Antitoxin is made from horse serum such as some tetanus antitoxins and the antivenoms for snakebite and scorpion sting. With these, there is a risk of causing a dangerous allergic reaction (allergic shock).
Before you inject a horse serum antitoxin, always have epinephrine ready in case of an emergency. In persons who are allergic or who have been given any kind of antitoxin made of horse serum before, it is a good idea to inject an antihistamine like promethazine (Phenergan) or diphenhydramine (Benadry) 15 minutes before giving antitoxin.
SNAKEBITE ANTIVENIN OR ANTITOXIN
This drug often come in bottles or kits for injection. Antivenins or medicines that protect the body against poisons have been developed for the bites of poisonous snake in many parts of the world.
If you live where people are sometimes bitten or killed by poisonous snakes, find out what antivenins that are available, get them ahead of time and keep them on hand. Some antivenins- the dried or lyophilized form- can be kept without refrigeration. Others need to be kept cold.
The following are a few of the products sold in different parts of Africa :
Ethiopia : Polyvalent antivenin. From Behringwerke Laboratories.
Egypt : Polyvalent antivenin. Available only through the government.
West Africa : Polyvalent antivenin against Echis-Bitis-Naja (carpet viper, gaboon viper and cobra) is usually provided by the government. Antivenin against carpet viper (Echis) alone may be advisable in some areas.
Instructions for the use of snakebite antivenin usually come with the kit. Study them before you use them. The bigger the snake, or the smaller the person, the larger the amount of antivenin needed.
Often 2 or more vials are necessary. To be most helpful, antivenin should be injected as soon as possible after the bite. Be sure to take the necessary precautions to avoid allergic shock.
ANTITOXIN FOR TETANUS
Tetanus Immune Globulin (human) often comes in vials of 250 units. Tetanus antitoxin (horse) often comes in vials of 1,500, 20,000, 40,000 and 50,000 units.
In areas where there are people who have not been vaccinated against tetanus, the medical kits should have an antitoxin for tetanus. They are of 2 forms :
- One made from human serum (tetanus immune globulin, Hyper-tet)
- One made from horse serum (tetanus antitoxin)
If available, use tetanus tetanus immune globulin as it is less likely to cause a severe allergic reaction.
But if you use horse serum tetanus antitoxin, take precautions against allergic reaction :
- If the person suffers from asthma or other allergies or has ever received any kind of antitoxin made from horse serum, give an injection of antihistamine such as promethazine 15 minutes before injecting the antitoxin.
- If a person who is not fully vaccinated against tetanus has a severe wound is likely to cause tetanus. Before he or she develops the signs of tetanus, inject 250 units (1 vial) of tetanus immune globulin. If using tetanus antitoxin, inject 1,500 to 3,000 units. Inject babies with 750 units of tetanus antitoxin.
- If a person develops the signs of tetanus, inject 5,000 units of tetanus immune globulin or 50,000 units of tetanus antitoxin. Give it in many intramuscular injections in the large muscles of the body (buttocks and thighs) or half the amount and can be given intravenously if someone knows how.
- The signs of tetanus usually continue to get worse in spite of treatment with antitoxin. Begin treatment at once and get medical help fast.