Conventional and atypic antipsychotic medications
 There
are a number of different antipsychotic drugs available. They may
be roughly categorized into two groups: conventional and atypical.
Conventional antipsychotics
Conventional (also called traditional) antipsychotic medications
have been used for about fifty years. After using and refined development
of conventional antipsychotics, the psychiatrist have gained large
experience of this type of medication.
The conventional antipsychotic medications
are effective primarily against positive symptoms of schizophrenia
such as hallucinations and delusions (
read more about
positive and negative symptoms).
The effect on positive symptoms may probably
be explained by the way this type of medication affect a chemical
substance of the brain called dopamine. Conventional antipsychotics
seem to block receptors in the brain from taking up information
carried by dopamine.
Dopamine are involved in regulation of many
body functions, e.g. movement, emotions and behavior. An hypothesis
among the researchers is that the positive symptoms of schizophrenia
may be caused by too much dopamine in the brain or very sensitive
dopamine receptors.
Even though conventional antipsychotics are
effective in treating the positive symptoms of schizophrenia, they
do not improve the negative symptoms (
read more about
positive and negative symptoms). Example on negative symptoms
are blunted effect and impaired attention. The reason for the lack
of effect on negative symptoms is probably that these symptoms are
regulated by other brain substances that dopamine.
Examples of conventional antipsychotics are
haloperidole (Haldol), zuclopenthioxol (Cisordinol), perphenazin
(Trilafon), alimemazin (Theralen) and chlorpromazine (Hibernal).
Atypic antipsychotics
The atypical antipsychotic medications have been developed during
the last years.
The atypical antipsychotic medications share
the good preventing effect against psychosis with the conventional
drugs. There is also scientific evidence pointing to a profitable
effect of these drugs on negative symptoms and improved cognitive
function.
A characteristic of the newer atypical antipsychotic
medications is that they are selective. This means that they work
only on the part of the brain that causes the psychotic symptoms,
but not on the part that controls normal muscle movement.
One of the newer atypical antipsychotic medications
is called clozapin. It is effective for treating psychotics
symptoms, and is often used for treating patients where other antipsychotic
drugs have failed. Other examples of atypic antipsychotics are risperidone
(Risperdal), olanzapin (Zyprexa), clozapin (Leponex) and Zeldox.
Beside blocking serotonin receptors in the
brain, atypical antipsychotic medications also block another neurochemical
called serotonin. Some of them also block even more receptors.
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