ICD-10 Specific code F20.3: Undifferentiated schizophrenia

Amisulpride is a neuroleptic. Amisulpride binds selectively with a high affinity to human dopaminergic D₂/D₃ receptor subtypes whereas it is devoid of affinity for D₁, D₄ and D₅ receptor subtypes.

It has been proposed that aripiprazole’s efficacy in schizophrenia and Bipolar I Disorder is mediated through a combination of partial agonism at dopamine D₂ and serotonin 5-HT_1A receptors and antagonism of serotonin 5-HT_2A receptors.

Brexpiprazole is an atypical antipsychotic agent. The pharmacology of brexpiprazole is believed to be mediated by a modulatory activity at the serotonin and dopamine systems that combines partial agonist activity at serotonergic 5-HT_1A and at dopaminergic D₂ receptors with antagonist activity at serotonergic 5-HT_2A receptors, with similar high affinities at all of these receptors.

Cariprazine is indicated for the treatment of schizophrenia in adult patients. The mechanism of action of cariprazine is not fully known. However the therapeutic effect of cariprazine may be mediated through a combination of partial agonist activity at dopamine D₃, D₂ (Ki values of 0.085-0.3 nM versus 0.49-0.71 nM respectively) and serotonin 5-HT_1A receptors (Ki values of 1.4-2.6 nM), and antagonist activity at serotonin 5-HT_2B, 5-HT_2A and histamine H₁ receptors (Ki values of 0.58-1.1 nM, 18.8 nM and 23.3 nM, respectively).

Chlorpromazine is a phenothiazine neuroleptic. Chlorpromazine has depressant actions on the Central Nervous System, with alpha-adrenergic blocking and anticholinergic activities. It has anti-emetic, anti-puritic, serotonin-blocking and weak anti-histamine properties and slight ganglion blocking activity.

Haloperidol is an antipsychotic belonging to the butyrophenones group. It is a potent central dopamine type 2 receptor antagonist, and at recommended doses, has low alpha-1 antiadrenergic activity and no antihistaminergic or anticholinergic activity.

Levomepromazine resembles chlorpromazine and promethazine in the pattern of its pharmacology. It possesses anti-emetic, antihistamine and anti-adrenaline activity and exhibits a strong sedative effect.

Lurasidone is a selective blocking agent of dopamine and monoamine effects indicated for the treatment of schizophrenia. Lurasidone binds strongly to dopaminergic D₂- and to serotonergic 5-HT_2A and 5-HT₇ receptors. Lurasidone does not bind to histaminergic or muscarinic receptors.

Olanzapine is an antipsychotic, antimanic and mood stabilising agent that demonstrates a broad pharmacologic profile across a number of receptor systems.

Paliperidone is a selective blocking agent of monoamine effects, whose pharmacological properties are different from that of traditional neuroleptics. Even though paliperidone is a strong D₂-antagonist, which is believed to relieve the positive symptoms of schizophrenia, it causes less catalepsy and decreases motor functions to a lesser extent than traditional neuroleptics.

Perphenazine is a depressant which blocks dopamine receptors in the central nervous system. It binds to dopamine D₁ and D₂ receptors and inhibits their activity. Its antiemetic action is mainly due to the inhibition of D₂ receptors in the center of the vomiting. Perphenazine also binds to alpha adrenergic receptors and in conjunction with G proteins activate the phosphatidylinositol-calcium system.

Pimozide is an orally active neuroleptic drug which blocks central dopaminergic receptors. Pimozide antagonises many of the actions of amphetamine and apomorphine.

Risperidone is a selective monoaminergic antagonist with unique properties. Although risperidone is a potent D₂ antagonist, which is considered to improve the positive symptoms of schizophrenia, it causes less depression of motor activity and induction of catalepsy than classical antipsychotics.

Sulpiride is a member of the group of substituted benzamides, which are structurally distinct from the phenothiazines, butyrophenones and thioxanthenes. One of the characteristics of sulpiride is its bimodal activity, as it has both antidepressant and neuroleptic properties. Schizophrenia characterised by a lack of social contact can benefit strikingly.

Trifluoperazine is one of the phenothiazine class of compounds and as such has many pharmacodynamic effects which relate to its therapeutic actions and side effects. The most notable action of phenothiazines is antagonism at dopamine receptors in the CNS.