Pronunciation:

an-tee-VEN-in (kroe-TAL-i-dee) pol-ee-VAY-lent

Brand Names:

• Antivenin Polyvalent

Uses of This Medicine:

Pit viper antivenin belongs to a group of medicines known as immunizing agents. It is used to treat the bites of certain poisonous snakes called pit vipers (crotalids), which are native to Central, North, and South America. Pit vipers include rattlesnakes, such as the Eastern and the Western diamond rattlesnakes; copperheads and cottonmouth moccasins, including those of Korea and Japan; the fer-de-lance and similar species; the tropical rattler (Cascabel) and similar species; the Cantil; and the bushmaster of Central and South America.

Pit viper antivenin is to be used only by or under the supervision of a doctor.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Studies show that children tolerate pit viper antivenin better than do adults. However, children usually have more severe reactions to snakebite poisoning because of the greater amount of poison per body weight. Therefore, children may need larger doses of pit viper antivenin than do adults.

Older adults—

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of pit viper antivenin in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Breast-feeding—

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Proper Use of This Medicine:

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Make certain your health care professional knows if you are on any special diet, such as a low-sodium or low-sugar diet.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Difficulty in breathing or swallowing

hives

itching, especially of feet or hands

reddening of skin, especially around ears

swelling of eyes, face, or inside of nose

unusual tiredness or weakness (sudden and severe)

For up to 24 days after you have received pit viper antivenin, you may develop symptoms of a side effect called serum sickness. The severity of the symptoms and the length of the sickness depend on the amount of pit viper antivenin you were given and how long the treatment lasted. During the 24 days after treatment with pit viper antivenin, check with your doctor if you notice any of the following side effects:

Fever

joint pain

rash and itching

swollen lymph glands

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.