Quetiapine (Seroquel)

Naomi Carr
Author: Naomi Carr Medical Reviewer: Dr. Brittany Ferri, PhD Last updated:

Quetiapine, commonly known as Seroquel, is an atypical antipsychotic medication, used in the treatment of several mental health conditions, such as schizophrenia and bipolar disorder. It is important to take this medication exactly as prescribed and consult with your doctor before starting any other medication (prescribed or over the counter) while on quetiapine, as adverse effects can occur.

Quetiapine brand names

  • Seroquel

What is quetiapine prescribed for?

Quetiapine is a second-generation antipsychotic drug. It is approved by the US Food and Drug Administration (FDA) for the treatment of several mental health conditions [1]:

Medications are also used for treatments that are not FDA approved, known as off-label treatment. Quetiapine is used as off-label treatment for [2]:

It is also used as off-label treatment in addition to an antidepressant for:

Quetiapine is not FDA approved to treat people under 10 years old, as the effectiveness and safety of the medication in this age group has not been established.

How does quetiapine work?

Quetiapine is a second-generation, or atypical, antipsychotic medication. This group of medications all work in the same way, by regulating the levels of the neurotransmitters called dopamine and serotonin [2].

Quetiapine reduces the concentration of these neurotransmitters, which helps to improve mood and behavior and reduce symptoms of psychosis, making it a useful medication for a variety of conditions [1].

How is quetiapine usually taken?

Quetiapine is available as an immediate-release tablet and an extended-release tablet, in varying strengths from 25mg up to 400mg.

Immediate-release tablets are taken 2-3 times per day, as they release the medication into the body quickly, whereas extended-release tablets are taken only once per day, as the medication is released into the body slowly throughout the day. Extended-release tablets should be taken without food and should be swallowed whole without crushing or breaking [3].

When you begin treatment, your doctor will likely prescribe low doses of quetiapine and slowly increase the dosage, to prevent serious side effects from occurring and slowly bring the medication levels to the most effective therapeutic dose.

For older adults requiring quetiapine treatment, doses will begin much lower and will be increased more slowly, as there are higher risks of side effects in this age group [4].

For the treatment of schizophrenia:

  • Immediate-release tablets: your dose will likely start at 50mg per day, split into two doses, and will be gradually increased up to a therapeutic dose of between 300-800mg, split into 2 or 3 doses.
  • Extended-release tablets: your dose will likely start at 300mg per day, which will gradually be increased up to 800mg, to be taken in one dose at bedtime.

For the treatment of manic episodes or maintenance of bipolar depression:

  • Immediate-release tablets: your dose will likely start at 100mg per day, split into two doses, which will gradually be increased up to 800mg per day, split into 2-3 doses
  • Extended-release tablets: your dose will likely start at 300mg per day and will be increased up to 800mg per day, to be taken in one dose at bedtime.

For the adjunct treatment of major depressive disorder, to be taken along with an antidepressant:

  • Immediate-release tablets: you will be prescribed a dose that can be increased up to between 50-300mg per day, to be split into 2-3 doses.
  • Extended-release tablets: you will be prescribed a dose that can be increased up to between 150-300mg per day, to be taken in one dose.

Quetiapine is approved for daily doses of up to 800mg and it is typically effective for most people when prescribed between 300-800mg per day. However, occasionally higher doses are required for effective treatment, of up to 1600mg per day, which requires more regular monitoring of physical symptoms, as the risk of side effects is increased at this dosage [2].

Your doctor will monitor your mental and physical health throughout your treatment and may change your dose depending on your response to the medication, any side effects that you experience, and changes in your symptoms.

This medication should be taken as prescribed, without missing a dose. If a dose is missed, take the medication as soon as possible, or if it is close to the next dosage time, skip the missed dose. Never take double your prescribed dose in one go, as this can have adverse effects and may increase the risk of side effects.

How long does quetiapine stay in your system?

When you start taking quetiapine, you may notice changes in your symptoms within the first few weeks, but it can take 2-3 months before you feel the full effect of the medication [1]. As such, it is important that you continue to take your medication consistently, to ensure you reach the most effective therapeutic dose.

If you stop taking quetiapine, the effects of the medication will likely wear off within a few days, but it may take several weeks before it has entirely left your system.

Do not suddenly stop taking quetiapine, even if you feel better, as this can have serious impacts on your physical and mental health and can worsen your condition. If your doctor advises that it is safe to come off this medication, they will likely reduce your prescription slowly, to prevent adverse effects and withdrawal symptoms.

Quetiapine side effects

When you begin a new medication, you may experience some common side effects. They will likely reduce within the first week or two, but if they continue or become problematic, consult your doctor immediately, as you may need a reduced dose or a change of medication.

Common side effects of quetiapine include:

  • Feeling drowsy and tired
  • Headache
  • Joint pain
  • Difficulty concentrating
  • Agitation
  • Feeling dizzy and unsteady
  • Increase in appetite and weight
  • Dry mouth
  • Constipation
  • Vomiting
  • Unusual dreams
  • Increase in blood pressure
  • Increase in heartrate
  • Unusual movements
  • Increased prolactin, which can cause milk production and stopped periods in females, and sexual dysfunction in males

Serious side effects of quetiapine are less common but may still occur. Call your doctor immediately if you experience any of the following:

  • Tremor and shaking
  • Extreme thirst
  • Pain or stiffness in the muscles
  • Uncontrollable movements in the mouth or body
  • Changes in vision
  • Confusion
  • Fever
  • Irregular heartbeat
  • Unexplained bleeding or bruising
  • Rash or hives
  • Fainting
  • Difficulty breathing
  • Malignant syndrome

Quetiapine precautions

Quetiapine can cause suicidal thoughts, particularly at the beginning of your treatment. This risk has been found to be higher in people under the age of 24 years old [4]. If you or your family notice any concerning changes in your mental state, or you experience thoughts of harming yourself, contact a medical professional immediately.

It is important that your doctor is aware of any past or present mental health conditions you have experienced, to enable safe monitoring of your condition while on this medication, or to decide if it is safe for you.

Discuss with your doctor all your past and present physical health conditions, as they may impact your ability to take this medication safely.

Tell your doctor if you have experienced any heart, liver, kidney, or thyroid conditions, diabetes, seizures, low potassium or magnesium levels, or cataracts, as it may not be safe for you to take this medication, or your doctor may wish to prescribe a lower dose and carefully monitor your physical health during your treatment [3].

People over the age of 65 may be at increased risk of serious side effects or stroke, so it is advisable for people in this age group to use lower doses or alternative medications where possible [4]. Antipsychotic medications should not be used to treat psychosis in the context of dementia [1].

Quetiapine can cause an impaired ability to regulate body temperature, so it is advised to be careful when in the sun or when doing exercise, as it may take longer for the body to return to a normal temperature.

Quetiapine can cause an increase in weight, blood sugar, and cholesterol, so you may require regular tests to check your glucose and cholesterol levels. You may wish to talk to your doctor about how to maintain a healthy weight during your treatment, including healthy eating and exercise, to prevent unwanted weight gain [1].

Depending on your prescription and the length of time you have been on this treatment, you may experience withdrawal symptoms when coming off this medication [4]. Your doctor will likely reduce your prescription slowly to prevent this. Taking quetiapine exactly as prescribed by your doctor can also help to prevent withdrawal symptoms.

Ensure you tell your doctor if you are pregnant or planning to become pregnant while taking quetiapine, as it may cause harm to the fetus and withdrawal symptoms in newborns. Untreated schizophrenia can cause harm to both mother and baby, so it is advised to discuss the available options with your doctor, to ensure you receive appropriate treatment for your condition, while managing the risks to your baby [1].

Tell your doctor if you are breastfeeding, as quetiapine can be passed to your baby in breast milk, so should be used with caution if required, with careful monitoring of your baby, or alternative options can be considered [4].

This medication can cause drowsiness and sedation, so it is important to avoid driving until you are aware of how quetiapine affects you and it is safe to do so.

Tell your doctor about all medications you are currently taking, or plan to take (including vitamins and dietary supplements), as they may cause adverse reactions.

Quetiapine interactions

Some medications may interact with quetiapine, causing a decrease in the effectiveness of your medication, or an increase in the risk of side effects. This includes heart medications, antivirals, antihistamines, antifungals, barbiturates, steroids, other antipsychotics, medications for anxiety, sedatives, tranquilizers, and sleeping pills [3].

Always discuss your medications with your doctor before starting a new treatment.

It is advised to avoid or limit alcohol intake while on quetiapine, as alcohol can decrease the effectiveness of your medication and cause an increase in side effects [1].

It is advised not to eat or drink grapefruit while on quetiapine, as grapefruit juice can affect the levels of medication in your body [3].

Quetiapine storage

Always keep all medications out of reach of children.

Store quetiapine in its original packaging, in airtight containers, and at room temperature (68°F to 77°F).

If you need to dispose of medication that is out of date or no longer needed, contact a medical professional to ensure it is disposed of appropriately. Never flush medications down the toilet or put them in the bin, as this can create unnecessary risks.

What to do if you overdose on quetiapine

If you overdose on quetiapine, call a medical professional, or Poison Control on 1-800-222-1222, or in case of an emergency, call 911. Symptoms of a quetiapine overdose include drowsiness, dizziness, irregular or fast heartbeat, fainting, seizures, or coma [5].

Frequently asked questions about quetiapine

Is quetiapine a sleeping pill?

Quetiapine can be prescribed for off-label uses, one of which is for the treatment of insomnia disorder in adults. It has sedating effects, so can be useful in improving sleep and getting to sleep.

However, the reason it is not FDA approved for this use is the increased risk of side effects when compared to other sleep treatments. As such, it is advised to consider alternative medications for insomnia or other sleep disorders, as there are several medications available that cause fewer adverse effects [6].

What does quetiapine do to your mood?

Quetiapine works by altering the levels of dopamine and serotonin in the brain, which are responsible for emotion regulation. As such, it can improve and stabilize mood, reducing symptoms of depression and negative symptoms of schizophrenia, as well as helping to manage symptoms of mania and psychosis [2].

How long can you stay on quetiapine?

It is safe to take quetiapine long-term, with careful monitoring of physical changes. Long-term use of antipsychotic drugs can cause an increase in movement-related side effects, known as tardive dyskinesia, which may include uncontrollable movements in the mouth [1].

Ensure you tell your doctor about any side effects, so they can ensure you remain safe and monitor any concerning symptoms, making changes to your medication if required.

Long-term use of antipsychotic drugs can also increase the risk of weight gain and diabetes, so it is advised to consult with your doctor about the ways you can prevent weight gain and maintain a healthy lifestyle. Your doctor will likely monitor your blood sugar and cholesterol, to ensure they remain at healthy levels [1].

  1. The College of Psychiatric and Neurologic Pharmacists (CPNP) and the National Alliance on Mental Illness (NAMI). (Updated 2016). Quetiapine (Seroquel). NAMI. Retrieved from https://www.nami.org/About-Mental-Illness/Treatments/Mental-Health-Medications/Types-of-Medication/Quetiapine-(Seroquel)
  2. Maan, J.S., Ershadi, M., Khan, I., & Saadabadi, A. (2022). Quetiapine. In StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK459145/
  3. American Society of Health-System Pharmacists, Inc. (Revised 2020). Quetiapine. MedlinePlus. Retrieved from https://medlineplus.gov/druginfo/meds/a698019.html
  4. AstraZeneca Pharmaceuticals LP. (Revised 2013). Seroquel. Access Data FDA. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/020639s061lbl.pdf
  5. Hustey, F.M. (1999). Acute Quetiapine Poisoning. The Journal of Emergency Medicine, 17(6), 995–997. Retrieved from https://doi.org/10.1016/s0736-4679(99)00128-6
  6. Coe, H. V., & Hong, I. S. (2012). Safety of Low Doses of Quetiapine When Used for Insomnia. The Annals of Pharmacotherapy, 46(5), 718–722. Retrieved from https://doi.org/10.1345/aph.1Q697


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Naomi Carr
Author Naomi Carr Writer

Naomi Carr is a writer with a background in English Literature from Oxford Brookes University.

Published: Dec 22nd 2022, Last edited: Sep 22nd 2023

Brittany Ferri
Medical Reviewer Dr. Brittany Ferri, PhD OTR/L

Dr. Brittany Ferri, PhD, is a medical reviewer and subject matter expert in behavioral health, pediatrics, and telehealth.

Content reviewed by a medical professional. Last reviewed: Dec 21st 2022