Phenothiazine antipsychotic poisoning
Introduction
Introduction to phenothiazine antipsychotic drug poisoning Excessive phenothiazine antipsychotic drugs cause poisoning. Antipsychotics refers to drugs that can treat various psychiatric disorders and various psychiatric symptoms, also known as strong tranquilizers or nerve blockers. This class of drugs has many clinical uses, and chlorpromazine is the most widely used. The intestinal absorption of this group of drugs is very unstable after oral administration, and it has the effect of inhibiting intestinal peristalsis. The intestines can often stay for a long time, and are distributed in the whole body after absorption. It is most abundant in brain and lung tissues, mainly metabolized by the liver, and most of it is excreted in the form of glucuronide or oxysulfide. The drug excretion time is longer, the half-life is 10 to 20 hours, and the effect lasts for several days. basic knowledge The proportion of illness: 0.05% (this disease is more common in patients taking long-term use of phenothiazine antipsychotic drugs, the incidence rate accounts for 0.05% of the total number of patients taking the drug) Susceptible people: no special people Mode of infection: non-infectious Complications: arrhythmia, hypotension
Cause
The cause of phenothiazine antipsychotic drug poisoning
Excessive phenothiazine antipsychotic drugs cause poisoning.
Phenothiazine drugs mainly act on the network structure to relieve mental symptoms such as anxiety, illusion delusions and pathological thinking. These effects are considered to be drugs that inhibit central nervous system dopamine receptors and reduce the production of catechol ammonia. As a result, this group of drugs can inhibit brain stem vasomotor and vomiting reflex, as well as block alpha adrenergic receptors, antihistamines and anticholinergic effects.
Prevention
Phenothiazine antipsychotic drug poisoning prevention
1. The application of such drugs to patients with mental illness requires monitoring of their family members.
2. Master the indications and dosage, and do not abuse.
3. Long-term application requires close observation of clinical symptoms and adverse reactions, and regular examination of blood, if necessary, check liver function.
4. Pay attention to various adverse reactions when combined with other drugs. This medicine should not be combined with piroxicam, otherwise it may lead to excessive blood lithium concentration and poisoning.
Complication
Phenothiazine antipsychotic drug poisoning complications Complications, arrhythmia, hypotension
Cardiovascular system is mainly characterized by arrhythmia such as tachycardia, hypotension and even shock.
Symptom
Symptoms of phenothiazine antipsychotic drug poisoning Common symptoms Paralysis coma, convulsion, exfoliative dermatitis, swallowing difficulty, intestinal peristalsis, reduction of thermoregulatory disorder
Due to the large safety range of the therapeutic dose of this kind of medicine, the daily amount can be as small as 20-30 mg, which is as much as 1~2g, so the lethal poisoning caused by excess is rare, and the side effects are more in the course of treatment. Common is the extrapyramidal reaction, which can be seen in the following three categories:
1 tremor paralysis syndrome;
2 sitting still can not (akathisia);
3 acute dystonia reaction such as torticollis, difficulty swallowing, closed jaws, etc. In addition, there are still orthostatic hypotension, temperature regulation disorder, etc. during the treatment, allergic to chlorpromazine drugs, even if the therapeutic dose also causes exfoliation Dermatitis, agranulocytosis and cholestasis of hepatitis and death.
It is generally believed that when a dose reaches 2 to 4 g, there may be an acute poisoning reaction. Because of the obvious anticholinergic effect of these drugs, patients often have tachycardia, high temperature and intestinal peristalsis decrease; -adrenergic block The effect leads to vasodilation and blood pressure lowering. Because the drug has quinidine-like membrane stability and myocardial inhibition, the patients with poisoning have arrhythmia, prolonged PR and QT interval, ST and T wave changes, and an acute overdose can also have a vertebra. In vitro symptoms, coma after large doses of poisoning, respiratory depression, but systemic convulsions are rare, vomit, gastric lavage and urine toxicity analysis and blood drug concentration determination, are helpful for diagnosis and prognosis.
Examine
Examination of phenothiazine antipsychotic drug poisoning
(1) Laboratory examination: examination of blood electrolytes, renal function, glucose, blood gas analysis, detection of CPK levels when suspected of NMS, urine analysis of suspected NMS when checking myoglobin, urine sample plus chlorinated high-iron-sulfuric acid test solution, If there is a purple reaction, the chlorpromazine poisoning, qualitative and quantitative analysis.
(2) Electrocardiogram: QT/QRS extension can often be issued, ST-T changes, and conduction is abnormal.
(3) Necessary imaging examinations.
Diagnosis
Diagnosis and identification of phenothiazine antipsychotic drugs
Diagnosis based on medication history and symptoms.
(1) Excessive tricyclic antidepressants.
(2) An excess of antihistamines.
(3) Excessive cocaine.
