Quetiapine is used to treat and relieve symptoms common in schizophrenia (long-term mental disorder that causes changes in thoughts, feelings, and behaviour) and bipolar disorder (mood changes between feeling very high (mania) and very low (depression) such as distorted thinking and emotional instability.
Quetiapine is also used together with other medicines to treat depression.
Take Quetiapine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
Quetiapine may be available as conventional tablets and as extended-release tablets.
If you have been given the conventional tablet, you may take it with or without food.
If you are taking extended-release tablet (usually marked as "XL" or "XR"), take it on an empty stomach without food or with a light meal (<300 calories). Do not cut, chew or crush this tablet. Swallow it whole with a glass of water.
Take this medicine at about the same time each day.
Quetiapine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed otherwise, as stopping it suddenly could worsen your condition.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Quetiapine is not suitable for elderly patients with dementia-related psychosis.
Do not take Quetiapine with medicines used to treat infections, HIV infections, fungal infections, or depression. Please see the section “Can I take this with other medicines?” below for more information.
Inform your doctor if you have the following conditions:
- heart disease
- kidney disease
- liver disease
- low blood pressure
- Parkinson's disease (a disorder that affects the movement of a person, causing symptoms such as tremors, muscle stiffness, slowed movement and impaired balance or walking)
- epilepsy (fits or seizures)
- high levels of cholesterol in the blood
- brain damage
- history of alcohol or drug abuse
- suicidal thoughts
- urinary retention (inability to completely empty the bladder when urinating)
- benign prostatic hypertrophy (prostate enlargement)
- increased pressure inside your eye
- Alzheimer’s disease (a progressive disease which destroys memory and other important mental functions)
Let your doctor know if you are pregnant or breastfeeding.
Quetiapine may affect your blood sugar levels. You may need to monitor your blood sugar levels more regularly while being treated with Quetiapine.
Quetiapine may affect the way your body adjusts to temperature changes in the environment. Avoid exposure to very cold or very hot environments. Avoid strenuous exercise or activities such as going to the sauna. Drink plenty of water to prevent dehydration.
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
Routine tests (e.g. liver function, electrolyte levels, CBC, blood glucose, eye examination, thyroid assessment) may be done while you are being treated with this medicine.
Your doctor will advise you about how often you need to have these tests.
Medicines for depression such as Quetiapine may increase the risk of suicidal thoughts and behaviour. As depression and some psychiatric disorders are themselves associated with an increased risk of suicide, it is important for you or your family members to monitor your condition especially at the start of treatment and if your dosage is still being adjusted. If you experience new or sudden changes in mood, behaviour, thoughts or feelings or a worsening of your depression with suicidal thoughts or attempts, harm to self or harm to others, contact your doctor immediately.
Quetiapine may cause drowsiness, dizziness and tiredness. It may also cause you to suddenly fall asleep during your daily activities such as eating and watching television. You may not feel drowsy before you fall asleep. If affected, do not drive or take part in any activity in which you need to be alert.
This medicine may cause your blood pressure to fall suddenly when you get up from a sitting or lying down position and you may feel giddy. To minimise this problem, stand up slowly. This is normal and should disappear gradually as you get used to the medicine.
Other side effects include the following: increased appetite, weight gain, headache, dry mouth, agitation, blurred vision, stomach discomfort, indigestion, constipation, nausea, vomiting, difficulty urinating, tiredness, abnormal dreams or nightmares, and depression.
Some side effects may need immediate medical help. Alert your doctor immediately if you experience any of the following:
- confusion and hallucinations (seeing, hearing or feeling things that are not existent)
- unusual changes in mood or behaviour (being aggressive, agitated, or having compulsive and impulsive behaviour)
- having thoughts of self-harm
- fast or irregular heartbeat
- chest pain
- muscle stiffness, unexplained high fever
- uncontrolled twitching movements of the mouth, tongue and limbs, such as sticking out of the tongue, smacking of the lips
- fever, flu-like symptoms, sore throat or any other infection
- constipation along with stomach pain
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Do not take Quetiapine if you are taking any of these medicines:
- medicines for HIV infection e.g. ritonavir, saquinavir, indinavir
- medicines to treat fungal infection e.g. ketoconazole, itraconazole, fluconazole
- certain antibiotics e.g. erythromycin, clarithromycin
- medicine to treat depression e.g. nefazodone
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicines for sleep disorders and anxiety medicines e.g. lorazepam
- other psychiatric medicines e.g. thioridazine
- medicines for epilepsy e.g. phenytoin, carbamazepine
- medicines to treat TB (lung infection known as tuberculosis) e.g. rifampicin
- medicines for Parkinson's disease e.g. levodopa
- herbal medicine e.g. St. John’s wort
This list does not include all medicines that may interact with Quetiapine.
Always notify your doctor or pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.