Cholinesterase reactants are antidotes that help relieve organophosphate poisoning (FOS). Toxic compounds containing phosphorus include chemical warfare agents such as sarin and herd. However, it is possible to get intoxication with such chemical compounds in peacetime. On the basis of FOS, many drugs have been created to combat harmful insects (Dichlorvos, Thiophos, Chlorophos), as well as some eye drops (Armin, Fosfakol). Similar compounds are used in industry in the production of plastics and varnishes. In case of accidental ingestion of such substances into the body, severe poisoning occurs. And then cholinesterase reactivators come to the rescue.
How do FOS affect the body?
In the human body, a group of enzymes is formed - cholinesterase. They play an important role in the processes of metabolism and the functioning of the nervous system. Organophosphorus compounds, entering the body, inhibit the activity of these enzymes. Acetylcholine begins to accumulate in the tissues. Excess of this substance and leads to the appearance of the following symptoms of intoxication:
- enhanced saliva;
- noisy breathing with wheezing due to sputum in the bronchi;
- narrowed pupils;
- cramps
- cyanosis of the skin;
- muscle paralysis;
- high blood pressure;
- "chemical" bad breath;
- increased sweating.
FOS act on the body as a nerve poison. Intoxication with such substances is extremely dangerous. Lethal outcome due to paralysis of the respiratory muscles. In the photo below you can see a sharp narrowing of the pupils during poisoning of FOS.
How do cholinesterase reactivators work?
In poisoning with FOS, drugs that reactivate cholinesterase act as an antidote. This means that they are antidotes for toxic phosphorus compounds. They can be used in the treatment of poisoning. They are able to quickly neutralize the poison and remove signs of intoxication.
The mechanism of action of cholinesterase reactivators is their ability to restore enzyme activity. The composition of such preparations contains a group of molecules -NOH, which interacts with blocked acetylcholinesterase. As a result, bonds between the FOS molecules and the enzyme are broken. Thus, the activity of cholinesterase is completely restored under the action of an antidote. This leads to the gradual disappearance of symptoms of intoxication.
Types of drugs
The following medications belong to the drugs from the group of cholinesterase reactivators:
- Dipiroxim.
- "Dieticsim."
- Alloxim
- Carboxyme
- "Isonitrosine".
An indication for their use is poisoning with organophosphorus substances. However, cholinesterase blocking also occurs during intoxication with drugs from the cholinomimetic group. The above drugs for poisoning by other means are ineffective. They act only against FOS.
There are no contraindications to the use of cholinesterase reactants.
Description of drugs
FOS antidotes are available as injectable solutions. These are high-speed drugs. Cholinesterase reactants begin to unlock enzymes 15-30 minutes after administration. "Isonitrosine" is a more effective drug. He is able to stop the damage to the central nervous system caused by FOS. Dipiroxim does not penetrate the brain. For this reason, the drug is only able to neutralize the poison, but to a lesser extent affects the symptoms of intoxication.
Recommended dosage
Drugs for poisoning should be administered as soon as possible, with the onset of early symptoms. They are effective only in the first hours after the poison enters the body. Their dosage depends on the severity of intoxication:
- At the initial signs of poisoning, 2-3 ml of atropine solution (0.1%) and FOS antidotes are administered under the skin, their dosage is determined by the instructions for use of each drug. If the manifestations of intoxication do not go away, then the introduction of cholinesterase and atropine reactants is repeated.
- In severe poisoning, 3 ml of atropine and FOS antidotes are injected into a vein. Atropine is administered every 5 minutes, until the rales disappear and the amount of mucus in the respiratory organs decreases. Injections are stopped when dry mouth and dilated pupils appear. These are signs of the effects of atropine on the body. If necessary, enzyme reactivators are introduced again.
On the second day after poisoning, drugs are not administered. This can lead to the development of side effects and a repeated exacerbation of symptoms of intoxication. During antidote therapy, it is necessary to control the level of cholinesterase activity. Usually, 2-3 days after the start of therapy, enzymatic function begins to recover. And after a week, cholinesterase activity doubles.
Side effects
FOS antidotes are strictly prescription drugs. They not only can not be taken without the appointment of a specialist, but should not be used at home. These drugs can only be used in a hospital under the supervision of a doctor. They are intended solely for the hospital treatment of organophosphate poisoning.
Both drugs have pronounced side effects. They can cause a drop in blood pressure, tachycardia, impaired liver function. A serious condition called “cholinergic agitation” may develop with anxiety, delirium, and hallucinations.
If a person accidentally swallows an organophosphorus substance, it is necessary to call a doctor as soon as possible and provide first aid to the victim. The patient is washed with a solution of potassium permanganate and give activated charcoal. If the substance entered the body through the respiratory system, you need to take the person out to fresh air and flush the nasal passages. If the poison is on the skin, then it must be washed off with soap and water.
Further assistance will be provided to the patient in the hospital, only under the supervision of a doctor, it is possible to conduct therapy using antidotes. This means that it is impossible to completely remove the signs of poisoning of FOS at home. It must be remembered that antidotes are effective only in the first hours after intoxication. The faster the ambulance is called, the greater the chances of successful treatment and recovery.