What is this medication for?

Quetiapine belongs to a class of medications known as atypical (second-generation) antipsychotics. It is used to treat and prevent the return of symptoms in Schizophrenia and other mental health related conditions such as:

• Hearing, seeing or sensing things that are not real

• Having mistaken beliefs

• Being overly suspicious

• Uncontrolled anger

It can also be used to treat symptoms in bipolar disorder such as:

• Overly excited mood

• Feeling irritable

• Increased activity and energy

• Low mood

Quetiapine may be used for other conditions. Check with your healthcare professional if you are unsure why you are given this medication.

How should I take/use this medication?

• Follow the directions on your medication label and take the medication as prescribed by your doctor. Quetiapine may be taken with or without food.

• If you are taking Quetiapine XR (extended-release) tablet, swallow the tablet whole - Do not split, crush or chew.

• Quetiapine needs to be taken regularly for a few weeks before you feel its full benefits. You should not stop taking this medicine even if you do not feel better at the beginning. Continue to take this medicine even after you feel better to prevent your symptoms from returning.

• Do check with your doctor on how long you will have to be on this medication.

• Do not stop taking your medication without checking with your healthcare professional.

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose. Then take the next dose at your usual timing. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

• You are allergic to this medication or any of the other ingredients of this medication

• You are pregnant, planning to become pregnant, or breastfeeding. If you are pregnant and/or breastfeeding, your doctor would have discussed the potential benefits and side-effects with you and should you have further questions or concerns, do consult your doctor.

• You are taking any other medications including over the counter medications, supplements, traditional Chinese medicine and herbal remedies. Some of them may affect how this medication works or cause serious drug interactions.

• You have diabetes. Quetiapine may sometimes worsen blood sugar control in diabetes. Maintain regular check-ups with your doctor.
  

• You have or have ever had:
  

• Drug allergies
  
• Medical conditions such as:
• Blood disorders, irregular heartbeat or heart problems; kidney, liver or thyroid disease, breast cancer, stroke
• High or low blood pressure, high cholesterol / fats in the blood, seizures (fits), Alzheimer’s disease (a type of dementia)
  

IMPORTANT

In some cases, particularly in young people below the age of 25 years, this medication may cause the following changes to a person’s mental condition, especially in the first few weeks of treatment or during dose changes:

• New or worsening thoughts of harming yourself or ending your life

• Worsening agitation, restlessness, violent behaviour, or

• Other changes in mood or behaviour

Please inform your doctor as soon as possible, or for your family or caregiver to inform your doctor if you are unable to seek treatment on your own.

Do not stop taking this medication on your own without discussing with your doctor.

It is important to note that your doctor has prescribed this medication as he/ she feels you will benefit more from taking this medication over the possible risks that it may cause, which have a low chance of occurring, and most people take this medication without any of such problems.

What are some common side-effects of this medication?

The mentioned side effects generally affect up to 10% of patients.

• Feeling tired or drowsy
• Discuss with your doctor if you can take this medication at a different time of the day.
• Avoid driving, or engaging in activities requiring concentration

• Nausea or vomiting
• Take the medication with or after food
• Take small but frequent meals and avoid fatty or spicy food

• Constipation
• Drink more water (if not on fluid-restricted diet), eat more high-fiber foods, and exercise regularly
• Speak to your doctor or pharmacist if you need a medication to help with your constipation

• Light-headedness (especially during sudden change in posture)
• Get up slowly from sitting or lying down position

• Dry mouth
• Chew sugar-free gum, suck on sugar-free hard candies or ice chips, sip water regularly

• Increase in appetite, weight gain
• Observe healthy dietary habits and exercise regularly

• Involuntary shaking of limbs (tremors)
• Speak to the doctor if this affect your daily life

Most of the side effects listed here will improve with time. Speak to your healthcare professional if they continue, get worse or are affecting your daily life.

What are some rare but serious side-effects that I need to seek medical advice immediately?

The symptoms of a drug allergy include one or more of the following:

• Swollen face/eyes/lips/tongue

• Difficulty in breathing

• Itchy skin rashes over your whole body

Rarely this medication may cause:

• Seizures (fits)

• Confusion, high fever, severe muscle stiffness, irregular blood pressure (signs and symptoms of neuroleptic malignant syndrome)

• Muscle movement side effect (extrapyramidal side effects):

  • Muscle stiffness and spasms (such as in the face, neck and back), difficulty in speaking or swallowing, twitching, or upward rolling of eyes (symptoms of dystonia)

  • Restlessness or need to keep moving constantly (akathisia)

  • Uncontrollable movements (such as in the face, tongue, jaw or other parts of the body) (tardive dyskinesia)

• Blurred vision

• Fainting episodes (syncope)

• Difficulty in passing urine (urinary retention)

• Fast or irregular heartbeat, fainting episodes (abnormal heart beating rhythm (prolonged QTc interval))

• Fever, sore throat and/or mouth ulcers that do not go away (symptoms of blood dyscrasias)

• Severe chest pain, difficulty breathing, or severe pain or swelling in either of the legs (symptoms of venous thromboembolism)

• Excessive hunger, unusual increase in thirst or passing large amount of urine (symptoms of high blood sugar)

• Increased prolactin hormone in the body (hyperprolactinemia):

  • Changes in menstrual cycle in females (Irregular or stopping of menstrual periods) and/or

  • Abnormal breast swelling, soreness or secretion (in both men and women)
    

• Sudden weakness or numbness in the face, arms or legs, and speech or vision problems

If you experience any of these side effects, you should stop your medication and inform your healthcare professional immediately.

Please also take note that the above listed side effects are not exhaustive. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

What food or medication should I avoid when I take this medication?

Avoid drinking alcohol while taking Quetiapine as it can cause excessive drowsiness.

Avoid taking grapefruit when you are taking this medicine as grapefruit may interact with your medicine and increase the risk of side-effects.

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.

Disclaimers

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on Jun 2021