Quetiapine
An antipsychotic for schizophrenia and bipolar disorder. Low doses for sleep or anxiety are not approved and not recommended.
Brand names
- Seroquel, Seroquel XR (extended-release), plus generic brands
How it works
It blocks dopamine and serotonin receptors, steadying psychotic symptoms and mood. Blocking histamine and alpha receptors causes drowsiness and dizziness on standing.
Used for
- Schizophrenia (TGA-approved)
- Bipolar disorder: mania, depression and preventing relapse (TGA-approved)
- Major depression, added to an antidepressant (Seroquel XR, TGA-approved)
- Low doses for sleep or anxiety are off-label and not recommended. The risks (weight gain, diabetes, high cholesterol, heart rhythm changes) outweigh the benefits
Side effects
How often, from the official product information. Bold = serious.
Very common more than 1 in 10
- Drowsiness, dizziness, headache
- Dry mouth, lower haemoglobin
- Weight gain
- Raised cholesterol, triglycerides
- Stiffness, tremor, restlessness
- Withdrawal if stopped suddenly
Common 1 in 10 to 1 in 100
- Low white cells, thyroid changes
- High blood sugar, more appetite
- Raised prolactin, liver enzymes
- Odd dreams, suicidal thoughts
- Fast heartbeat, breathlessness
- Dizzy on standing, blurred vision
- Constipation, indigestion, vomiting
- Weakness, swollen ankles, fever
Uncommon 1 in 100 to 1 in 1,000
- Low neutrophils or platelets
- Diabetes, low sodium
- Allergy, underactive thyroid
- Seizures, fainting, confusion
- Tardive dyskinesia (lasting tics)
- Long QT, slow heart rate
- Swallowing, urine or sexual problems
Rare 1 in 1,000 to 1 in 10,000
- Agranulocytosis (no white cells)
- Neuroleptic malignant syndrome
- Pancreatitis, bowel blockage
- Jaundice, hepatitis, blood clots
- Metabolic syndrome, sleepwalking
- Prolonged erection, period changes
Very rare fewer than 1 in 10,000
- Anaphylaxis or angioedema
- Stevens-Johnson syndrome
- Muscle breakdown
Frequency not known reported, rate unclear
- Heart muscle inflammation
- Severe skin reactions
- Stroke
- Withdrawal in newborns
Get help urgently if
- High fever, stiff muscles, confusion and sweating (possible neuroleptic malignant syndrome)
- Fever, sore throat or mouth ulcers (possible low white cells)
- Chest pain, fainting or a racing, irregular heartbeat
- Very thirsty and passing lots of urine (high blood sugar)
- Thoughts of suicide or self-harm: Lifeline 13 11 14, or 000
Good to know
- Metabolic monitoring: weight, waist, blood pressure, blood sugar and cholesterol are checked before starting and regularly after.
- Not approved for dementia: higher risk of stroke and death in older people with dementia.
- Avoid alcohol. Don’t drive until you know how it affects you. Avoid grapefruit juice; some antibiotics and antifungals raise levels.
- Stopping: reduce slowly to avoid nausea, vomiting, poor sleep and relapse.
- Pregnancy or breastfeeding: discuss with your doctor before starting or stopping.
Information only. Not a recommendation or endorsement of any product. Whether a medicine suits you depends on your health and other medicines, so talk to your doctor or pharmacist. In an emergency, call 000.
More information
maladywise.com/drugs/quetiapine/