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Quetiapine (Seroquel®, Seroquel XR®)

Quetiapine (Seroquel®, Seroquel XR® and generic forms) belongs to a group of medications called “atypical antipsychotics” or “second-generation antipsychotics”.

What is this medication used for?

Quetiapine was first developed to treat psychotic illnesses such as schizophrenia. Quetiapine is not approved by Health Canada for use in children and adolescents.

When potential benefits outweigh risks, quetiapine may be prescribed “off-label” for treatment of schizophrenia and other psychotic disorders, bipolar disorder, irritability associated with autism, depression or anxiety disorders, and management of aggressive behaviour. Learn more about off-label medication use:

Tell your doctor or pharmacist if you:

  • Have allergies or bad reactions to a medication
  • Take (or plan to take) other prescription or non- prescription medications, including natural medicines Some medications interact with quetiapine. Your doctor may adjust medication doses or monitor for side effects
  • Have a history of heart, kidney or liver disease, seizures, bowel obstruction, trouble urinating, low white blood cell count, glaucoma or sleep apnea
  • Have a history (or family history) of diabetes, heart disease, arrhythmia or “familial long QT syndrome”
  • Miss a menstrual period, are pregnant, breast-feeding or planning a pregnancy
  • Use alcohol or drugs. Taking quetiapine together with certain substances may cause a bad reaction. Learn more at

When will the medication start to work?

Quetiapine is usually prescribed to be taken regularly, but it is sometimes taken on an ‘as needed’ basis.

Some improvements may be seen within 1 to 2 weeks. It can take up to 6 weeks to see the full benefits of the medication. You (or your family members) may notice clearer thoughts, less moodiness, anger, irritability, or explosive behaviour. If you experience seeing, hearing or feeling things that are not there, this may also decrease or stop entirely.

It is important that you continue taking quetiapine regularly even if you are feeling well, as it can prevent symptoms from returning. Talk with your doctor if you feel quetiapine treatment has not been helpful or

if side effects are too bothersome. Your doctor may recommend switching you to a different medication.

This medication is not addictive. Do not stop taking it before talking to your doctor.

How do I take this medication?

Quetiapine is available as tablets and extended-release (XR) tablets. Some people may only need to take quetiapine occasionally or on an as-needed basis, while othersmay take it regularly. If you take it regularly, quetiapine is usually taken once daily in the evening (XR tablets) or twice a day in the morning and evening (regular tablets) , at the same time(s) each day.

You may take quetiapine with or without food. Usually, you will start with a low dose and slowly increase this dose over several days or weeks, based on how you tolerate it. Quetiapine XR tablets should be swallowed whole with fluids. Do not crush, chew or divide quetiapine XR tablets.

Possible common or serious side effects:

Side effects may be more common when starting a medication or after a dose increase. Talk to your doctor, nurse or pharmacist if any side effect concerns you.

  • Dizziness, drowsiness, headache or dry mouth
  • Feelings of agitation or restlessness
  • Stomach ache or constipation
  • Fast or irregular heartbeat
  • Increased appetite or weight gain
  • Increased blood glucose or cholesterol levels

Contact your doctor immediately if you experience:

  • Unexplained rash, seizure, fever or excessive sweating
  • Fainting, feeling lightheaded or difficulty with balance
  • Feelings of restlessness or severe abdominal pain
  • Excessive snoring or periods of not breathing during sleep (sleep apnea)
  • Signs of infection (fever, sore throat, flu-like symptoms)
  • Breast tenderness or swelling (males and females)
  • Frequent urination accompanied by excessive thirst
  • Shaking, muscle spasm/stiffness, pain or weakness
  • Unusual movements of fingers, toes, neck, lips or tongue
  • Thoughts of hurting yourself, suicide, increased hostility or worsening symptoms

What precautions should my doctor and I be aware of when taking this medication?

  • When you take this medication, your body may have difficulty maintaining a normal body temperature. Drink enough fluids to avoid becoming dehydrated. Avoid doing a lot of physical activity on hot days.
  • While taking this medication, if you feel dizzy, drowsy or slowed down, do not drive a car or operate heavy machinery. Alcohol could make this worse. Try to avoid alcohol while taking quetiapine.
  • Quetiapine can cause a rare side effect called “tardive dyskinesia.” Symptoms include involuntary movements of the lips, tongue, toes, hands or neck. Stopping or switching this medication at first signs will decrease the chances this side effect will continue. These movements may become permanent without a medication change.
  • Quetiapine can cause a rare side effect called “neuroleptic malignant syndrome.” Symptoms include severe muscle stiffness, high fever, sweating, increased or irregular heartbeat and increased blood pressure.

How do I store this medication?

Keep this medication in the original container, stored at room temperature away from moisture and heat and protected from light. Keep this medication out of reach and sight of children.

What special instructions should I follow while using this medication?

  • Keep all appointments with your doctor and the lab. Your doctor may order lab tests to check how you are responding and monitor for side effects.
  • Try to keep a healthy, well-balanced diet and exercise regularly. Some people may gain weight as a result of increased appetite.
  • Do not allow anyone else to use your medication.

What should I do if I forget to take a dose of this medication?

If you take quetiapine tablets regularly and forget to take a dose, take the missed dose as soon as you remember. However, if it is within 4 hours of your next scheduled dose, skip the missed dose and continue with your regular schedule.

If you take quetiapine XR once daily in the evening and forget to take a dose, take it as soon as you remember before going to sleep. If you remember after waking in the morning, skip the missed dose and continue regularly with your next scheduled dose. DO NOT double your next dose to try to ‘catch up’.

How does this medication work?

Like other atypical antipsychotics, quetiapine affects actions of the brain chemicals dopamine and serotonin. The exact way that quetiapine improves symptoms of schizophrenia, bipolar disorder, depression, anxiety and other conditions is not known.

How well does the medication work in children and adolescents?

Evidence supports the use of quetiapine in children and adolescents. Quetiapine has been shown to be better than placebo (an inactive pill) for treatment of schizophrenia, manic episodes associated with bipolar disorder and conduct disorder (aggression.) Quetiapine has been studied in children and adolescents with depressive episodes of bipolar disorder as well as in adults with social anxiety disorder, and has been shown to be no better than placebo in both cases. Quetiapine has not been studied in children and adolescents for treatment of irritability associated with autism. It is sometimes prescribed for treatment of irritability of autism when patients have experienced adverse effects with other antipsychotics.

How long should I take the medication for?

This depends on the symptoms you have, how frequently they occur, and how long you have had them. Most people will need to take quetiapine for several months. This allows time for symptoms to stabilize and for function to improve. Your doctor will discuss the benefits and risks of taking quetiapine with you. At this time, you can also discuss how long you might need to take this medication.

If you have schizophrenia and you tolerate quetiapine well, you may be asked to take quetiapine on an ongoing basis. Continuing treatment will significantly decrease the chance that your symptoms will return.

Do not increase, decrease, or stop taking this medication without talking with your doctor. If you stop taking quetiapine suddenly, it is possible that your symptoms may return or you may have a bad reaction.

TIP: Use the Kelty Mental Health Antipsychotic Monitoring Form for Children and Adolescents to help measure your progress on this medication.

Also see the Kelty Mental Health document Atypical Antipsychotics & Metabolic Monitoring.

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