Norquetiapine

Norquetiapine

Norquetiapine, also known as N-desalkylquetiapine, is a pharmacologically active metabolite of the atypical antipsychotic drug Quetiapine. It plays a significant role in the therapeutic effects and side effect profile of quetiapine. This article provides a comprehensive overview of norquetiapine, including its pharmacology, clinical significance, and related research.

Pharmacology

Norquetiapine is formed through the hepatic metabolism of quetiapine, primarily by the action of the cytochrome P450 enzyme CYP3A4. It is an important active metabolite that contributes to the overall pharmacological effects of quetiapine.

Mechanism of Action

Norquetiapine exhibits a distinct pharmacological profile compared to its parent compound, quetiapine. It acts as a potent norepinephrine reuptake inhibitor (NRI) and has moderate affinity for the serotonin 5-HT2A receptor, as well as the dopamine D2 receptor. This combination of actions is thought to contribute to its antidepressant and antipsychotic effects.

Pharmacokinetics

The pharmacokinetics of norquetiapine are influenced by the metabolism of quetiapine. After oral administration of quetiapine, norquetiapine reaches peak plasma concentrations within a few hours. It has a half-life of approximately 12 hours, which is longer than that of quetiapine itself.

Clinical Significance

Norquetiapine is believed to contribute significantly to the clinical effects of quetiapine, particularly its antidepressant properties. This is due to its action as a norepinephrine reuptake inhibitor, which is a mechanism shared by many antidepressant medications.

Therapeutic Uses

Quetiapine, and by extension norquetiapine, is used in the treatment of several psychiatric disorders, including:

• Schizophrenia
• Bipolar disorder
• Major depressive disorder (as an adjunctive treatment)

Side Effects

The side effect profile of norquetiapine is similar to that of quetiapine, with common side effects including sedation, weight gain, and metabolic changes. The sedative effects are thought to be due to its antihistaminergic activity.

Research and Development

Ongoing research is exploring the distinct contributions of norquetiapine to the therapeutic effects of quetiapine. Studies are investigating its potential as a standalone treatment for depression and other mood disorders.

Also see

• Quetiapine
• Atypical antipsychotics
• Norepinephrine reuptake inhibitor
• Serotonin receptor