  • sweating
  • swollen joints
  • swollen, painful, or tender lymph glands in the neck, armpit, or groin

Minor Side Effects

Some of the side effects that can occur with botulism antitoxin 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:

  • Anxiety
  • decrease in the frequency of urination
  • decrease in urine volume
  • difficulty in passing urine (dribbling)
  • dry mouth
  • hyperventilation
  • irritability
  • painful urination
  • restlessness
  • shaking
  • trouble sleeping
Incidence not known:
  • Bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site

For Healthcare Professionals

Applies to botulism antitoxin: injectable solution


During 1967 to 1977, when larger antitoxin doses were given, hypersensitivity reactions were reported in 9% of patients and anaphylaxis occurred in 2% of patients. within 10 minutes of antitoxin administration.

An investigational heptavalent antitoxin (n=50) was associated with serum sickness (2%) and mild allergic reactions (18%).[Ref]

Hypersensitivity reactions have included urticaria, serum sickness and anaphylaxis. A small challenge dose should be administered before the full dose to screen patients for hypersensitivity.[Ref]


1. "Product Information. Botulism Antitoxin Bivalent (Equine) Types A and B (botulism antitoxin bivalent (Equine) A and B)." Aventis Pharmaceuticals, Swiftwater, PA.

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

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