SCHIZOPHRENIA-TREATMENTS-INTRODUCTION
Psychoses are the obsessively positive or negative states of mental condition which comprise of schizophrenia, delusions, and hallucinations.
There are drugs known as neuroleptics are primarily used to treat psychoses.
Dopamine the central excitatory neurotransmitter is having several pathways in the system. If it gets overactive especially at receptors in its mesocortical pathway leads to the negative and cognitive symptoms of schizophrenia and in its mesolimbic pathways which leads to the positive and obsessive symptoms of schizophrenia.
Mechanisms of Actions:-
The main target of antipsychotics to correct psychoses is acting on the two dopaminergic pathways of the mesocortical and the mesolimbic regions, particularly upon the D-2 receptors. The overactivity of dopamine in these receptors is blocked by these drugs to correct the psychoses.
Potency Differences:-
The antipsychotic drugs differing in potencies depending upon their affinity to the D-2 receptors.
Haloperidol and thiothixene have higher potency because of their higher affinity to the D-2 receptors. In contrast, chlorpromazine and thioridazine have lower potency as their affinity for D-2 receptors is lower. But all of them are equally efficacious as they produce the same effects at their dosage calculated according to their potency. A high potent drug brings the effect at a low dosage and vice versa
Administration:-
By orally or intramuscularly.
Kinetics:-
They are absorbed in different degrees by oral routes and readily enters into the blood-brain barrier and distributed in large in various tissue compartments. This volume is further enlarged by the intramuscular route.
All drugs are metabolized in the liver by the induction of Cytochrome P-450 enzyme and hence any drug which is competitively metabolized by this enzyme may affect the effectiveness of the drug if given concomitantly.
All neuroleptic drugs may not become apparently active therapeutically immediately after administration until several weeks, but their sedative effect may onset rapidly.
Schizophrenia by nature cannot be cured but can be controlled by antipsychotic drugs.
