Other drug names:	A-Am  An-Az  B  C-Ch  Ci-Cz  D-Dh  Di-Dz  E  F  G  H  I-J  K-L  M-Mh  Mi-Mz  N-Nh  Ni-Nz  O  P-Pl  Pm-Pz  Q-R  S-Sn  So-Sz  T-To  Tp-Tz  U-V  W-Z  0-9

Another commonly used name in the U.S. and Canada is antivenin (Latrodectus mactans).

• Immunizing agent, passive

Black widow spider antivenin belongs to a group of medicines known as immunizing agents. It is used to treat patients with serious symptoms caused by the bites of the black widow spider.

Black widow spider antivenin is to be used only by or under the supervision of a doctor. It is available in the following dosage form:

Parenteral
• Injection (U.S. and Canada)

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 black widow spider antivenin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to black widow spider antivenin, to horses, or to any products of horse origin. Also tell your health care professional if you are allergic to any other substances, such as preservatives. Before giving you this medicine, your doctor will do a skin test or a conjunctival (eye) test to see whether you are at risk of having a serious allergic reaction to black widow spider antivenin or horse serum (contained in this medicine).

Pregnancy—Studies on effects in pregnancy have not been done in either humans or animals. However, poisoning by the black widow spider may result in miscarriages if left untreated.

Breast-feeding—It is not known whether black widow spider antivenin passes into the breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who have received this medicine and who wish to breast-feed should discuss this with their doctor.

Children—Although there is no specific information comparing use of black widow spider antivenin in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in 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 black widow spider 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.

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 health care professional if you are using any other prescription or nonprescription (over-the-counter [OTC]) 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:

• 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) 

Other side effects may occur that usually do not need medical attention. However, check with your doctor if any of the following side effects continue or are bothersome:

• Feeling of discomfort;  fever;  inflammation of joints;  itching;  muscle aches;  rash;  swollen lymph glands 

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

Developed: 06/24/1995