Antipsychotics (also known as neuroleptics) belong among the most commonly used drugs in psychiatry. Their development has come a long way in order to increase their efficiency, while reducing their side effects.
Generally, the antipsychotics are compounds capable of blocking certain receptors on neurons (nerve cells) in the brain. These receptors are important for function of the so-called neurotransmitters, which are substances transmitting impulses between the nerve cells. Imbalance of certain neurotransmitter systems is considered to be essential for development of a number of psychiatric illnesses. By blocking the receptors, the efficiency of certain neurotransmitters is decreased, resulting in return of the equilibrium with disappearance of clinical symptoms.
There are many psychiatric diseases, when the antipsychotics are effective. Perhaps the most common are schizophrenia, certain forms of bipolar disorder, psychotic behavioral disorders and Tourette syndrome. In addition, some antipsychotics have great effect in acute confusion and delirant conditions, including delirium tremens. Some neuroleptics relieve pain and may be used in certain cases in pain therapy.
Types of antipsychotics
There are two basic groups of antipsychotic agents - typical and atypical. Typical antipsychotics are developmentally more original and tend to have stronger side effects.
Today, only few active substances are used. They have stronger both therapeutic effects and side-effects. The used substances include chlorpromazine, levomepromazine and haloperidol.
The majority of antipsychotics belong into this group. They have less frequent side-effects. Most commonly used substances are amisulpride, sulpiride, tiaprid, melperon, risperidone, ziprasidone, clozapine, olanzapine and quetiapine.
Because of direct effect on the central nervous system, antipsychotics have many side-effects. Typical antipsychotics can cause serious movement disorders similar to Parkinson's disease (this is due to strong inhibition of dopamine receptors). Chronic usage of antipsychotics may cause somnolence, fatigue and depression. The users also commonly complain about dry mouth, headache, digestive disorders (vomiting, constipation) and fainting. Treated patients have frequently elevated cholesterol level. Very unpleasant are sexual disorders such as male impotence and loss of libido. Very rare and dangerous complications include severe rhythm disorders and neuroleptic malignant syndrome.