Organophosphorus compounds

Organophosphorus compounds - a substance whose molecules have a phosphorus-carbon bond, i.e., the atom of phosphorus directly related to the carbon atom (unlike other containing phosphorus and carbon substances, such as phosphates, where the bond between C and P is carried out through oxygen). To organophosphorus compounds include derivatives of phosphorous hydrogen (PH3) - phosphines. Primary and secondary phosphines chemically unstable, capable to catch on fire by itself. Phosphines are strong poisons. Strong toxicity and exceptionally high biological activity of organophosphorus compounds formed the basis of their application as toxic substances (see Chemical weapons).
Organophosphorus compounds in small concentrations are able to inhibit cholinesterase activity and other enzyme systems in the body of animals that enables the use of organophosphorus compounds as drugs for the treatment of such serious diseases like glaucoma, cancer and others have also been Found mutagenic action of organophosphorus compounds, which opens great prospects for the study of heredity. Organophosphorus compounds as pesticides - see Dezinficiruyusch tools, agricultural Pesticides.

Organophosphorus compounds - butiphos, karbofos, metaphos, methyl nitrophos, octamethyl, the drug M 81 and M 82, typos, chlorophos, fosfamida is highly toxic to humans. Clinical signs of poisoning different organophosphorus compounds (OPhC) is similar, but the speed of occurrence, severity of pathological manifestations depend on the degree of toxicity of various chemicals in this group, and on the way of exposure.
The main role in the mechanism of action of organophosphorus compounds plays the inhibition of the activity of the enzyme cholinesterase participating in the destruction of chemical mediator (conductor) of nervous excitement acetylcholine. The accumulation of the latter leads to changes in the activity of the nervous system and internal organs.
Acute poisoning. The latent period - from several minutes to several hours. The first signs of poisoning are headache, dizziness, weakness, drowsiness, changing insomnia, nausea, vomiting, abdominal cramps, increase sluno - and sweating, reduced inhibition (cramps), blurred vision, nystagmus, reduced tendon reflexes. Later joined by respiratory disorders (cough, shortness of breath, asthmatic attacks, when listening to a rich dry and moist rales), twitching muscles, unstable gait, may increase pain and liver, leukocytosis, limfopenia, eosinopenia, neutrophilic shift to the left. In severe acute poisoning occurs loss of consciousness, convulsions muscles of the whole body, significantly expressed respiratory distress, reminiscent of pulmonary edema (fiery breath, rich moist rales, zianoz lips), and coma.
Chronic poisoning. Develops toxic neurasthenia (headaches, dizziness, sleep disturbance, fatigue, irritability, memory loss) in combination with vegetative disorders (increased sweating, bright dermographism, arterial hypotension, aetiology), diarrhoea events (nausea, decreased appetite). In the future, can join mental changes, depression, decreased intelligence, microcinema organic lesions of the Central nervous system Early sign of toxic action of organophosphorus compounds is decreasing cholinesterase activity in the serum.
First aid and treatment. In acute poisoning is to remove the victim from the poisoned area to fresh air to stop receiving the poison into the body through the respiratory tract. Remove contaminated clothing. To remove the poison from the skin 10-15% ammonia solution or 2-5% solution of sodium bicarbonate (soda) with subsequent processing of warm water with soap. When hit FOS in the eyes - rinse 2% solution of sodium bicarbonate. At hit in the stomach to produce copious lavage with warm water or 2% solution of sodium bicarbonate, and then to give a saline laxative. When the first signs of intoxication held antidote therapy 0.1% solution of atropine: when mild intoxication - 1 to 2 ml intramuscularly, medium - 2-4 ml intramuscularly or intravenously, severe - 4 - 6 ml intramuscularly or intravenously, repeating every 3-8 minutes until light of atropinizatsii (dilated pupils, dry mucous membranes). In severe acute poisoning introduction atropine can be increased to 30 ml or more. As a means of antidote therapy can be used Pentagon, tropatsin, amizil, reaktivatory (reductants activity) cholinesterase: 2-PAM, TMB-4, dipiroksim.
In addition antidote therapy, is symptomatic treatment: when convulsions, geksenal, barbitala-sodium (Medina), shortness of breath - artificial respiration, oxygen, heart funds (korazol, kordiamin, mezaton), glucose, for the prevention of pneumonia antibiotics, sulfanilamides. In the administration of Avenyn and methylacetophenone, do not inhibit cholinesterase activity, antidote therapy is not carried out, are appointed symptomatic funds.
In chronic intoxication is a tonic and symptomatic treatment.