Antagonist effect on dopamine, serotonin, histamine, α₁ and α₂ adrenergic, and muscarinic receptors

Extrapyramidal effects

Neuroleptic malignant syndrome

Pigmentation changes (of eye)

Psychiatric: schizophrenia (alleviate positive symptoms), bipolar disorder (manic phase)

Nonpyschiatric: antemesis, pruritus

central adrenergic-blocking, dopamine-blocking, and minor anticholinergic activity

QT prolongation

Cardiac toxicity

Extrapyramidal effects

Neuroleptic malignant syndrome

Psychiatric: schizophrenia (alleviate positive symptoms), bipolar disorder (manic phase)

Nonpyschiatric: antemesis, pruritus

antiadrenergic, antidopaminergic, and minimal anticholinergic effects; blockades dopamine D1 and D2 receptors (wiki)

Extrapyramidal effects

Neuroleptic malignant syndrome

Anticholinergic side effects such as blurred vision and xerostomia

relieving or minimizing such symptoms of schizophrenia as hallucinations, delusions, and disorganized thought and speech

Blockade of D2 receptors >> 5HT_2A receptors

Some α blockade, but minimal M receptor blockade and much less sedation than the phenothiazines

Extrapyramidal effects

Neuroleptic malignant syndrome

Schizophrenia (positive); bipolar disorder (manic phase)

Huntington’s chorea

Tourette’s syndrome

Blockade of 5HT_2A receptors > blockade of D₂ receptors

Some α and M receptor blockade

Variable H₁ receptor block (all)

diabetes, hypercholesterolemia, hyperprolactinemia, QT prolongation, weight gain

Schizophrenia (improve + and – )
Bipolar (adjunctive with lithium)
 

Agitation in Alzheimer’s and Parkinson’s (low doses)

Major depression

Bipolar

Blockade of 5HT_2A receptors > blockade of D₂ receptors

Some α and M receptor blockade

Variable H₁ receptor block

diabetes, hypercholesterolemia, hyperprolactinemia, QT prolongation, weight gain

Schizophrenia (improve + and – )
Bipolar (adjunctive with lithium)
 

Agitation in Alzheimer’s and Parkinson’s (low doses)

Major depression

Bipolar

Blockade of 5HT_2A receptors > blockade of D₂ receptors

Some α and M receptor blockade

Variable H₁ receptor block

diabetes, hypercholesterolemia, hyperprolactinemia, QT prolongation, weight gain

Schizophrenia (improve + and – )
Bipolar (adjunctive with lithium)
 
Agitation in Alzheimer’s and Parkinson’s (low doses)

Major depression

Bipolar

Blockade of 5HT_2A receptors > blockade of D₂ receptors

Some α and M receptor blockade

Variable H₁ receptor block

diabetes, hypercholesterolemia, hyperprolactinemia, QT prolongation, weight gain

Schizophrenia (improve + and – )
Bipolar (adjunctive with lithium)
 
Agitation in Alzheimer’s and Parkinson’s (low doses)

Major depression

Bipolar

Mechanism uncertain; suppresses inositol signaling and inhibits glycogen synthase kinase-3 (GSK-3), a multifunctional protein kinase

Blocks recycling of membrane

phospholipids, thus depleting PIP2, the membrane precursor to IP3 and DAG

No significant antagonistic actions on autonomic nervous system receptors or specific CNS receptors; no sedative

Tremor, edema, hypothyroidism, renal dysfunction, dysrhythmias, pregnancy category D

Diplopia, nystagmus

Tremor

Weight gain

Bipolar affective disorder – prophylactic use can prevent mood swings between mania and depression