From the Guidelines
Quetiapine should be used at a suggested starting dose of 25 mg (immediate release) p.o. stat, with a dose reduction in older patients and patients with hepatic impairment, due to its sedating effects and potential for orthostatic hypotension and dizziness 1.
Key Points
- Quetiapine is an atypical antipsychotic medication used to treat various conditions, including schizophrenia, bipolar disorder, and major depressive disorder.
- The typical dosage ranges from 25-800mg daily, with lower doses often used for sleep or anxiety and higher doses for psychotic disorders.
- Treatment usually begins with a low dose that is gradually increased to minimize side effects, such as sedation, dizziness, dry mouth, weight gain, and increased blood sugar levels.
- Quetiapine works by blocking multiple neurotransmitter receptors in the brain, particularly dopamine and serotonin receptors, which helps regulate mood, thinking, and behavior.
- Regular monitoring of metabolic parameters (weight, blood glucose, lipids) is necessary during treatment, and patients should not stop taking quetiapine abruptly as this can cause withdrawal symptoms.
- Quetiapine may interact with other medications, so patients should inform their healthcare provider about all medications they are taking.
Considerations
- The use of quetiapine in children and adolescents is not well-studied, and its efficacy and safety in this population are not established 1.
- Quetiapine is not approved by the FDA for bipolar disorder in youths, although it is commonly used in clinical settings.
- Other medications, such as lithium, valproate, and olanzapine, may be more effective and safer for use in children and adolescents with bipolar disorder.
Recommendations
- Quetiapine should be used with caution in older patients and patients with hepatic impairment, and the dose should be reduced to minimize the risk of side effects 1.
- Patients should be regularly monitored for metabolic changes, and quetiapine should be tapered off under medical supervision to avoid withdrawal symptoms.
- Quetiapine may be used as an adjunct therapy for major depressive disorder, but its use should be carefully considered and monitored due to the potential for increased risk of suicidality in youths 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Overview of Quetiapine
- Quetiapine is an atypical antipsychotic used in the treatment of schizophrenia, bipolar disorder, and major depressive disorder 2, 3, 4, 5.
- It is available in both immediate-release and extended-release formulations 2.
Mechanism of Action
- Quetiapine acts as an antagonist at serotonin 5-HT2 and dopamine D2 receptors, which is thought to contribute to its antipsychotic effects 2, 3.
- The antidepressant effects of quetiapine are not fully understood, but may be related to its effects on 5-HT2A receptors, 5-HT1A receptors, and noradrenaline reuptake 2.
Efficacy
- Quetiapine has been shown to be effective in the treatment of schizophrenia, bipolar depression, and major depressive disorder 2, 3, 4, 5.
- It has also been used in the treatment of generalized anxiety disorder, although its efficacy in this condition is less well established 6.
Tolerability and Safety
- Quetiapine is generally well tolerated, with common side effects including somnolence, dry mouth, and dizziness 2, 3, 5.
- It has a lower risk of extrapyramidal symptoms compared to some other antipsychotics, and does not elevate plasma prolactin levels 3, 5.
- Quetiapine may be associated with weight gain and changes in metabolic parameters, although the clinical significance of these effects is uncertain 2, 5.
Comparison to Other Antipsychotics
- Quetiapine has been compared to other atypical antipsychotics, including risperidone and olanzapine, and has been found to have a similar efficacy profile 5.
- It may have a more favorable tolerability profile compared to some other antipsychotics, particularly with respect to extrapyramidal symptoms and plasma prolactin levels 5.