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QUEtiapine (Monograph)

Drug class: Atypical Antipsychotics

Medically reviewed by Drugs.com on Jul 10, 2025. Written by ASHP.

Warning

    Increased Mortality in Geriatric Patients with Dementia-related Psychosis
  • Substantially higher mortality rate (4.5%) in geriatric patients with dementia-related psychosis [off-label] receiving atypical antipsychotic agents (e.g., quetiapine, aripiprazole, olanzapine, risperidone) compared with those receiving placebo (2.6%).

  • Most fatalities resulted from cardiac-related events (e.g., heart failure, sudden death) or infections (e.g., pneumonia).

  • Atypical antipsychotics are not approved for the treatment of patients with dementia-related psychosis.

    Suicidal Thoughts and Behaviors
  • Antidepressants increased risk of suicidal thinking and behavior (suicidality) compared with placebo in children, adolescents, and young adults (18–24 years of age) with major depressive disorder and other psychiatric disorders.

  • In pooled data analyses, risk of suicidality was not increased in adults >24 years of age and apparently was reduced in adults ≥65 years of age with antidepressant therapy compared with placebo.

  • Closely monitor all patients who are started on quetiapine therapy for clinical worsening and emergence of suicidal thoughts behaviors; advise family members and/or caregivers of the need for close observation and communication with the prescribing clinician.

  • Quetiapine is not approved for use in pediatric patients less than 10 years of age.

Introduction

Atypical antipsychotic agent.

Uses for QUEtiapine

Schizophrenia

Used orally (as quetiapine fumarate conventional tablets [Seroquel] or extended-release tablets [Seroquel XR]) for the treatment of schizophrenia in adults and pediatric patients 13–17 years of age.

For pediatric patients with schizophrenia, symptom profiles can be variable. Medication therapy for pediatric patients should only be initiated after a thorough diagnostic evaluation and careful consideration of risks associated with medication treatment. Medication treatment for pediatric patients is indicated as part of a total treatment program that often includes psychological, educational, and social interventions.

American Psychiatric Association (APA) and Department of Veterans Affairs/Department of Defense recommend antipsychotic medications for acute and long-term maintenance treatment of schizophrenia. Choice of antipsychotic should be based on patient preference, past response to therapy, concurrent medical conditions, and medication-specific factors (e.g., adverse effect profile, available formulations, potential drug interactions, receptor binding profiles, pharmacokinetic considerations).

An American Academy of Child and Adolescent Psychiatry (AACAP) practice parameter recommends antipsychotic medication as a primary treatment for schizophrenia spectrum disorders in children and adolescents. Choice of antipsychotic medication in pediatric patients should be individualized based on FDA labeling, adverse effect profiles, patient and family preferences, cost, and clinician familiarity.

Bipolar Disorder

Used orally (as quetiapine fumarate conventional tablets [Seroquel] or extended-release tablets [Seroquel XR]) for the acute treatment of manic episodes (conventional tablets) and manic or mixed episodes (extended-release tablets) associated with bipolar I disorder as monotherapy and in conjunction with lithium or divalproex in adults and pediatric patients 10–17 years of age, for the acute treatment of depressive episodes associated with bipolar disorder in adults, and as an adjunct to lithium or divalproex for the maintenance treatment of bipolar I disorder in adults.

Pediatric patients with bipolar I disorder may have variable patterns of periodicity of manic or mixed symptoms. Medication therapy for pediatric patients should only be initiated after a thorough diagnostic evaluation and careful consideration of risks associated with medication treatment. Medication treatment for pediatric patients is indicated as part of a total treatment program that often includes psychological, educational, and social interventions.

APA recommends lithium or valproate plus an antipsychotic agent for first-line treatment of severe manic or mixed episodes; for patients with less severe symptoms, monotherapy with lithium, valproate, or an antipsychotic agent may be appropriate. Selection of a specific treatment is based on clinical factors (e.g., illness severity, associated features, patient preference, adverse effect profile of the medication). Recommended agents for maintenance treatment include lithium and valproate. Role of quetiapine not addressed.

Department of Veterans Affairs/Department of Defense recommends lithium or quetiapine monotherapy for first-line treatment of acute mania associated with bipolar disorder; recommended alternative agents include olanzapine, paliperidone, and risperidone. If none of these agents are suitable based on patient preference or characteristics, other alternatives include aripiprazole, asenapine, carbamazepine, cariprazine, haloperidol, valproate, or ziprasidone. In patients with breakthrough episodes or unsatisfactory response to initial treatment, lithium or valproate in combination with an antipsychotic (haloperidol, asenapine, quetiapine, olanzapine, or risperidone) recommended. Recommended agents for maintenance therapy include lithium and quetiapine; alternatives include olanzapine, paliperidone, or risperidone. May also use aripiprazole, olanzapine, quetiapine, or ziprasidone in combination with lithium or valproate for prevention of mania recurrence.

AACAP recommends pharmacotherapy as primary treatment for mania in bipolar I disorder in children and adolescents. Standard therapies include lithium, valproate, and/or atypical antipsychotic agents. Choice of therapy in pediatric patients should be based on evidence of efficacy, phase of illness, presence of confounding symptoms, adverse effect profiles, history of response to medication, and patient and family preferences.

Major Depressive Disorder

Used orally (as quetiapine extended-release tablets (Seroquel XR) as an adjunct to antidepressants for the treatment of major depressive disorder in adults.

Guidelines from APA and the Department of Veterans Affairs/Department of Defense state that there is no evidence to suggest superiority of one first-line antidepressant over another. Recommended first-line agents for initial treatment of major depressive disorder include bupropion, mirtazapine, a selective serotonin-reuptake inhibitor (SSRI), a serotonin-norepinephrine reuptake inhibitor (SNRI), trazodone, vilazodone, or vortioxetine. For patients with no response or inadequate response to initial treatment with an antidepressant, options include changing to a different antidepressant or psychotherapy, or augmentation with psychotherapy or another pharmacological agent.

Generalized Anxiety Disorder

Used for the management of refractory generalized anxiety disorder in adults [off-label]. International experts state quetiapine has been found to be effective as monotherapy for generalized anxiety disorder; however, given concerns about its adverse effect profile (e.g., metabolic changes, arrhythmias), it is not recommended as first-line therapy.

Obsessive-Compulsive Disorder

Used as adjunctive treatment in the management of obsessive-compulsive disorder (OCD) in adults [off-label] .

Legacy guideline from APA list SSRIs (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline) as first-line pharmacotherapy for OCD. If a patient does not respond to one SSRI, they may switch to a different SSRI, clomipramine, venlafaxine, or mirtazapine, or augment their current SSRI with an atypical antipsychotic agent.

Posttraumatic Stress Disorder

Used for the management of refractory posttraumatic stress disorder (PTSD) in adults [off-label].

International experts state quetiapine has been found to be effective in PTSD, but should only be used when standard treatments have failed or have not been tolerated due to a higher rate of adverse effects. Department of Veterans Affairs and Department of Defense guidelines state there is insufficient evidence to recommend for or against use of quetiapine for the treatment of PTSD.

QUEtiapine Dosage and Administration

General

Patient Monitoring

Dispensing and Administration Precautions

Administration

Oral Administration

Administer conventional (immediate release) tablets orally, generally 2–3 times daily without regard to meals.

Administer extended-release tablets orally once daily, preferably in the evening, without food or with a light meal (<300 calories).

Swallow the extended-release tablets whole and do not split, chew, or crush.

When switching from other antipsychotic agents to quetiapine, abrupt discontinuance of previous agent may be acceptable for some patients with schizophrenia, but gradual discontinuance may be appropriate for others. In all cases, minimize period of overlapping antipsychotic administration.

In patients being switched from long-acting (depot) parenteral antipsychotic therapy to oral quetiapine therapy, administer first oral dose in place of next scheduled depot injection of the long-acting preparation.

Periodically reevaluate need for continuing any existing drug therapy for symptomatic relief of adverse extrapyramidal effects.

Dosage

Available as quetiapine fumarate; dosage is expressed in terms of quetiapine.

Patients receiving conventional tablets (immediate-release) can be switched to the extended-release formulation at the equivalent daily dosage given once daily. Individual dosage adjustments may be necessary.

Reinitiating therapy: In patients previously treated with quetiapine, dosage titration is not necessary if reinitiated after a drug-free period <1 week; if reinitiated after a drug-free period >1 week, generally titrate dosage as with initial therapy.

Pediatric Patients

Schizophrenia
Oral

Conventional tablets (adolescents 13–17 years of age): Initially, 25 mg twice daily.

Increase dosage to 50 mg twice daily on the second day, then 100 mg twice daily on the third day, 150 mg twice daily on the fourth day, and then 200 mg twice daily on the fifth day of therapy. Dosage thereafter may be adjusted in increments no greater than 100 mg daily within the recommended dosage range of 400–800 mg daily. Based on response and tolerability, may be administered in 2 or 3 divided doses.

Extended-release tablets (adolescents 13–17 years of age): Initially, 50 mg once daily.

Increase dosage to 100 mg daily on the second day, then 200 mg on the third day, 300 mg on the fourth day, then 400 mg once daily on fifth day of therapy. Dosage thereafter may be adjusted to a target dosage of 400–800 mg once daily.

Manufacturer states efficacy of continued therapy >6 weeks has not been systematically evaluated. Continue therapy in responsive patients as long as clinically necessary and reassess need for continued therapy periodically.

Bipolar Disorder
Oral

Conventional tablets (pediatric patients 10–17 years of age): Initially, 25 mg twice daily.

Increase dosage to 50 mg twice daily on the second day, then 100 mg twice daily on the third day, 150 mg twice daily on the fourth day, and then 200 mg twice daily on the fifth day of therapy. Dosage thereafter may be adjusted in 100-mg daily increments to a target dosage of 400–600 mg daily in 2 or 3 divided doses.

Extended-release tablets (pediatric patients 10–17 years of age): Initially, 50 mg once daily.

Increase dosage to 100 mg once daily on the second day, then 200 mg once daily on the third day, 300 mg once daily on the fourth day, then 400 mg once daily on fifth day of therapy. Dosage thereafter may be adjusted to a target dosage of 400–600 mg once daily.

Manufacturer states efficacy of continued therapy >3 weeks has not been systematically evaluated. Continue therapy in responsive patients as long as clinically necessary and reassess need for continued therapy periodically.

Adults

Schizophrenia
Oral

Conventional tablets: Initially, 25 mg twice daily.

Increase dosage in increments of 25–50 mg 2 or 3 times daily on the second and third days, as tolerated, to a target dosage range of 300–400 mg daily in 2 or 3 divided doses by the fourth day.

Make subsequent dosage adjustments at intervals of not less than 2 days, usually in increments or decrements of 25–50 mg twice daily.

Dosages ranging from 150–750 mg daily were effective in acute treatment in clinical trials. Maximum recommended dosage is 750 mg daily. For maintenance treatment, recommended target dosage is 400–800 mg daily in 2 or 3 divided doses; maximum recommended dosage is 800 mg daily.

Extended-release tablets: Initially, 300 mg once daily.

Dosage thereafter may be adjusted by up to 300 mg daily at intervals as short as 1 day to a target dosage range of 400–800 mg once daily. Maximum recommended dosage is 800 mg daily.

Manufacturer states efficacy of continued therapy for >6 weeks with the conventional tablets has not been systematically evaluated. Continue therapy in responsive patients as long as clinically necessary and reassess need for maintenance therapy and appropriate dosage for such treatment periodically.

Bipolar Disorder
Acute Mania
Oral

Conventional tablets: Initially, 100 mg daily in 2 divided doses. Increase dosage (in increments of 100 mg daily in 2 divided doses) to 400 mg daily on the fourth day of therapy. Make subsequent adjustments in increments of ≤200 mg daily up to a maximum dosage of 800 mg daily by the sixth day of therapy.

Recommended target dosage range is 400–800 mg daily.

Extended-release tablets: Initially, 300 mg once daily.

Dosage thereafter may be adjusted to 600 mg once daily on the second day, then further adjusted, to a target dosage of 400–800 mg once daily on the third day.

Manufacturer states efficacy of continued therapy for >12 weeks as monotherapy or for >3 weeks in conjunction with divalproex or lithium has not been systematically evaluated. Continue therapy in responsive patients as long as clinically necessary and reassess need for continued therapy periodically.

Maintenance Therapy
Oral

Recommended maintenance dosage of 400–800 mg daily (in conjunction with divalproex or lithium). Continue therapy in responsive patients as long as clinically necessary and reassess need for continued therapy periodically.

Bipolar Depression
Oral

Conventional or extended-release tablets: Initially, 50 mg once daily at bedtime.

Dosage thereafter increased to 100 mg once daily on the second day, 200 mg on the third day, then 300 mg on the fourth day.

Manufacturer states efficacy of continued therapy for >8 weeks has not been systematically evaluated.

Major Depressive Disorder
Oral

Extended-release tablets: Initially, 50 mg once daily at bedtime.

Dosage thereafter maintained at 50 mg once daily on the second day, then increased to 150 mg once daily on the third day. Target dosage generally ranges from 150–300 mg once daily.

Continue therapy in responsive patients as long as clinically necessary and reassess need for continued therapy periodically.

Generalized Anxiety Disorder† [off-label]
Oral

50–300 mg daily.

Obsessive Compulsive Disorder†
Oral

25–400 mg daily.

Posttraumatic Stress Disorder†
Oral

50–300 mg daily.

Dosage Modifications for Concomitant Use of Drugs Affecting Hepatic Microsomal Enzymes

In patients receiving concomitant therapy with potent cytochrome P-450 (CYP) isoenzyme 3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone), reduce dosage of quetiapine conventional or extended-release tablets to one-sixth of original dosage. Increase quetiapine dosage by 6-fold when potent CYP3A4 inhibitor is discontinued.

In patients receiving chronic (e.g., longer than 7–14 days) therapy with potent CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, St. John’s wort [Hypericum perforatum]), increase dosage of quetiapine conventional or extended-release tablets by up to 5-fold of original dosage. Make dosage adjustments based on clinical response and tolerability. Return quetiapine dosage to original dosage within 7–14 days when potent CYP3A4 inducer is discontinued.

Switching to or Concomitant Use with Other Antipsychotic Agents

Manufacturer states that there are no systematically collected data that specifically address switching from other antipsychotic agents to quetiapine or concerning concomitant use of quetiapine with other antipsychotic agents. Although abrupt discontinuance of the previous antipsychotic agent may be acceptable for some patients with schizophrenia, gradual discontinuance may be most appropriate for others. In all cases, minimize the period of overlapping antipsychotic administration. In patients being switched from long-acting (depot) parenteral antipsychotic therapy to oral quetiapine therapy, administer first oral dose of quetiapine (conventional or extended-release tablets) in place of the next scheduled dose of long-acting preparation. Periodically reevaluate need for continuing existing drugs used for the symptomatic relief of extrapyramidal manifestations.

Special Populations

Hepatic Impairment

Conventional tablets: Initially, 25 mg daily; increase dosage by 25–50 mg daily according to clinical response and tolerability until an effective dosage is reached.

Extended-release tablets: Initially, 50 mg once daily; increase dosage by 50 mg daily according to clinical response and tolerability until an effective dosage is reached.

Renal Impairment

No dosage adjustment necessary.

Geriatric Patients

Consider a slower rate of dosage titration and a lower target dosage in geriatric patients and in patients who are debilitated or have a predisposition to hypotensive reactions. Adjust dosage with caution.

Conventional tablets: Initially, 25 mg twice daily to minimize risk of orthostatic hypotension and associated syncope. May increase dosage in increments of 50 mg daily according to clinical response and tolerability. If hypotension occurs during dosage titration, return to previous dosage in titration schedule.

Extended-release tablets: Initially, 50 mg once daily; increase dosage by 50 mg daily according to clinical response and tolerability until an effective dosage is reached. If hypotension occurs during dosage titration, return to previous dosage in titration schedule.

Cautions for QUEtiapine

Contraindications

Warnings/Precautions

Warnings

Increased Mortality in Geriatric Patients with Dementia-related Psychosis

Possible increased risk of death with use of atypical antipsychotics in geriatric patients with dementia-related psychosis. (See Boxed Warning.)

Atypical antipsychotics are not approved for the treatment of dementia-related psychosis.

Suicidal Thoughts and Behaviors

Possible worsening of depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior in both adult and pediatric patients with major depressive disorder; may persist until clinically important remission occurs. (See Boxed Warning.) However, suicide is a known risk of depression and certain other psychiatric disorders, and these disorders themselves are the strongest predictors of suicide.

Appropriately monitor and closely observe patients receiving quetiapine for any reason, particularly during initiation of therapy (i.e., the first few months) and during periods of dosage adjustments.

Anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia, hypomania, and/or mania may be precursors to emerging suicidality. Consider changing or discontinuing therapy in patients whose depression is persistently worse or in those with emerging suicidality or symptoms that might be precursors to worsening depression or suicidality, particularly if severe, abrupt in onset, or were not part of the patient’s presenting symptoms.

Prescribe in smallest quantity consistent with good patient management to reduce risk of overdosage.

Other Warnings/Precautions

Cerebrovascular Events in Geriatric Patients with Dementia-related Psychosis

An increased incidence of adverse cerebrovascular events (cerebrovascular accidents and transient ischemic attacks), including fatalities, has been observed in geriatric patients with dementia-related psychosis treated with certain atypical antipsychotic agents (aripiprazole, olanzapine, risperidone) in placebo-controlled studies.

Atypical antipsychotics are not approved for the treatment of dementia-related psychosis.

Neuroleptic Malignant Syndrome

Neuroleptic malignant syndrome (NMS), a potentially fatal syndrome requiring immediate discontinuance of the drug and intensive symptomatic treatment and monitoring, reported rarely. Clinical signs and symptoms include hyperpyrexia, muscle rigidity, altered mental status, and autonomic instability, in addition to possible elevations in creatinine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure.

Metabolic Changes

Metabolic changes such as hyperglycemia/diabetes mellitus, dyslipidemia, and weight gain reported with atypical antipsychotic agents. Changes in these metabolic profiles should be managed as clinically appropriate.

Periodically monitor blood glucose in patients with preexisting diabetes mellitus for worsening of glucose control and perform fasting blood glucose tests at baseline and periodically for patients with risk factors for diabetes mellitus (e.g., obesity, family history of diabetes). All patients receiving atypical antipsychotic agents should be monitored for symptoms of hyperglycemia, including polydipsia, polyuria, polyphagia, and weakness. If manifestations of hyperglycemia occur in any patient, fasting blood glucose testing is recommended.

Undesirable changes in lipid parameters observed in patients treated with some atypical antipsychotic agents. Appropriate clinical monitoring is recommended during quetiapine therapy, including fasting blood lipid testing at the beginning of therapy and periodically during treatment.

Increases in weight observed in clinical trials. Monitor weight regularly in patients receiving quetiapine therapy. When treating pediatric patients with quetiapine for any indication, assess weight gain against that expected with normal growth.

Tardive Dyskinesia

Tardive dyskinesia, a syndrome of potentially irreversible, involuntary dyskinetic movements, reported infrequently. Consider discontinuance of quetiapine.

Hypotension

Orthostatic hypotension reported. Use with caution in patients with known cardiovascular or cerebrovascular disease and/or conditions that would predispose patients to hypotension (e.g., dehydration, hypovolemia, concomitant antihypertensive therapy).

Falls

Somnolence, postural hypotension, and motor and sensory instability reported, which may lead to falls; as a consequence, fractures or other injuries may occur.

For patients with diseases or conditions or receiving other drugs that could exacerbate these effects, complete a fall risk assessment when initiating antipsychotic treatment and periodically during long-term therapy.

Hypertension (Children and Adolescents)

Systolic and diastolic blood pressure increases reported in children and adolescents receiving quetiapine.

Check blood pressure during quetiapine initiation and periodically during therapy in children and adolescents.

Leukopenia, Neutropenia, and Agranulocytosis

Leukopenia, neutropenia, and agranulocytosis possible.

Check CBC frequently during first few months of therapy in patients with a preexisting low WBC or a history of drug-induced leukopenia or neutropenia. Discontinue quetiapine at the first sign of a decline in leukocyte count in the absence of other causative factors.

Monitor patients with clinically significant neutropenia for fever or other signs or symptoms of infection and promptly treated if such signs and symptoms occur. In patients with severe neutropenia (absolute neutrophil count [ANC] <1000/mm3), discontinue quetiapine and monitor the leukocyte count until recovery occurs.

Cataracts

Possible lenticular changes during long-term use; ophthalmologic examination of the lens by methods adequate to detect cataract formation (e.g., slit lamp exam) recommended upon initiation of quetiapine therapy, or shortly thereafter, and at 6-month intervals during chronic therapy.

QT Prolongation

QT prolongation reported.

Avoid quetiapine in patient receiving concomitant class IA antiarrhythmics (e.g., quinidine, procainamide), class III antiarrhythmics (e.g., amiodarone, sotalol), antipsychotic agents (e.g., ziprasidone, chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin), or other classes of agents known to prolong the QT interval (e.g., pentamidine, methadone).

Avoid quetiapine in situations where the risk of torsades de pointes and/or sudden death is increased, including in patients with low potassium or magnesium levels, a history of cardiac arrhythmias such as bradycardia or those concomitantly receiving other drugs that prolong the QTc interval, and in patients with congenital QT-interval prolongation.

Exercise caution in patients with an increased risk of QT prolongation (e.g., cardiovascular disease, family history of QT prolongation, geriatric patients, congestive heart failure, and cardiac hypertrophy.

Seizures

Possible risk of seizures; use with caution in patients with a history of seizures or with conditions known to lower the seizure threshold (e.g., dementia of the Alzheimer’s type, geriatric patients).

Hypothyroidism

Hypothyroidism possible. Check both TSH and free T4, and provide a clinical assessment at baseline and during follow-up.

Hyperprolactinemia

Elevated prolactin concentrations reported. Chronic hyperprolactinemia associated with hypogonadism can lead to decreased bone density in male and female patients.

Potential for Cognitive and Motor Impairment

Somnolence commonly reported, especially during initial dosage titration period. Potential impairment of judgment, thinking, or motor skills.

Body Temperature Regulation

Disruption of ability to reduce core body temperature possible; use with caution in patients exposed to conditions that may contribute to an elevation in core body temperature (e.g., dehydration, extreme heat, strenuous exercise, concomitant use of anticholinergic agents).

Dysphagia

Esophageal dysmotility and aspiration possible; use with caution in patients at risk for aspiration pneumonia (e.g., geriatric patients, those with advanced Alzheimer’s dementia).

Discontinuation Syndrome

Acute withdrawal symptoms such as insomnia, nausea, and vomiting reported after abrupt cessation of antipsychotic agents, including quetiapine. Gradual dosage reduction advised during discontinuation.

Anticholinergic Effects

Use with caution in patients receiving other medications with anticholinergic effects. Constipation, a risk factor for intestinal obstruction, reported. Intestinal obstruction reported, including fatal cases.

Use with caution in patients with a current diagnosis or prior history of urinary retention, clinically significant prostatic hypertrophy, or constipation.

Specific Populations

Pregnancy

Pregnancy exposure registry available; register patients by calling the National Pregnancy Registry for Atypical Antipsychotics at 1-866-961-2388 or online at [Web].

Risk for extrapyramidal and/or withdrawal symptoms (e.g., agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, feeding disorder) in neonates exposed to antipsychotic agents during the third trimester; monitor neonates exhibiting such symptoms. Symptoms were self-limiting in some neonates but varied in severity; some infants required prolonged hospitalization.

Lactation

Distributes into human milk at a relative infant dose <1% of maternal weight-adjusted dosage. No consistent adverse effects reported in infants exposed to drug through breast milk. Effects on milk production not known. Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for quetiapine and the potential for adverse effects on the breastfed infant from exposure to quetiapine through the breast milk or from the mother’s underlying condition.

Females and Males of Reproductive Potential

Can cause increased serum prolactin concentrations, which may lead to a reversible decrease in fertility in females of reproductive potential.

Pediatric Use

Safety and efficacy established in pediatric patients 13–17 years of age with schizophrenia.

Safety and efficacy established in pediatric patients 10–17 years of age with bipolar I disorder.

Safety and efficacy in pediatric patients <13 years of age with schizophrenia not established.

Safety and efficacy in pediatric patients <10 years of age with bipolar mania not established.

Safety and efficacy not established in pediatric patients <18 years of age for maintenance of bipolar disorder. Safety and efficacy not established in pediatric patients <18 years of age for maintenance therapy of schizophrenia.

Safety and efficacy in pediatric patients <18 years of age with bipolar depression not established.

Greater risk of suicidal thinking or behavior (suicidality) occurred during the first few months of antidepressant treatment compared with placebo in children and adolescents with major depressive disorder, obsessive-compulsive disorder (OCD), or other psychiatric disorders based on pooled analyses of 24 short-term, placebo-controlled trials of 9 antidepressant drugs (SSRIs and other antidepressants). No suicides occurred in these pediatric trials. Unclear if risk extends beyond first few months.

Adverse reactions observed in children and adolescents receiving quetiapine in clinical trials were generally similar to those in adults with a few exceptions. Increases in systolic and diastolic blood pressure occurred in children and adolescents but not in adults. Orthostatic hypotension occurred more frequently in adults (47%) compared with children and adolescents (<1%).

Geriatric Use

No substantial differences in safety relative to younger adults, but factors that decrease pharmacokinetic clearance, increase the pharmacodynamic response, or cause poorer tolerance or orthostasis may be present.

Atypical antipsychotics are not approved for the treatment of dementia-related psychosis.

In pooled data analyses, a reduced risk of suicidality was observed in adults ≥65 years of age with antidepressant therapy compared with placebo.

Hepatic Impairment

Increased plasma concentrations expected in patients with hepatic impairment; dosage adjustment may be necessary.

Renal Impairment

Clearance may be decreased in severe renal impairment, but dosage adjustment not necessary.

Common Adverse Effects

Most common adverse effects reported in ≥5% of adults and at a frequency twice that reported among patients receiving placebo in clinical trials include somnolence/sedation, asthenia, lethargy, dizziness, dry mouth, constipation, increased ALT, weight gain, dyspepsia, abdominal pain, postural hypotension, and pharyngitis.

Most common adverse effects reported in ≥5% of children and adolescents and at a frequency twice that reported among patients receiving placebo in clinical trials include somnolence, dizziness, fatigue, increased appetite, nausea, vomiting, dry mouth, tachycardia, and weight gain.

Does Quetiapine interact with my other drugs?

Enter medications to view a detailed interaction report using our Drug Interaction Checker.

Drug Interactions

Metabolized principally by CYP3A4. Does not appear to inhibit CYP1A2, CYP2C9, CYP2C19, CYP2D6, or CYP3A4 in vitro; pharmacokinetic interaction with substrates of these isoenzymes unlikely.

Drugs Affecting Hepatic Microsomal Enzymes

Potent inhibitors or inducers of CYP3A4; potential pharmacokinetic interaction (altered quetiapine metabolism). Quetiapine dosage adjustment recommended with concomitant use.

Drugs that Prolong QT Interval

Possible additive effect on QT-interval prolongation; avoid concomitant use.

Specific Drugs

Drug

Interaction

Comments

Alcohol

Potentiation of cognitive and motor effects of alcohol

Avoid alcohol during therapy with quetiapine

Anticholinergic drugs

Possible increased anticholinergic effects (including constipation and decreased intestinal motility) and disruption of body temperature regulation

Use with caution

Antifungals, azole (e.g., itraconazole, ketoconazole)

Substantial decrease in quetiapine clearance with concomitant use of ketoconazole, resulting in increased peak plasma quetiapine concentrations

Reduce quetiapine dosage to one-sixth of the original dosage during concomitant use

Carbamazepine

Possible increased quetiapine clearance

With chronic use (e.g., longer than 7–14 days), increase the quetiapine dosage by up to 5-fold

Upon discontinuation of carbamazepine, return quetiapine back to original dosage within 7–14 days

Cimetidine

Decreased quetiapine mean clearance

CNS agents

Possible additive CNS effects

Use with caution

Divalproex sodium

Increased peak plasma quetiapine concentrations, with no effect on extent of absorption or mean quetiapine clearance; decreased peak plasma valproic acid concentrations and extent of absorption

Dopamine agonists

Possible antagonistic effects

Fluoxetine

No effect on quetiapine pharmacokinetics

Haloperidol

No effect on quetiapine pharmacokinetics

Hypotensive agents

Possible potentiation of hypotensive effects

Use with caution

Imipramine

No effect on steady-state quetiapine pharmacokinetics

Levodopa

Possible antagonistic effects

Lithium

No effect on lithium pharmacokinetics

Lorazepam

Decreased lorazepam clearance

Nefazodone

Potential for increased quetiapine concentrations

Reduce quetiapine dosage to one-sixth of the original dosage during concomitant use

Phenytoin

Substantially increased quetiapine clearance

With chronic use (e.g., longer than 7–14 days), increase the quetiapine dosage by up to 5-fold

Upon discontinuation of phenytoin, return quetiapine back to original dosage within 7–14 days

Rifampin

Possible increased quetiapine clearance

With chronic use (e.g., longer than 7–14 days), increase the quetiapine dosage by up to 5-fold

Upon discontinuation of rifampin, return quetiapine back to original dosage within 7–14 days

Risperidone

No effect on quetiapine pharmacokinetics

Ritonavir

Potential for increased quetiapine concentrations

Reduce the quetiapine dosage to one-sixth of the original dosage during concomitant use

Smoking

No effect on oral clearance of quetiapine

St. John's wort (Hypericum perforatum)

Possible increased quetiapine clearance

With chronic use (e.g., longer than 7–14 days), increase the quetiapine dosage by up to 5-fold

Upon discontinuation of St. John’s wort, return quetiapine back to original dosage within 7–14 days

Thioridazine

Increased quetiapine clearance by 65%

Possible additive effect on QT-interval prolongation

Avoid concomitant use

QUEtiapine Pharmacokinetics

Absorption

Bioavailability

Conventional tablets: Rapidly absorbed after oral administration, with peak plasma concentrations attained within 1.5 hours.

Extended-release tablets: Peak plasma concentrations attained in 6 hours.

Extended-release tablets at steady state comparable bioavailability to equivalent total daily dose of conventional tablets administered in 2 divided doses.

Food

Bioavailability of conventional tablets marginally affected by food.

Significant increases in quetiapine exposure when extended-release tablets are administered with a high-fat meal (approximately 800–1000 calories); exposure not significantly altered when taken with a light meal (approximately 300 calories).

Distribution

Extent

Widely distributed throughout the body.

Distributed into human milk.

Plasma Protein Binding

83%.

Elimination

Metabolism

Extensively metabolized to inactive metabolites, principally via CYP3A4.

Elimination Route

Excreted in urine (73%) and feces (20%), with <1% of the drug excreted unchanged.

Half-life

Conventional tablets: Approximately 6 hours.

Extended-release tablets: Approximately 7 hours for quetiapine, 12 hours for norquetiapine (active metabolite).

Special Populations

In patients with hepatic impairment, clearance is 30% lower than in normal individuals; AUC and peak plasma concentrations were 3 times higher in 2 out of 8 hepatically-impaired patients than in healthy individuals.

In patients with severe renal impairment (Clcr 10–30 mL/minute), clearance may be reduced by 25% compared with healthy individuals; however, plasma concentrations in patients with renal impairment were within the range of those seen in healthy patients.

In geriatric patients, clearance is decreased by 40% compared with younger patients.

In pediatric patients, AUC and peak plasma concentrations are 41% and 39% lower, respectively, compared with adults.

Stability

Storage

Oral

Tablets (immediate- and extended-release)

25°C (may be exposed to 15–30°C).

Actions

Advice to Patients

Additional Information

The American Society of Health-System Pharmacists, Inc. represents that the information provided in the accompanying monograph was formulated with a reasonable standard of care, and in conformity with professional standards in the field. Readers are advised that decisions regarding use of drugs are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and that the information contained in the monograph is provided for informational purposes only. The manufacturer’s labeling should be consulted for more detailed information. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information contained in the monograph is not a substitute for medical care.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

QUEtiapine Fumarate

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Tablets, film-coated

25 mg (of quetiapine)*

Quetiapine Fumarate Tablets

SEROquel

AstraZeneca

50 mg (of quetiapine)*

Quetiapine Fumarate Tablets

SEROquel

AstraZeneca

100 mg (of quetiapine)*

Quetiapine Fumarate Tablets

SEROquel

AstraZeneca

150 mg (of quetiapine)*

Quetiapine Fumarate Tablets

200 mg (of quetiapine)*

Quetiapine Fumarate Tablets

SEROquel

AstraZeneca

300 mg (of quetiapine)*

Quetiapine Fumarate Tablets

SEROquel

AstraZeneca

400 mg (of quetiapine)*

Quetiapine Fumarate Tablets

SEROquel

AstraZeneca

Tablets, Extended-release

50 mg (of quetiapine)*

Quetiapine Fumarate Extended-release Tablets

SEROquel XR

150 mg (of quetiapine)*

Quetiapine Fumarate Extended-release Tablets

SEROquel XR

200 mg (of quetiapine)*

Quetiapine Fumarate Extended-release Tablets

SEROquel XR

300 mg (of quetiapine)*

Quetiapine Fumarate Extended-release Tablets

SEROquel XR

400 mg (of quetiapine)*

Quetiapine Fumarate Extended-release Tablets

SEROquel XR

AHFS DI Essentials™. © Copyright 2025, Selected Revisions July 10, 2025. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.

† Off-label: Use is not currently included in the labeling approved by the US Food and Drug Administration.

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