From the Guidelines
Quetiapine can cause several side effects, including drowsiness, dizziness, dry mouth, constipation, increased appetite, weight gain, and fatigue, as well as more serious side effects like abnormal movements, high blood sugar, and QT prolongation, as noted in studies such as 1 and 1.
Common Side Effects
- Drowsiness
- Dizziness
- Dry mouth
- Constipation
- Increased appetite
- Weight gain
- Fatigue These side effects typically occur during the first few weeks of treatment and may diminish over time.
Serious Side Effects
- Abnormal movements (tardive dyskinesia)
- High blood sugar
- High cholesterol
- Low white blood cell count
- Neuroleptic malignant syndrome (characterized by fever, muscle rigidity, and altered mental status)
- QT prolongation, which may lead to irregular heartbeat in susceptible individuals Elderly patients with dementia-related psychosis have an increased risk of death when taking antipsychotics like quetiapine, as mentioned in 1.
Mechanism and Management
The medication works by blocking multiple neurotransmitter receptors, including dopamine and serotonin receptors, which explains both its therapeutic effects and side effect profile. Starting at a low dose and gradually increasing can help minimize side effects. Patients should not stop taking quetiapine abruptly as this can cause withdrawal symptoms, and should always consult their healthcare provider about any concerning side effects, as suggested by 1 and 1.
Special Considerations
It is essential to monitor patients for potential side effects, especially those with a history of medical conditions or taking other medications that may interact with quetiapine. Regular check-ups with a healthcare provider can help identify any issues early on and adjust the treatment plan as needed, as recommended in 1.
From the FDA Drug Label
High blood sugar could lead to: o build up of acid in your blood due to ketones (ketoacidosis) o coma o death Increases in blood sugar can happen in some people who take quetiapine fumarate tablets. Extremely high blood sugar can lead to coma or death If you have diabetes or risk factors for diabetes (such as being overweight or a family history of diabetes) your healthcare provider should check your blood sugar before you start quetiapine fumarate tablets and during therapy Call your healthcare provider if you have any of these symptoms of high blood sugar (hyperglycemia) while taking quetiapine fumarate tablets: o feel very thirsty o need to urinate more than usual o feel very hungry o feel weak or tired o feel sick to your stomach o feel confused, or your breath smells fruity • high fat levels in your blood (increased cholesterol and triglycerides) High fat levels may happen in people treated with quetiapine fumarate tablets. You may not have any symptoms, so your healthcare provider may decide to check your cholesterol and triglycerides during your treatment with quetiapine fumarate tablets. • increase in weight (weight gain) Weight gain is common in people who take quetiapine fumarate tablets so you and your healthcare provider should check your weight regularly. Talk to your healthcare provider about ways to control weight gain, such as eating a healthy, balanced diet, and exercising. • movements you cannot control in your face, tongue, or other body parts (tardive dyskinesia) These may be signs of a serious condition. Tardive dyskinesia may not go away, even if you stop taking quetiapine fumarate tablets. Tardive dyskinesia may also start after you stop taking quetiapine fumarate tablets • decreased blood pressure (orthostatic hypotension), including lightheadedness or fainting caused by a sudden change in heart rate and blood pressure when rising too quickly from a sitting or lying position. • increases in blood pressure in children and teenagers Your healthcare provider should check blood pressure in children and adolescents before starting quetiapine fumarate tablets and during therapy. • low white blood cell count • cataracts • seizures • abnormal thyroid tests: Your healthcare provider may do blood tests to check your thyroid hormone level • increases in prolactin levels: Your healthcare provider may do blood tests to check your prolactin levels. • sleepiness, drowsiness, feeling tired, difficulty thinking and doing normal activities • increased body temperature • difficulty swallowing • trouble sleeping or trouble staying asleep (insomnia), nausea, or vomiting if you suddenly stop taking quetiapine fumarate tablets These symptoms usually get better 1 week after you start having them The most common side effects of quetiapine fumarate tablets include: In Adults • dry mouth • constipation • dizziness • sore throat • weakness • difficulty moving • abdominal pain In Children and Adolescents: • nausea • increased appetite • dry mouth • vomiting • weight gain • rapid heart beat
The common side effects of quetiapine include:
- high blood sugar
- high fat levels in the blood
- weight gain
- tardive dyskinesia
- decreased blood pressure
- increases in blood pressure in children and teenagers
- low white blood cell count
- cataracts
- seizures
- abnormal thyroid tests
- increases in prolactin levels
- sleepiness
- drowsiness
- feeling tired
- difficulty thinking and doing normal activities
- increased body temperature
- difficulty swallowing
- trouble sleeping or trouble staying asleep (insomnia)
- nausea
- vomiting
- dry mouth
- constipation
- dizziness
- sore throat
- weakness
- difficulty moving
- abdominal pain
- nausea
- increased appetite
- vomiting
- rapid heart beat 2
From the Research
Quetiapine Side Effects
- Weight gain and increased levels of triglycerides, total cholesterol, and low-density lipoprotein (LDL) cholesterol, which are risk factors for cardiovascular morbidity and mortality 3
- Increased risk of major adverse cardiovascular events, especially in women and the elderly 3
- Metabolic effects, such as weight gain 4
- Neurological and cardiovascular symptoms, including drowsiness, coma, tachycardia, and hypotension 5
- Extrapyramidal side effects, sedation, somnolence, dizziness, fatigue, constipation, dry mouth, increased appetite, and weight gain 6
- Lower risk of headache in quetiapine-treated patients with acute bipolar depression 6
Risk Factors for Severe Side Effects
- Evaluated ingested dose of 1500 mg or greater 5
- Concomitant ingestion of benzodiazepines and antidepressants with quetiapine 5
- Use of quetiapine in combination with other medications 5
Special Considerations
- Quetiapine may lead to severe poisoning, and patients and practitioners should be aware of this when quetiapine is prescribed 5
- The use of off-label low-dose quetiapine for sedative or hypnotic purposes should be discouraged due to the increased risk of major adverse cardiovascular events 3
- Quetiapine treatment was associated with significant improvement of clinical global impression, quality of life, sleep quality, anxiety, and functioning in patients with acute bipolar depression 6