Uses of Antivenin:

• It is used to treat black widow spider bites.
• It may be given to you for other reasons. Talk with the doctor.

What do I need to tell my doctor BEFORE I take Antivenin?

• If you have an allergy to antivenin (Lactrodectus mactans) or any other part of antivenin.
• If you have an allergy to horses or horse serum.
• If you are allergic to antivenin; any part of antivenin; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take antivenin with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Antivenin?

• Tell all of your health care providers that you take antivenin. This includes your doctors, nurses, pharmacists, and dentists.
• Allergic reactions have happened with antivenin. Rarely, some reactions can be very bad or life-threatening. Talk with the doctor.
• Allergic reactions and sometimes death have happened with antivenin in people who have had asthma. Talk with the doctor.
• Sometimes, delayed reactions may happen 8 to 12 days after getting antivenin. Talk with the doctor.
• Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using antivenin while you are pregnant.
• Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

How is this medicine (Antivenin) best taken?

Use antivenin as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• It is given as a shot into a muscle or as an infusion into a vein over a period of time.

What do I do if I miss a dose?

• Call your doctor to find out what to do.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

What are some other side effects of Antivenin?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Muscle cramps.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Antivenin?

• If you need to store antivenin at home, talk with your doctor, nurse, or pharmacist about how to store it.

Consumer Information Use and Disclaimer

• If your symptoms or health problems do not get better or if they become worse, call your doctor.
• Do not share your drugs with others and do not take anyone else's drugs.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
• Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about antivenin, please talk with your doctor, nurse, pharmacist, or other health care provider.
• If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.