Drug Groups

approved; investigational

Description

Aripiprazole is an atypical antipsychotic medication used for the treatment of schizophrenia. It has also recently received FDA approval for the treatment of acute manic and mixed episodes associated with bipolar disorder. Aripiprazole appears to mediate its antipsychotic effects primarily by partial agonism at the D2 receptor. In addition to partial agonist activity at the D2 receptor, aripiprazole is also a partial agonist at the 5-HT1A receptor, and like the other atypical antipsychotics, aripiprazole displays an antagonist profile at the 5-HT2A receptor. Aripiprazole has moderate affinity for histamine and alpha adrenergic receptors, and no appreciable affinity for cholinergic muscarinic receptors.

Indication

For the treatment of schizophrenia and related psychotic disorders.

Pharmacology

Aripiprazole is a psychotropic agent belonging to the chemical class of benzisoxazole derivatives and is indicated for the treatment of schizophrenia. Aripiprazole is a selective monoaminergic antagonist with high affinity for the serotonin Type 2 (5HT2), dopamine Type 2 (D2), 1 and 2 adrenergic, and H1 histaminergic receptors. Aripiprazole acts as an antagonist at other receptors, but with lower potency. Antagonism at receptors other than dopamine and 5HT2 with similar receptor affinities may explain some of the other therapeutic and side effects of Aripiprazole. Aripiprazole's antagonism of histamine H1 receptors may explain the somnolence observed with this drug. Aripiprazole's antagonism of adrenergic a1 receptors may explain the orthostatic hypotension observed with this drug.

Affected Organisms

Biotransformation

Hepatic.

Half Life

75-146 hours

Protein Binding

>99%

Elimination

Less than 1% of unchanged aripiprazole was excreted in the urine and approximately 18% of the oral dose was recovered unchanged in the feces.

Distribution

* 4.9 L/kg

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