Crotalidae Immune Fab (Equine)

Crotalidae Immune FAB (Equine) is an equine-derived antivenin indicated for the management of adult and pediatric patients with North American Pit Viper envenomation.

• Crotalidae Immune FAB (Equine) is available under the following different brand names: Anavip.

Common side effects of Crotalidae Immune FAB (Equine) include:

• itching
• nausea
• rash
• joint pain
• swelling of extremities
• redness
• headache
• muscle pain
• pain in extremities
• vomiting

Serious side effects of Crotalidae Immune FAB (Equine) include:

• hives
• difficulty breathing
• swelling of the face, lips, tongue, or throat
• severe dizziness

Rare side effects of Crotalidae Immune FAB (Equine) include:

• none 

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, coordination loss, unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Lyophilized powder for reconstitution

• Minimum mouse LD-50 neutralizing units per vial.
• Bothrops asper (Terciopelo or fer-de-lance) 780 units.
• Crotalus simus (formerly Crotalus durissus; Central American Rattlesnake) 790 units.
• Crotalus adamanteus (Eastern Diamondback Rattlesnake) 244 units.
• Crotalus atrox (Western Diamondback Rattlesnake) 147 units.
• Crotalus scutulatus (Mohave Rattlesnake) 185 units.
• Agkistrodon contortrix (Copperhead) 28 units.
• Agkistrodon piscivorus (Cottonmouth or Water Moccasin) 61 units.
• North American Pit Viper envenomation

Adult and pediatric dosage

• Administer as soon as possible after biting in patients who develop any signs of envenomation (eg, local injury, coagulation abnormality, systemic signs of envenomation)
• Initial dose: Reconstituted and diluted solution of 10 vials IV over 1 hour
• Additional dose(s) to achieve initial control: Administer additional 10-vial doses if needed to arrest progressive symptoms and repeat hourly; there is no known maximum dose
• Observation and late dosing: Additional 4-vials dose IV as necessary; infusion over 1 hour

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Crotalidae Immune FAB (Equine) has no noted severe interactions with any other drugs.
• Crotalidae Immune FAB (Equine) has no noted serious interactions with any other drugs.
• Crotalidae Immune FAB (Equine) has no noted moderate interactions with any other drugs.
• Crotalidae Immune FAB (Equine) has no noted minor interactions with any other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, health questions, or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Crotalidae Immune FAB (Equine)?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Crotalidae Immune FAB (Equine)?”

Cautions

• Risk of viral transmission; antivenin is made from equine (horse) plasma
• Trace amounts of cresol from the manufacturing process are contained in the antivenin; localized reactions and generalized myalgias were reported with cresol excipients
• Hypersensitivity
  • May cause allergic reactions; patients with known allergies to horse protein are particularly at risk.
  • Monitor for signs and symptoms of anaphylaxis or hypersensitivity (. eg, urticaria, rash, tightness of chest, wheezing, hypotension); discontinue IV if these symptoms emerge and initiate appropriate treatment

Pregnancy and Lactation

• Unknown if antivenin can cause fetal harm when administered to pregnant women or can affect reproduction capacity
• Animal reproduction studies have not been conducted
• Lactation
  • Unknown if distributed in human breast milk; use caution