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AntiPsychotics (also called major tranquilizers or neuropleptics) may be given to calm or sedate a highly aggitated individual whatever the cause. Some antipsychotics have a powerful action against nausea and vomitting. "Psychosis" is a term used to describe mental disorders that prevent the suffer from thinking clearly, recogizing reality, and acting rationally. These disorders include schizophrenia, Bipolar and Paranoia. The precise causes of these illnesses are not known, although a number of factors such as stress, heredity and brain injures may be invovled. Drugs differ in the amount of sedation and are given to calm a highly agtitated or aggressive person, whatever the cause. Act on the brain reducing the transmission of dopamine, causing it to be effective in suppressing abnormal behaviour, reducing aggression, and inducing a generally tranquilizing effect. Depressing the action of dopamine can disturb its balance with another chemical in the brain, acetylcholine, causing signs of expressionless face and shaky hands (parkinsonism). Cogentin is used to counteract this. Antipsychotics also block norepinephrine which lowers the blood pressure. Risks include permanent side effects as well as temporary side effects. The most serious long-term risk is tardive dyskinesisa which may develope after one to five years. This consists of repeated jerking movements of the mouth tongue and face and sometimes hands and feet. Typical antipsychotics are also sometimes referred to as major tranquilizers, because some of them can tranquilize and sedate. This term is increasingly disused as the terminology implies a connection with benzodiazepines ("minor" tranquilizers) when none exists. Antipsychotics are broadly divided into two groups, the typical or first generation antipsychotics and the atypical or second generation antipsychotics. There are also dopamine partial agonists, which are often categorized as atypicals. All antipsychotic drugs tend to block D2 receptors in the dopamine pathways of the brain. This means that dopamine released in these pathways has less effect. Excess release of dopamine in the mesolimbic pathway has been linked to psychotic experiences. It is the blockade of dopamine receptors in this pathway which is thought to control psychotic experiences. Typical antipsychotics are not particularly selective and also block Dopamine receptors in the mesocortical pathway, tuberoinfundibular pathway and the nigrostriatal pathway. Blocking D2 receptors in these other pathways is thought to produce some of the unwanted side effects that the typical antipsychotics can produce (see below). They were commonly classified on a spectrum of low potency to high potency, where potency referred to the ability of the drug to bind to dopamine receptors, and not to the effectiveness of the drug. High potency antipsychotics such as haloperidol typically have doses of a few milligrams and cause less sleepiness and calming effects than low potency antipsychotics such as chlorpromazine and thioridazine, which have dosages of several hundred milligrams. The latter have a greater degree of anticholinergic and antihistaminergic activity which cam counteract dopamine-related side effects. Atypical antipsychotic drugs have a similar blocking effect on D2 receptors. Some also block or partially block serotonin receptors (particularly 5HT2A, C and 5HT1A receptors):ranging from risperidone which acts overwhelmingly on serotonin receptors, to amisulpride which has no serotonergic activity. The additional effects on serotonin receptors may be why some of them can benefit the 'negative symptoms' of schizophrenia. [citation needed] Side Effects:: Antipsychotics are associated with a range of side-effects. It is well recognized that many people (around two thirds in controlled drug trials) discontinue antipsychotics, partly due to adverse effects. Extrapyramidal reactions include acute dystonias, akathisia, parkinsonism (rigidity and tremor), tardive dyskinesia, tachycardia, hypotension, impotence, lethargy, seizures, and hyperprolactinaemia. The atypical antipsychotics (especially olanzapine) seem to cause weight gain more commonly than the typical antipsychotics. The well documented metabolic side effects associated with weight gain include diabetes that, frequently, can be life threatening. Clozapine also has a risk of inducing agranulocytosis, a potentially dangerous reduction in the number of white blood cells in the body. Because of this risk, patients prescribed clozapine may need to have regular blood checks to catch the condition early if it does occur, so the patient is in no danger. One of the more serious of these side effects is tardive dyskinesia,[1] in which the sufferer may show repetitive, involuntary, purposeless movements often of the lips, face, legs or torso. It is believed that there is a greater risk of developing tardive dyskinesia with the older, typical antipsychotic drugs, although the newer antipsychotics are now also known to cause this disorder. It is believed by some that the risk of tardive dyskinesia can be reduced by combining the anti-psychotics with diphenhydramine or benztropine, though this has not been established. Central nervous system damage is also associated with irreversible tardive akathisia and/or tardive dysphrenia. Another antipsychotic side-effect is deterioration of teeth due to a lack of saliva. A potentially serious side effect of many antipsychotics is that they tend to lower an individuals seizure threshold. Chlorpromazine and clozapine particularly, have a relatively high seizurogenic potential. Fluphenazine, haloperidol, pimozide and risperidone exhibit a relatively low risk. Caution should be exercised in individuals that have a history of seizurogenic conditions (such as epilepsy, or brain damage). Another serious side effect is neuroleptic malignant syndrome, in which the drugs appear to cause the temperature regulation centers to fail, resulting in a medical emergency as the patient's temperature suddenly increases to dangerous levels. Another problematic side effect of antipsychotics is dysphoria. Some people suffer few of the obvious side effects from taking antipsychotic medication, while others may have serious adverse effects. Some side effects, such as subtle cognitive problems, may go unnoticed. How they work How they affect you It is thought that some forms of mental illness are caused by an increase in communication between brain cells due to an over activity of a chemical called Dopamine. Dopamine helps correct abnormal thought process and behaviour. Antipsychotics reduce the transmission of nerve signals by binding to recptors of certain brain cells making them less senstive to dopamine. Over dose rating - Medium |