Quetiapine (Seroquel) is an atypical antipsychotic medicine that is used in the treatment of patients with schizophrenia, agitation, delirium, and bipolar disorder.

Quetiapine Uses:

• Bipolar disorder:

  • It is indicated for
    • Acute treatment of manic (both immediate release and ER) or mixed (ER only) episodes
    • Acute hypomanic episodes (off-label) associated with bipolar I disorder, both as monotherapy and along with anti-manic therapy;
    • Maintenance treatment of bipolar I disorder, as monotherapy (off-label) or along with anti-manic therapy
    • Acute treatment of bipolar major depression, as monotherapy.

• Major depressive disorder (unipolar) (ER only):

  • It is indicated for adjunctive therapy in patients with an inadequate response to antidepressants for the treatment of major depressive disorder.

• Schizophrenia:

  • It is indicated for treatment of schizophrenia.

• Off Label Use of Quetiapine in Adults:

  • Agitation and/or delirium, intensive care unit (alternative agent);
  • Delusional infestation (delusional parasitosis);
  • Generalized anxiety disorder (alternative agent);
  • Major depressive disorder (unipolar), monotherapy (alternative agent);
  • Obsessive-compulsive disorder, treatment-resistant (augmentation);
  • Posttraumatic stress disorder, adjunct to antidepressants or monotherapy (alternative agent);
  • Psychosis/agitation associated with dementia, severe or refractory (alternative agent);
  • Psychosis in Parkinson disease

Note: Quetiapine is available as immediate-release and 24-hour ER tablets; to convert between formulations, see "Dosing Conversion" below.

Quetiapine (Seroquel) Dose in the treatment of Agitation and/or delirium in the ICU (alternative agent) (off-label):

Note: Non-pharmacologic interventions and treatment of underlying conditions are initial steps to prevent and manage delirium. Antipsychotics may be used as short-term adjunctive treatment if distressing symptoms (eg, agitation, anxiety) are present

• Immediate release:

  • Oral or via NG tube: Initial: 50 mg twice a day; dose can be increased by 100 mg/day to a maximum dose of 400 mg/day.
  • In adverse effects sensitive patients, initial lowering dose of 12.5 mg twice daily or 25 to 50 mg at bedtime can be given and gradually increase (eg, in increments of 25 mg/day) based on response and tolerability

Quetiapine (Seroquel) Dose in the treatment of Bipolar disorder:

• Acute manic episodes (labeled use), mixed episodes (labeled use [extended release]; off label use [immediate release]), and acute hypomania (off-label) (monotherapy or adjunct to anti-manic therapy):

  • Immediate release:

    • Oral: Initial: 100 - 200 mg once a day at bedtime or in 2 divided doses on day 1, then increase by 100 mg/day (divided twice a day or as single dose at bedtime) up to maximum dose of 400 mg/day by day 4;
    • Further dose can be increased and tolerability with increasing dose of ≤200 mg/day
    • Maximum dose: 800 mg/day
    • According to recommendation of some experts, some patients needs dose up to 1.2g/day for optimal response

  • Extended release:

    • Oral: Initial: 300 mg once a day on day 1; increase to 600 mg once a day on day 2, then adjust dose according to response.
    • Maximum dose: 800 mg once a day
    • According to recommendation of some experts, some patients needs dose upto 1.2g/day for optimal response

• Bipolar major depression (monotherapy [labeled use] or in combination with anti-manic therapy [off-label]):

  • Immediate release, Extended release:

    • Oral: Initial: 50 mg once a day at bedtime; increase to 100 mg once a day on day 2, further increase by 50 - 100 mg/day to reach a usual target dose of 300 mg once a day by day 4 - 7
    • Maximum dose: 300 mg/day
    • According to recommendation of some experts, some patients needs dose upto 800mg/day for optimal response

• Maintenance treatment (monotherapy [off-label use] or adjunct to antimanic therapy [labeled use]):

  • Immediate release, Extended release:

    • Oral: Dose and combination that was used to achieve control of the acute episode should be continued
    • Maximum dose: 800 mg/day
    • Patients requiring higher doses up to 1.2 g/day to achieve remission, this dose is initially continued for maintenance if tolerated

Quetiapine (Seroquel) Dose in the treatment of Delusional infestation (delusional parasitosis) (off-label):

• Immediate release:

  • Oral: Initial: 12.5 - 50 mg at bedtime; gradually increase dose based on response and tolerability every 3 - 7 days up to 200 - 300 mg at bedtime or in divided doses.
  • Continue treatment for at least 3 months before attempting to decrease dose.
  • According to the recommendation of some experts target a dose of 200mg/day and consider discontinuation as soon as 1 month after response

Quetiapine (Seroquel) Dose as an alternative agent in the treatment of Generalized anxiety disorder (adjunct to antidepressants) (off-label):

• Immediate release, Extended release:

  • Oral: Initial: 25 mg once a day (immediate release only) to 50 mg once a day;
  • Its dose can be increased gradually every ≥7 days to the usual dose range of 50-200 mg/day
  • Maximum  dose recommended: 300 mg/day
  • For the ER tablet, increasing the dose to 100 or 150 mg on day 3 or 4 of therapy may be appropriate for patients with severe symptoms.

Note: May also be used for monotherapy in patients who have not responded to or do not tolerate antidepressants and other first-line agents.

Quetiapine (Seroquel) Dosing in treatment of unipolar major depressive disorder:

• Dose in the treatment of Non-psychotic depression as an adjunct for insufficient response to antidepressants (labeled use [extended release];
• off-label use [immediate release]) or psychotic depression in combination with an antidepressant (off-label):

  • Immediate release, Extended release:

    • Oral: Initial: 50 mg once a day on days 1 and 2; increase to 150 mg once a day on day 3.
    • Usual dosage range: 150 - 300 mg/day
    • however, doses up to 600 mg/day in psychotic depression may be required and tolerated

• Dose as alternative agent in the treatment of Non-psychotic depression, monotherapy (off-label):

  • Immediate release, Extended release:

    • Oral: Initial: 50 mg once a day; gradually increase the dose upto 300 mg/day according to response and tolerability

Quetiapine (Seroquel) Dose to augment the antidepressant effect in patients with treatment-resistant Obsessive-compulsive disorder (off-label):

• Immediate release:

  • Oral: Initial: 25 - 50 mg once a day; gradually increase the dose of 25-100 mg every 2-3 weeks up to 400 mg/day (according to response and tolerability)

Quetiapine (Seroquel) Dose as an alternative agent in the treatment of Post-traumatic stress disorder (adjunct to antidepressants or monotherapy) (off-label):

• Immediate release:

  • Oral: Initial: 25 mg once a day at bedtime; dose can be increased by 25 mg every 1 - 2 days up to 100 mg at bedtime by the end of week 1;
  • Dose further can be increased  by 25mg/day up to 100mg/week (according to clinical response and tolerability)
  • Average dose in clinical trials: 100 - 336 mg/day (range: 25 to 800 mg/day)
  • According to recommendation of some experts dose can gradually be increased
  • Some experts suggest gradually increasing dose according to response and tolerability in increments of 50 mg/week up to a total daily dose of 400 mg

Quetiapine (Seroquel) Dose as an alternative agent in the treatment of severe or refractory psychosis and agitation associated with dementia (off-label):

Note: For short-term adjunctive use while addressing underlying cause(s) of severe symptoms:

• Immediate release:

  • Oral: Initial: 25 mg at bedtime; dose can be gradually increased (eg, weekly) based according to response and tolerability up to 75 mg twice a day
  • Once adequate response is achieved, try to taper and withdraw therapy within 4 months of initiation.

Quetiapine (Seroquel) Dose in the treatment of Psychosis in Parkinson disease (off-label):

• Immediate release:

  • Oral: Initial: 12.5 - 25 mg at bedtime; dose can be increased by 12.5 to 25 mg every 1 - 2 weeks according to clinical response and tolerability
  • Average dose in studies ranged from 40 - 185 mg/day
  • According to recommendations of some experts dose can be increased up to 100mg at bed time and then add morning dose if required to control the symptoms upto maximum dose of 100 mg/day

Quetiapine (Seroquel) Dose in the treatment of Schizophrenia:

• Immediate release:

  • Oral: Initial: 25 mg twice a day; dose can be increased by 25 - 50 mg/day in 2 or 3 divided doses on days 2 and 3 and increase further to a target dose of 300 - 400 mg/day by day 4.
  • further dose can be increased by 50 - 100 mg/day every ≥2 days.
  • Acute therapy usual dosage range: 150 - 750 mg/day.
  • Maintenance therapy usual dosage range: 400 - 800 mg/day
  • Maximum dose: 800 mg/day.

• Extended release:

  • Oral: Initial: 300 mg once a day; dose can be increased by 300 mg/day every ≥1 day.
  • Usual dosage range: 400 - 800 mg once daily
  • Maximum dose: 800 mg/day.

Note: Doses up to 1.6 g/day have been studied but doses >800 mg/day did not provide  greater efficacy, may produce greater adverse effects, and are generally not recommended.

• Dosing conversion:

  • To convert patients between immediate-release and ER tablets, administer the equivalent total daily dose.
  • Administer immediate-release daily dose in 1 to 3 divided doses and extended release once a day; individual dosage adjustments may be necessary.

  • Re-initiation of treatment:

    • Patients who have discontinued therapy for >1 week should generally be re-titrated using the initial dosing schedule
    • patients who have discontinued <1 week can generally be reinitiated on their previous maintenance dose.

• Dosage adjustment for concomitant therapy:

  • Concomitant use with a strong CYP3A4 inhibitor (eg, voriconazole, itraconazole, ritonavir, nefazodone):

    • Avoid combination if an appropriate noninteracting alternative is available
    • Otherwise decrease quetiapine to one-sixth of the original dose;
    • when strong CYP3A4 inhibitor is discontinued, increase quetiapine by 6-fold.
    • Some combinations are considered contraindicated or not recommended.

  • Concomitant use with a strong CYP3A4 inducer (eg, phenytoin, carbamazepine, rifampin, St John's wort):

    • Avoid combination if an appropriate noninteracting alternative is available
    • Otherwise increase quetiapine up to 5-fold of the original dose when combined with chronic treatment (>7 - 14 days) of a strong CYP3A4 inducer
    • After discontinuation of strong CYP3A4 inducer, decrease to the original dose within 7 - 14 days.

• Discontinuation of therapy:

  • Dose should be gradually reduced to avoid withdrawal symptoms (ie, insomnia, headache, and GI symptoms) unless discontinuation is due to significant adverse effects.
  • For discontinuation of chronic antipsychotic therapy in patients with schizophrenia or bipolar disorder, dose should be decreased very lowly or gradually over months to years with close monitoring is suggested to allow for detection of prodromal symptoms of disease recurrence

• Switching antipsychotics: Limited data available; optimal universal strategy is unknown. Strategies include:

  • Cross-titration
    • Gradually discontinuing the first antipsychotic while gradually increasing the new antipsychotic and
  • Abrupt change:
    • Abrupt change (abruptly discontinuing the first antipsychotic and either increasing the new antipsychotic gradually or starting it at a treatment dose).
  • Overlap:
    • In schizophrenic patients who are at high risk of relapse, continue the current medications at full dose as the new medication is increased
    • once the new medication is at therapeutic dose, the first medication is gradually decreased and discontinued over 1 - 2 weeks

According to recommendation of some experts and  clinical experience, cross-titration and overlap approaches are preferred rather than abrupt change.

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Quetiapine Dose in Children:

Quetiapine (Seroquel) Dose in the treatment of Bipolar disorder, mania or mixed episodes:

• Children and Adolescents ≥10 years: Oral:

  • Immediate-release tablet:

    • Initial: 25 mg twice a day on day 1; increase to 50 mg twice a day on day 2, then 100 mg twice a day on day 3, then 150 mg twice a day on day 4, then continue at the target dose of 200 mg twice a day beginning on day 5.
    • Doses further can be increased according to clinical response and tolerability by ≤100 mg/day up to 300 mg twice a day. (however no extra benefit seen with 300 vs 200 twice a day
    • Usual dosage range: 200 - 300 mg twice a day
    • Maximum daily dose: 600 mg/day.
    • Total daily doses may also be divided into 3 doses per day

  • Extended-release tablet:

    • Initial: 50 mg once a day on day 1; increase to 100 mg once a day on day 2, then increase in 100 mg/day increments each day until a target dose of 400 mg once a day is reached on day 5.
    • Usual dosage range: 400 - 600 mg once a day
    • Maximum daily dose: 600 mg/day

  • Switching from immediate release to extended release:

    • To convert patients between immediate-release and ER tablets, administer the equivalent total daily dose.

Quetiapine (Seroquel) Dose in the treatment of Schizophrenia:

• Adolescents: Oral:

  • Immediate-release tablet:

    • Initial: 25 mg twice a day on day 1; increase to 50 mg twice a day on day 2, 100 mg twice a day on day 3, then 150 mg twice a day on day 4, then continue at a target dose of 200 mg twice a day beginning on day 5.
    • Dose can be increased by ≤100 mg/day up to 400mg twice a day
    • However, no additional benefit observed with 400 mg twice a day vs 200 mg twice a day.
    • Usual dosage range: 200 - 400 mg twice a day
    • Maximum daily dose: 800 mg/day.
    • Total daily doses may also be divided into 3 doses per day

  • Extended-release tablet:

    • Initial: 50 mg once a day on day 1; increase to 100 mg once a day on day 2, then increase in 100 mg/day increments each day until a target dose of 400 mg once daily is reached on day 5.
    • Usual dosage range: 400 - 800 mg once a day
    • Maximum daily dose: 800 mg/day

  • Switching from immediate release to extended release:

    • To convert patients between immediate-release and ER tablets, administer the equivalent total daily dose.

  • Dosing conversion:

    • Administer immediate release 1 - 3 times a day and extended release once a day; individual dosage adjustments may be required.
  • Re-initiation of treatment:
    • Patients who have discontinued therapy for >1 week should generally be re-titrated using the initial dosing schedule
    • patients who have discontinued <1 week can generally be reinitiated on their previous maintenance dose.

  • Dosage adjustment for concomitant therapy:

    • Children ≥10 years and Adolescents:

      • Concomitant use with a strong CYP3A4 inhibitor (eg, ketoconazole, itraconazole, indinavir, ritonavir, nefazodone):
        • Avoid combination if an appropriate noninteracting alternative is available
        • Otherwise decrease quetiapine to one-sixth of the original dose;
        • when strong CYP3A4 inhibitor is discontinued, increase quetiapine by 6-fold.
        • Some combinations are considered contraindicated or not recommended.
      • Concomitant use with a strong CYP3A4 inducer (eg, phenytoin, carbamazepine, rifampin, St. John's wort):
      • Increase quetiapine up to 5-fold of the original dose when combined with chronic treatment (>7 - 14 days) of a strong CYP3A4 inducer
      • After discontinuation of a strong CYP3A4 inducer, decrease to the original dose within 7 - 14 days.

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Quetiapine Use in Pregnancy & lactation

Quetiapine (Seroquel) Pregnancy Risk Category: C

• Quetiapine and its metabolite cross the placenta.
• Use in the third trimester may lead to extrapyramidal and/or withdrawal symptoms in the newborn, such as agitation, feeding difficulties, and hypotonia, which may resolve spontaneously or require hospitalization.
• Patients should notify healthcare providers if pregnant or planning pregnancy within 12 weeks of receiving an IM injection.
• Antipsychotics during pregnancy should involve a multidisciplinary approach with individualized therapy guided by mental health and obstetric professionals.
• Limited safety data exist for atypical antipsychotics in pregnancy, and routine use is not recommended.
• Accidental exposure to antipsychotics during pregnancy may warrant continuation rather than switching agents, considering the risk-benefit ratio.
• Preferential use of alternatives to risperidone is advised if initiating treatment during pregnancy.
• Quetiapine may induce hyperprolactinemia, potentially reducing fertility.

Breastfeeding:

• Quetiapine is excreted in breast milk, with a relative infant dose (RID) of 0.43%, considered within the acceptable range (<10%).
• Peak breast milk concentration occurs approximately one hour after maternal dosing.
• Adverse events in breastfeeding infants have not been reported, but monitoring for lethargy, appetite changes, irritability, and sleep disturbances during the first month is recommended.
• The manufacturer advises weighing the risks to the infant against the benefits of treatment for the mother.
• Quetiapine may be used in nursing women if an antipsychotic is necessary

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Quetiapine (Seroquel) Dose in Kidney Disease: 

No dosage adjustment is required. 

Quetiapine (Seroquel) Dose in Liver disease:

• Immediate-release tablet: Initial: 25 mg a day, increase dose by 25 - 50 mg daily to effective dose (according to clinical response and tolerability)
• Extended-release tablet: Initial: 50 mg once a day; increase dose by 50 mg once  a day to effective dose, based on individual clinical response and tolerability

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Common Side Effects of Quetiapine (Seroquel):

• Cardiovascular:

  • Increased Diastolic Blood Pressure
  • Increased Systolic Blood Pressure
  • Tachycardia

• Central Nervous System:

  • Drowsiness
  • Headache
  • Agitation
  • Dizziness
  • Fatigue
  • Extrapyramidal Reaction

• Endocrine & Metabolic:

  • Weight Gain
  • Increased Serum Triglycerides
  • Decreased HDL Cholesterol
  • Total Cholesterol Increased
  • Increased LDL Cholesterol
  • Hyperglycemia

• Gastrointestinal:

  • Xerostomia
  • Increased Appetite
  • Constipation

Less Common Side Effects Of Quetiapine (Seroquel):

• Cardiovascular:

  • Orthostatic Hypotension
  • Palpitations
  • Peripheral Edema
  • Increased Heart Rate
  • Hypotension
  • Hypertension
  • Hypertension
  • Syncope

• Central Nervous System:

  • Pain
  • Drug-Induced Parkinson Disease
  • Irritability
  • Lethargy
  • Dysarthria
  • Akathisia
  • Hypertonia
  • Twitching
  • Anxiety
  • Abnormal Dreams
  • Depression
  • Hypersomnia
  • Paresthesia
  • Aggressive Behavior
  • Dystonic Reaction
  • Abnormality In Thinking
  • Ataxia
  • Confusion
  • Decreased Mental Acuity
  • Disorientation
  • Disturbance In Attention
  • Falling
  • Hypoesthesia
  • Lack Of Concentration
  • Migraine
  • Restless Leg Syndrome
  • Restlessness
  • Vertigo

• Dermatologic:

  • Skin Rash
  • Acne Vulgaris
  • Diaphoresis
  • Hyperhidrosis
  • Pallor

• Endocrine & Metabolic:

  • Hyperprolactinemia
  • Increased Thirst
  • Decreased Libido
  • Hypothyroidism

• Gastrointestinal:

  • Nausea
  • Vomiting
  • Dyspepsia
  • Abdominal Pain
  • Diarrhea
  • Viral Gastroenteritis
  • Toothache
  • Anorexia
  • Periodontal Abscess
  • Decreased Appetite
  • Dysphagia
  • Gastroenteritis
  • Gastroesophageal Reflux Disease
• Genitourinary:
  • Pollakiuria
  • Urinary Tract Infection

• Hematologic & Oncologic:

  • Neutropenia
  • Leukopenia

• Hepatic:

  • Increased Serum Transaminases

• Hypersensitivity:

  • Seasonal Allergy

• Neuromuscular & Skeletal:

  • Asthenia
  • Tremor
  • Back Pain
  • Dyskinesia
  • Arthralgia
  • Muscle Rigidity
  • Stiffness
  • Muscle Spasm
  • Limb Pain
  • Myalgia
  • Neck Pain

• Ophthalmic:

  • Blurred Vision
  • Amblyopia

• Otic:

  • Otalgia

• Respiratory:

  • Pharyngitis
  • Nasal Congestion
  • Rhinitis
  • Epistaxis
  • Upper Respiratory Tract Infection
  • Paranasal Sinus Congestion
  • Cough
  • Dyspnea
  • Sinus Headache
  • Sinusitis
  • Influenza

• Miscellaneous:

  • Fever

Contraindications to Quetiapine (Seroquel):

  Hypersensitivity to quetiapine and any component of the formulation

Warnings and precautions Anticholinergic effects

• It can cause anticholinergic reactions in elderly patients, such as constipation, xerostomia and blurred vision.
• Patients with reduced gastrointestinal motility, urinary retention, paralytic ileus or visual impairments should not use it.
• Quetiapine is a lower-potency antipsychotic than other antipsychotics.

Blood dyscrasias:

• Leukopenia and neutropenia have been reported.
• If there are risk factors, such as low WBC or a history of drug-induced hemorhage, periodic blood count assessments should be performed.
• Stop treatment at the first sign of blood dyscrasias, or if the absolute neutrophil count is 1,000/mm3.

Cataracts

• Studies on animals show that it is associated with cataract formation.
• Lens changes can occur in the eyes after long-term treatment
• It is recommended to have a slit-lamp examination at the beginning of therapy and every six months.

CNS depression:

• CNS depression can result, which can affect mental or physical abilities.
• It is important to warn patients about tasks that require mental alertness, such as driving or operating machinery.

Esophageal dysmotility/Aspiration:

• Aspiration and esophageal dysmotility have been linked to antipsychotic use.
• Your risk of developing it increases as you age.
• Patients at high risk of aspiration pneumonia (i.e. Alzheimer disease) should be treated with caution, especially patients over 75 years.

Extrapyramidal symptoms:

• It can also cause extrapyramidal signs (EPS), such as pseudo-parkinsonism and acute dystonic reactions.
• Higher doses of antipsychotics and older patients are associated with greater risk of developing dystonia.
• With a higher risk of tardive dyskinesia in older age and females with postmenopausal status, Parkinson's disease, pseudo-parkinsonism symptoms and affective disorders, other medical conditions such as diabetes, brain damage, alcoholism, poor response to treatment, and high doses antipsychotics, is associated with older age.
• Stop treating tardive dyskinesia symptoms and signs.

Falls

• Use of it can increase the risk of falls among seniors due to somnolence and postural dizziness.
• Hyperglycemia:
  • Hyperglycemia can be caused by the use of Atypical antipsychotics. It can also lead to hyperosmolar coma or ketoacidosis.
  • Patients with diabetes and other disorders of glucose regulation should not use it. Monitor for signs of worsening glucose control.
  • Quetiapine has a very low risk of hyperglycemia.
• Hyperlipidemia:
  • There have been increases in cholesterol and triglycerides.
  • Patients with an abnormal lipid profile should be cautious.
  • The risk of metabolic adverse effects, including hyperlipidemia, with quetiapine has a moderate rate of incidence compared to other antipsychotics.
• Hyperprolactinemia:
  • Hyperprolactinemia may increase prolactin levels in breast cancer patients.
• Hypersensitivity
  • Anaphylactic reactions have been reported.
• Hypothyroidism:
  • Thyroid levels may be affected by thyroid doses. This includes cases that require thyroid replacement therapy.
  • In almost all cases, thyroid effects were reversed after discontinuation.
  • At baseline and following-up, measure TSH and free T, together with a clinical assessment to determine thyroid status. TSH measurement alone may not be accurate. The exact mechanism of quetiapine’s effect on the thyroid is unknown.
• Neuroleptic malignant syndrome (NMS):
  • You may experience neuroleptic malignant Syndrome (NMS) when you use it. Monitor for changes in mental status, fever, rigidity, and/or autonomic instability.
  • Quitiapine has been used in rare cases.
• Orthostatic hypotension
  • May cause orthostatic hypotension; use with caution in patients at risk of this effect or in those who would not tolerate transient hypotensive episodes (cerebrovascular disease, cardiovascular disease, dehydration, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia).
  • You can reduce the risk by starting with a low dose (e.g., immediate release 25mg twice daily); hypotension may occur during titration. In this case, it is recommended to return to the original dose as per the titration schedule.
• Extension of QT
  • QT prolongation has been reported with the use of quetiapine. Postmarketing reports also indicate that this was seen in patients who had a concomitant illness or were taking concomitant therapies known to increase QT intervals or cause electrolyte imbalance.
  • Patients at higher risk of torsade des pointes/sudden deaths should be advised to avoid use (eg, hypokalemia and hypomagnesemia; history of cardiac arrhythmias; congenital prolongation QT interval; concomitant medication with QTc interval prolonging properties).
  • Patients at higher risk for QT prolongation (eg., heart disease, heart failure and cardiac hypertrophy), elderly people, and families with a history of QT extension should be used with caution.
• Temperature regulation
  • Its use can cause impaired core temperature regulation. Be careful with heat exposure, strenuous exercise, dehydration, and any concomitant anticholinergic medication.
• Weight loss
  • Significant weight gain may be caused by antipsychotic therapy. This has been confirmed.
  • Check your waist circumference and your BMI.
  • Quetiapine has a moderate risk of weight gain compared to other antipsychotics.
• Dementia: [US Boxed Warning]
  • The risk of death increases if dementia-related psychosis is treated with antipsychotics as opposed to placebo
  • The majority of deaths were either from cardiovascular disease (eg heart failure, sudden death, etc.) or infectious diseases (eg pneumonia).
  • Avoid Lewy body dementia and Parkinson disease dementia. There are more severe and immediate adverse effects and a higher sensitivity to extrapyramidal effects. It can also cause irreversible cognitive decline or death.
  • Quetiapine has not been approved to treat dementia-related psychosis.
• Hepatic impairment
  • Avoid use in patients with hepatic impairment or disease. It may increase transaminases (primarily ALT; temporary, reversible).
  • Recommendations for adjustment:
• Renal impairment
  • Patients with kidney disease should be cautious; our experience is limited.
• Seizures:
  • Patients at high risk of seizures should be treated with caution.
    • History of seizures
    • Head trauma
    • brain damage
    • Alcoholism
    • Concurrent therapy may include medications that can lower the seizure threshold.
  • Due to the increased prevalence of predisposing factors, elderly patients could be at greater risk for seizures.

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Monitoring parameters:

• Mental status
• vital signs
• Blood pressure
  • Baseline then every 3 months after start of antipsychotics, then yearly, particularly in children and adolescents)
• Weight, height, BMI, waist circumference
  • Baseline; repeat at 4, 8, and 12 weeks after start of therapy, then quarterly
  • If weight gain ≥5%, switch to different antipsychotics
• CBC: frequently during the first few months of therapy in patients with cytopenias
• Electrolytes
• Liver function (annually and as clinically indicated)
• TSH and thyroid clinical assessment (baseline and follow-up)
• Fasting plasma glucose level/HbA1C
  • Baseline; repeat 3 months after starting antipsychotic, then yearly
• Fasting lipid panel
  • Baseline; repeat 3 months after starting antipsychotic; if LDL level is normal, repeat at 2-5 year intervals,
• Menstrual changes, libido, development of galactorrhea, erectile and ejaculatory function
  • At every visit for the first 12 weeks after start of antipsychotic until the dose is stable, then yearly
• Abnormal involuntary movements or parkinsonian signs
  • Baseline then repeat weekly until dose stabilised for at least 2 weeks after introduction and for 2 weeks after any significant dose increase
• Tardive dyskinesia
  • Every 12 months; high-risk patients every 6 months
• Lens examination, such as a slit-lamp exam, on initiation of therapy and every 6 months is recommended by manufacturer; alternatively, examine patient with proper history and eye examination in patients >40 years or every 2 years in younger patients.

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How to administer Quetiapine (Seroquel)?

Oral: Immediate-release tablet: Can be taken with or with out food. Extended-release tablet: Take with food or with a light meal (≤300 calories), preferably in the evening. Swallow the tablet whole; do not break, crush, or chew. Nasogastric/enteral tube (off-label route):

• Flush with 25 mL of sterile water
• Crush dose using immediate-release formulation, mix in 10 mL water and administer via NG/enteral tube
• Follow with a 50 mL flush of sterile water

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Mechanism of action of Quetiapine (Seroquel):

General Information

• Quetiapine is a dibenzothiazepine antipsychotic.
• It inhibits multiple neurotransmitter and reward receptors, including:
  • Dopamine receptors: D1 and D2
  • Serotonin receptors: 5-HT1A and 5-HT2
  • Histamine receptor: H1
• Lacks affinity for benzodiazepine and cholinergic muscarinic receptors.

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Absorption

• Rapid absorption after oral administration.
• Impact of meals:
  • High-fat meals (880–1000 calories):
    • Increase Cₘₐₓ by 8%
    • Increase AUC by 22% (for quetiapine XR)
  • Light meals (390 calories): No effect.
• Pediatric pharmacokinetics (ages 10–17 years):
  • Lower AUC and Cₘₐₓ for the parent compound compared to adults (weight-adjusted).
  • Active metabolite pharmacokinetics are comparable to adults.

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Distribution

• Volume of distribution (Vᵈ): 10 ± 4 L/kg
• Protein binding (plasma): 83%

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Metabolism

• Primary site: Hepatic metabolism.
• Enzyme: CYP3A4
• Metabolites:
  • Active: N-desalkyl quetiapine
  • Inactive: Sulfoxide metabolite (major) and parent acid metabolite
• Bioavailability: 100% (relative to oral solution).

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Elimination

• Half-life elimination:
  • Children and adolescents (12–17 years):
    • Immediate-release quetiapine: ~5.3 hours
  • Adults:
    • Immediate-release quetiapine: ~6 hours
    • Extended-release quetiapine: ~7 hours
    • N-desalkyl quetiapine (metabolite): ~12 hours
• Time to peak plasma concentration:
  • Children and adolescents (12–17 years): 0.5–3 hours (immediate release).
  • Adults:
    • Immediate-release: 1.5 hours
    • Extended-release: 6 hours
• Excretion:
  • Urine: 73% (as metabolites); <1% unchanged drug.
  • Feces: 20%.

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International Brand Names of Quetiapine:

• SEROquel
• SEROquel XR
• Abbott-QUEtiapine
• ACCEL-QUEtiapine
• ACT QUEtiapine
• AG-Quetiapine
• APOQUEtiapine
• APO-QUEtiapine XR
• Auro-QUEtiapine
• BIO-QUEtiapine
• DOM-QUEtiapine
• JAMPQUEtiapine
• Mar-QUEtiapine
• MINT-QUEtiapine
• MYLAN-QUEtiapine
• NAT-QUEtiapine
• PHL QUEtiapine
• PMS-QUEtiapine
• Priva-QUEtiapine
• PRO-QUEtiapine
• RAN-QUEtiapine
• RIVAQUEtiapine
• SANDOZ QUEtiapine
• SANDOZ QUEtiapine XRT
• SEROquel
• SEROquel XR
• TEVAQUEtiapine
• TEVA-QUEtiapine XR
• VAN-QUEtiapine
• Alvoquel
• Aretaeus
• Biatrix
• Bipresso
• Biquelle XL
• Cacepin
• Calm-EZ
• Catepsin
• Delucon
• Ebesque XL
• Edagan
• Geroquel
• Gofyl
• Hedonin
• Hiloca
• Keepquet
• Kesaquil
• Ketilept
• Ketipinor
• Kitapen
• Kventiax
• Limus
• Mintreleq XL
• Neutapin
• Ovex
• Psyquel
• Q-Win
• Qmax
• Qtipine
• Quantia
• Quentiax
• Querok
• Quetapel
• Quetapin
• Quetiap RD
• Quetiazic
• Quetidin
• Quetinil
• Quetiron
• Quety
• Quiet
• Quitcool
• Qurax
• Qutero
• Qutiapine
• Qutipin
• Rezal XR
• Sequase
• Serogen
• Seroquel
• Seroquel IR
• Seroquel Prolong
• Seroquel SR
• Seroquel XR
• Seroquet
• Serotia
• Serroquel XR
• Setinin
• Smoodipin
• Socalm
• Sondate XL
• Squro
• Tevaquel
• Tiamax
• Toliken
• Torquite SR
• Utapine
• Vesparax
• Victus
• Zaluron XL

Quetiapine Brand Names in Pakistan:

Quetiapine Tablets 25 Mg in Pakistan
Angepine	Angelini Pharmaceuticals (Pvt) Ltd
Dequit	Shaheen Agencies
Esertia	Fassgen Pharmaceuticals
Evokalm	Pharmevo (Pvt) Ltd.
Kalm	Pharmevo (Pvt) Ltd.
Pequit	Medizan Labs (Pvt) Ltd
Q-Par	Helix Pharma (Private) Limited
Qpin	Dyson Research Laboratories
Quepin	Platinum Pharmaceuticals (Pvt.) Ltd.
Quepin	Platinum Pharmaceuticals (Pvt.) Ltd.
Quepin	Platinum Pharmaceuticals (Pvt.) Ltd.
Quet	Adamjee Pharmaceuticals (Pvt) Ltd.
Quit	Navegal Laboratories
Quit	Navegal Laboratories
Quit	Navegal Laboratories
Quitin	Werrick Pharmaceuticals
Quopine	Medisure Laboratories Pakistan (Pvt.) Ltd.
Qupin	Cellgene Pharmaceuticals International
Qusal	Opal Laboratories (Pvt) Ltd.
Qusel	Hilton Pharma (Pvt) Limited
Qutapin	The Schazoo Laboratories Ltd.
Qutenza	Hiranis Pharmaceuticals Pvt Ltd
Qutirate	Shrooq Pharmaceuticals
Qutyl	Consolidated Chemical Laboratories (Pvt) Ltd.
Repose	Maark Pharma
Sero-Q	Global Pharmaceuticals
Seropine	Polyfine Chempharma (Pvt) Ltd.
Seroquel	Ici Pakistan Ltd.
Simbec	Don Valley Pharmaceuticals (Pvt) Ltd.
Tiapin	Adamjee Pharmaceuticals (Pvt) Ltd.
Togal	Akhai Pharmaceuticals.
Xaspine	Mass Pharma (Private) Limited

 

Quetiapine Tablets 100 Mg in Pakistan
Angepine	Angelini Pharmaceuticals (Pvt) Ltd
Dequit	Shaheen Agencies
Esertia	Fassgen Pharmaceuticals
Evokalm	Pharmevo (Pvt) Ltd.
Kalm	Pharmevo (Pvt) Ltd.
Pequit	Medizan Labs (Pvt) Ltd
Pine	Werrick Pharmaceuticals
Q-Par	Helix Pharma (Private) Limited
Quepin	Platinum Pharmaceuticals (Pvt.) Ltd.
Quepin	Platinum Pharmaceuticals (Pvt.) Ltd.
Quepin	Platinum Pharmaceuticals (Pvt.) Ltd.
Quet	Adamjee Pharmaceuticals (Pvt) Ltd.
Quet	Adamjee Pharmaceuticals (Pvt) Ltd.
Quet	Adamjee Pharmaceuticals (Pvt) Ltd.
Quetapine	Swan Pharmaceuticals(Pvt) Ltd
Quitin	Werrick Pharmaceuticals
Quitin-Flash	Werrick Pharmaceuticals
Quopine	Medisure Laboratories Pakistan (Pvt.) Ltd.
Qupin	Cellgene Pharmaceuticals International
Qusal	Opal Laboratories (Pvt) Ltd.
Qusel	Hilton Pharma (Pvt) Limited
Qutapin	The Schazoo Laboratories Ltd.
Qutec	Panacea Pharmaceuticals
Qutenza	Hiranis Pharmaceuticals Pvt Ltd
Qutirate	Shrooq Pharmaceuticals
Qutyl	Consolidated Chemical Laboratories (Pvt) Ltd.
Sero-Q	Global Pharmaceuticals
Seroquel	Ici Pakistan Ltd.
Simbec	Murfy Pharmaceuticals (Pvt) Ltd
Tiapin	Adamjee Pharmaceuticals (Pvt) Ltd.
Togal	Akhai Pharmaceuticals.
Xaspine	Mass Pharma (Private) Limited
Ziapine	Mass Pharma (Private) Limited

 

Quetiapine Tablets 150 Mg in Pakistan
Pequit Xr	Genetics Pharmaceuticals
Qusel	Hilton Pharma (Pvt) Limited

 

Quetiapine Tablets 200 Mg in Pakistan
Dequit	Shaheen Agencies
Evokalm	Pharmevo (Pvt) Ltd.
Q-Par	Helix Pharma (Private) Limited
Qepine	Crown Pharmaceuticals
Quit	Navegal Laboratories
Quopine	Medisure Laboratories Pakistan (Pvt.) Ltd.
Qusal	Opal Laboratories (Pvt) Ltd.
Qusel	Hilton Pharma (Pvt) Limited
Qusel Xr	Hilton Pharma (Pvt) Limited
Qutec	Panacea Pharmaceuticals
Qutenza	Hiranis Pharmaceuticals Pvt Ltd
Qutyl	Consolidated Chemical Laboratories (Pvt) Ltd.
Quziq	Wilshire Laboratories (Pvt) Ltd.
Serewel Sr	Ray Pharma (Pvt) Ltd
Serewel Sr	Ray Pharma (Pvt) Ltd
Sero-Q	Global Pharmaceuticals
Seropine	Polyfine Chempharma (Pvt) Ltd.

 

Quetiapine Tablets 300 Mg in Pakistan
Pequit Xr	Genetics Pharmaceuticals
Quopine	Medisure Laboratories Pakistan (Pvt.) Ltd.
Xaspine	Mass Pharma (Private) Limited

 

Quetiapine Tablets 400 Mg in Pakistan
Repose Xr	Maark Pharma
Serewel Sr	Ray Pharma (Pvt) Ltd