Medical Editor: John P. Cunha, DO, FACOEP
Rattlesnake Antivenin (antivenin crotalidae polyvalent) is an antivenin product used only to treat envenomation caused by bites of crotalids (pit vipers) including rattlesnakes, copperhead and cottonmouth moccasins, and others. Common side effects of Rattlesnake Antivenin include allergic reactions such as flushing, itching, hives, swelling of the face/tongue/throat, cough, shortness of breath, blue color to the skin, vomiting, and anaphylaxis (severe allergic reaction).
To be most effective, a dose of Rattlesnake Antivenin should be administered within 4 hours of the bite; it is less effective when given after 8 hours and may be of questionable value after 12 hours. However, it is recommended that Antivenin therapy be given in severe poisonings, even if 24 hours have elapsed since the time of the bite. Rattlesnake Antivenin may interact with beta-adrenergic blockers, and adrenergic agents. Tell your doctor all medications and supplements you use. Tell your doctor if you are pregnant before receiving Rattlesnake Antivenin. Consult your doctor before breastfeeding.
Our Rattlesnake Antivenin (antivenin crotalidae polyvalent) 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.
Immediate systemic reactions (allergic reactions or anaphylaxis) can occur whenever a horse-serum-containing product is administered. An immediate reaction (e.g. shock, anaphylaxis) usually occurs within 30 minutes. Symptoms and signs may develop before the needle is withdrawn and may include apprehension, flushing, itching, urticaria; edema of the face, tongue, and throat; cough, dyspnea, cyanosis, vomiting, and collapse. There have been isolated reports of cardiac arrest and death associated with Antivenin (Crotalidae) Polyvalent (equine origin) use. However, serious immediate reactions to Antivenin are rare. In skin-test-negative patients, Antivenin caused a true immediate sensitivity reaction in less than 1 percent of patients.10
Serum sickness usually occurs 5 to 24 days after administration and its frequency may be related to the number of Antivenin vials administered.30 The incubation period may be less than 5 days, especially in those who have received horse-serum-containing preparations in the past. The usual symptoms and signs are malaise, fever, urticaria, lymphadenopathy, edema, arthralgia, nausea, and vomiting. Occasionally, neurological manifestations develop, such as meningismus or peripheral neuritis. Peripheral neuritis usually involves the shoulders and arms. Pain and muscle weakness are frequently present, and permanent atrophy may develop.
Read the entire FDA prescribing information for Rattlesnake Antivenin (Antivenin (Crotalidae) Polyvalent)