Chapter 4: Toxicity of Organophosphates and Carbamates

Organophosphate (OP) and carbamate (CM) compounds are commonly used as insecticides around the world. Some of them are extremely toxic to non-target species, including mammals. OP and CM insecticides are acetylcholinesterase (AChE) inhibitors and are commonly referred to as anticholinesterase agents. In addition to their cholinergic mechanisms, these insecticides exert toxicity through non-cholinergic mechanisms, thereby affecting several vital organs and body systems. The brain and skeletal muscles are the major target organs. Cardiovascular, respiratory and immune systems are also affected. There are similarities and differences between and among the toxicity profiles of OPs and CMs. This is due in part to variability in the interaction of each OP or CM with target and non-target receptors, enzymes and proteins. Treatment of CM poisoning rests with atropine, while the treatment of OP poisoning includes atropine in combination with an oxime.