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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Quetiapine
Generic Name
Quetiapine
Active Ingredient
QuetiapineCategory
Atypical Antipsychotic [EPC]
Salt Form
Fumarate
Variants
108
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Quetiapine, you must consult a qualified healthcare professional.
| 200 mg/1 | TABLET, FILM COATED | ORAL | 71610-702 |
| 200 mg/1 | TABLET, FILM COATED | ORAL | 76420-518 |
| 100 mg/1 | TABLET, FILM COATED | ORAL | 16729-147 |
| 100 mg/1 | TABLET, FILM COATED | ORAL | 0093-8162 |
| 50 mg/1 | TABLET, FILM COATED | ORAL | 0093-8166 |
| 150 mg/1 | TABLET, EXTENDED RELEASE | ORAL | 29300-309 |
| 300 mg/1 | TABLET, EXTENDED RELEASE | ORAL | 29300-311 |
| 400 mg/1 | TABLET, FILM COATED | ORAL | 0904-6643 |
| 150 mg/1 | TABLET, FILM COATED, EXTENDED RELEASE | ORAL | 51407-800 |
+ 38 more variants
Detailed information about Quetiapine
Quetiapine is a second-generation atypical antipsychotic used primarily for the treatment of schizophrenia, bipolar disorder, and as an adjunctive therapy for major depressive disorder. It functions by modulating dopamine and serotonin receptors in the central nervous system.
Dosage for quetiapine is highly individualized based on the condition being treated, the patient's response, and their tolerability.
Quetiapine is approved for specific uses in children and adolescents, but use must be monitored closely due to the risk of weight gain and metabolic changes.
Dosage adjustments are generally not required for patients with kidney disease, as renal clearance of quetiapine is a minor pathway. However, patients should still be monitored for general tolerability.
Because quetiapine is extensively metabolized by the liver, patients with known liver impairment (e.g., cirrhosis) should start at a lower dose, typically 25 mg per day. The dose should be increased slowly, by 25 mg to 50 mg increments daily, until an effective dose is reached.
Older adults (65+) are often more sensitive to the sedative and hypotensive effects of quetiapine. Healthcare providers typically start elderly patients at 25 mg per day and titrate more slowly than in younger adults.
If you miss a dose, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose and resume your regular schedule. Do not 'double up' or take two doses at once to make up for a missed one, as this increases the risk of toxicity.
Signs of a quetiapine overdose may include severe drowsiness, rapid heartbeat (tachycardia), low blood pressure (hypotension), seizures, or fainting. In severe cases, coma or death can occur. If an overdose is suspected, contact your local poison control center or seek emergency medical attention immediately.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop the medication without medical guidance, as sudden discontinuation can lead to withdrawal symptoms or a relapse of your condition.
Many patients starting quetiapine will experience some degree of side effects, particularly during the first few weeks of treatment as the body adjusts.
Quetiapine is a potent medication that affects the central nervous system. It requires careful medical supervision and regular monitoring to ensure safety. Patients should never share this medication with others, even if they have similar symptoms.
Dementia-Related Psychosis: Clinical trials have shown that elderly patients with dementia who take atypical antipsychotics have a higher rate of death, primarily due to cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) causes. Quetiapine is not indicated for this population.
Suicidality in Young Adults: While quetiapine can treat depression, it may also increase suicidal thoughts in those under 25 during the initial months of treatment. Families and caregivers should watch for agitation, irritability, or unusual changes in behavior.
There are several drugs that should never be combined with quetiapine due to the risk of severe, life-threatening interactions:
Quetiapine is strictly contraindicated in the following circumstances:
These are conditions where the drug should generally be avoided unless the potential benefits clearly outweigh the risks:
Quetiapine is classified as Pregnancy Category C (under the old FDA system). There are no adequate and well-controlled studies in pregnant women.
Quetiapine is excreted into human breast milk in very small amounts. While the levels are generally considered low (less than 1% of the mother's weight-adjusted dose), the long-term effects on the developing infant's nervous system are unknown. If a mother must take quetiapine while breastfeeding, the infant should be monitored for excessive drowsiness, irritability, and developmental milestones.
Quetiapine's therapeutic effect is primarily attributed to its dual antagonism of Serotonin (5-HT2A) and Dopamine (D2) receptors. It has a significantly higher affinity for 5-HT2A receptors than for D2 receptors, which is a hallmark of atypical antipsychotics.
Furthermore, its active metabolite, norquetiapine, has high affinity for the Norepinephrine Transporter (NET). By inhibiting the reuptake of norepinephrine, norquetiapine increases the availability of this neurotransmitter in the synaptic cleft, which is believed to be the primary driver of quetiapine's effectiveness in treating depression.
Common questions about Quetiapine
Quetiapine is an atypical antipsychotic medication primarily FDA-approved to treat schizophrenia, bipolar disorder (including manic, mixed, and depressive episodes), and as an add-on treatment for major depressive disorder. It works by balancing neurotransmitters like dopamine and serotonin in the brain to improve mood, thinking, and behavior. Some doctors may also prescribe it off-label for conditions such as severe insomnia or anxiety, though these are not its primary intended uses. Because it has a broad range of effects, the specific dose prescribed will depend on the condition being treated. Always use this medication under the strict guidance of a psychiatrist or healthcare provider.
The most frequently reported side effects of quetiapine include significant drowsiness (somnolence), dry mouth, weight gain, and dizziness. Many patients also experience a 'hangover' feeling or grogginess the morning after taking a dose, especially when first starting the medication. Other common issues include constipation, increased appetite, and a drop in blood pressure when standing up, which can cause lightheadedness. While many of these side effects are manageable, weight gain and metabolic changes (like increased blood sugar) require long-term monitoring by a doctor. If side effects become severe or include muscle stiffness or high fever, you should seek medical attention immediately.
No, you should strictly avoid drinking alcohol while taking quetiapine. Both alcohol and quetiapine are central nervous system depressants, meaning they slow down brain activity. Combining them can lead to extreme drowsiness, severely impaired coordination, and dangerous respiratory depression (slowed breathing). Alcohol can also worsen the orthostatic hypotension caused by quetiapine, significantly increasing your risk of fainting and falling. Furthermore, alcohol can interfere with the management of the underlying mental health conditions for which quetiapine was prescribed. Discuss any history of alcohol use with your doctor before starting this medication.
The safety of quetiapine during pregnancy is not fully established, and it should only be used if the potential benefits to the mother outweigh the risks to the fetus. Research suggests that infants exposed to antipsychotics like quetiapine during the third trimester may experience withdrawal symptoms or extrapyramidal symptoms (movement disorders) after birth. These symptoms can include agitation, tremors, or difficulty feeding. However, untreated mental illness during pregnancy also carries significant risks for both the mother and the baby. If you are pregnant or planning to become pregnant, consult your doctor to discuss a management plan, and consider joining a pregnancy registry to contribute to safety data.
The timeline for quetiapine's effectiveness depends on the symptoms being treated. For sleep or acute agitation, the sedative effects may be felt within the first few days of starting the medication. However, for the treatment of schizophrenia or bipolar mania, it typically takes 2 to 4 weeks of consistent use to see a significant improvement in symptoms. The full therapeutic effect for depression or complex mood stabilization may take up to 6 weeks. It is crucial to continue taking the medication as prescribed, even if you do not feel better immediately, as the brain needs time to adjust to the neurochemical changes.
You should never stop taking quetiapine suddenly without consulting your healthcare provider. Abruptly discontinuing this medication can lead to 'discontinuation syndrome,' which includes symptoms like nausea, vomiting, insomnia, headache, and irritability. More importantly, stopping the drug suddenly increases the risk of a 'rebound' effect, where your original symptoms of psychosis, mania, or depression return quickly and sometimes more severely. Your doctor will provide a gradual tapering schedule, slowly lowering your dose over several weeks or months to allow your brain to adjust safely. Always follow the professional medical plan for stopping any antipsychotic medication.
If you miss a dose of quetiapine, take it as soon as you remember. However, if it is nearly time for your next scheduled dose, you should skip the missed dose and simply take the next one at your regular time. Never take two doses at once to 'catch up,' as this significantly increases the risk of severe sedation, low blood pressure, and other toxic effects. If you find yourself frequently forgetting doses, consider using a pill organizer or setting a daily alarm. Consistency is key to the effectiveness of quetiapine, so discuss any difficulties with adherence with your pharmacist or doctor.
Yes, weight gain is one of the most common and significant side effects associated with quetiapine. This occurs because the medication can increase appetite and cause changes in the body's metabolism. Clinical studies have shown that a significant percentage of patients experience a weight increase of 7% or more of their body weight during long-term treatment. Because weight gain can lead to other health problems like diabetes and heart disease, it is important to monitor your weight, eat a balanced diet, and engage in regular physical activity. Your doctor will also perform regular blood tests to monitor your blood sugar and cholesterol levels while you are on this medication.
Quetiapine has many potential drug interactions, some of which can be dangerous. It is particularly sensitive to drugs that affect the CYP3A4 liver enzyme; for example, certain antifungals or antibiotics can cause quetiapine levels to skyrocket to toxic levels. It can also interact with other medications that cause drowsiness, such as opioids or sleep aids, and drugs that affect heart rhythm. Because of these risks, it is vital to provide your doctor and pharmacist with a complete list of all prescription drugs, over-the-counter medicines, vitamins, and herbal supplements you are taking. They will check for interactions and adjust your treatment plan to ensure your safety.
Yes, quetiapine is widely available as a generic medication in both immediate-release (IR) and extended-release (XR) formulations. Generic versions are required by the FDA to have the same active ingredient, strength, dosage form, and route of administration as the brand-name versions (Seroquel and Seroquel XR). Generic quetiapine is typically much more affordable than the brand-name versions and is covered by most insurance plans. While the inactive ingredients (like fillers or dyes) may differ slightly between manufacturers, the clinical effect should be identical. If you have concerns about switching between different generic brands, discuss them with your pharmacist.
Other drugs with the same active ingredient (Quetiapine)
> Warning: Stop taking Quetiapine and call your doctor immediately or seek emergency care if you experience any of the following:
Quetiapine carries two significant FDA Black Box Warnings:
Report any unusual symptoms or changes in mood to your healthcare provider immediately.
To ensure your safety while taking quetiapine, your healthcare provider will likely order the following tests:
Quetiapine causes significant sedation and can impair judgment, thinking, and motor skills. Do not drive a car, operate heavy machinery, or engage in dangerous activities until you know how the medication affects you. For many, this impairment is most severe in the first two weeks of treatment.
Alcohol should be strictly avoided while taking quetiapine. Alcohol increases the sedative effects of the drug, which can lead to dangerous levels of respiratory depression, extreme dizziness, and an increased risk of falls or accidents.
Do not stop taking quetiapine abruptly. Sudden discontinuation can cause 'discontinuation syndrome,' with symptoms including nausea, vomiting, insomnia, headache, diarrhea, dizziness, and irritability. Furthermore, stopping the drug suddenly can cause a rapid return of psychotic or manic symptoms. Your doctor will provide a tapering schedule to slowly reduce the dose over several weeks.
> Important: Discuss all your medical conditions, especially heart problems, liver disease, or a history of low white blood cell counts, with your healthcare provider before starting Quetiapine.
Quetiapine can cause false-positive results on urine drug screens for methadone or tricyclic antidepressants (TCAs). If you are required to take a drug test, inform the laboratory that you are taking quetiapine so that a more specific confirmatory test (like GC/MS) can be performed.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. A complete list is essential to prevent dangerous interactions.
While quetiapine is chemically distinct, patients who have had severe adverse reactions to other dibenzothiazepine derivatives (like clozapine) should be monitored closely for similar reactions, although direct cross-allergy is rare.
> Important: Your healthcare provider will evaluate your complete medical history, including any previous drug reactions, before determining if Quetiapine is safe for you.
Quetiapine is FDA-approved for schizophrenia in adolescents (13-17) and for bipolar mania in children (10-17). It is NOT approved for use in children under 10.
In patients with renal impairment (CrCl < 30 mL/min), the clearance of quetiapine is not significantly altered. No specific dose adjustment is required, but clinical monitoring for side effects is always advised.
Quetiapine is extensively metabolized by the liver. In patients with liver impairment (Child-Pugh Class A or B), the plasma concentration of quetiapine can be 30% higher than in healthy individuals.
> Important: Special populations require individualized medical assessment and more frequent monitoring by a specialist.
| Parameter | Value |
|---|---|
| Bioavailability | 100% (relative to oral solution) |
| Protein Binding | 83% |
| Half-life | 6-7 hours (Quetiapine); 12 hours (Norquetiapine) |
| Tmax | 1.5 hours (IR); 6 hours (XR) |
| Metabolism | Hepatic (Primarily CYP3A4) |
| Excretion | Renal 73%, Fecal 20% |
Quetiapine is a Second-Generation Antipsychotic (SGA). It is chemically related to clozapine and olanzapine but has a distinct side-effect profile, particularly regarding its lower risk of extrapyramidal symptoms compared to first-generation agents like chlorpromazine.