Quetiapine ER 400mg Tablets

Quetiapine is an atypical antipsychotic that exhibits antagonism at multiple neurotransmitter receptors. Its antipsychotic activity is thought to be mediated through a combination of antagonism at dopamine D2 and serotonin 5-HT2A receptors. It also has high affinity for histamine H1 receptors and adrenergic alpha1 and alpha2 receptors, which may contribute to some of its side effects (e.g., sedation, orthostatic hypotension). It also acts as a partial agonist at 5-HT1A receptors and has affinity for serotonin 5-HT2C, 5-HT6, 5-HT7, and muscarinic M1 receptors.

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:

Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of low thyroid levels, including:
+ Constipation
+ Sensitivity to cold
+ Memory problems
+ Mood changes
+ Burning, numbness, or tingling sensations
Severe dizziness or fainting
Chest pain or pressure, rapid heartbeat, or irregular heartbeat
Difficulty controlling body movements, twitching, balance problems, trouble swallowing or speaking
Shakiness, difficulty moving around, or stiffness
Drooling
Seizures
Changes in vision
Severe constipation or stomach pain, which may indicate a serious bowel problem
Difficulty urinating
Flu-like symptoms
Enlarged breasts, nipple discharge, erectile dysfunction, or menstrual changes
Tardive dyskinesia, a severe muscle problem that may cause involuntary movements, particularly in people with diabetes and older adults, especially older females. The risk increases with longer use or higher doses, but can also occur with short-term use or low doses. If you experience trouble controlling body movements or problems with your tongue, face, mouth, or jaw, such as tongue protrusion, puffing cheeks, mouth puckering, or chewing, contact your doctor immediately.

Other Possible Side Effects

Like all medications, this drug can cause side effects, although many people may not experience any or may only have mild symptoms. If you notice any of the following side effects or any other unusual symptoms, contact your doctor or seek medical attention if they bother you or persist:

Dizziness, drowsiness, fatigue, or weakness
Headache
Nervousness or excitability
Sleep disturbances
Constipation
Dry mouth
Increased appetite
Weight gain
Upset stomach or vomiting
Stomach pain
Back pain
Nasal congestion

This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
Certain health conditions, including:
+ Low levels of potassium or magnesium in your blood.
+ A history of abnormal heart rhythms, such as a prolonged QT interval on an electrocardiogram (ECG).
If you are taking any medications that can cause abnormal heart rhythms, including those that may prolong the QT interval. There are many drugs that can have this effect, so it is crucial to ask your doctor or pharmacist if you are unsure.

This list is not exhaustive, and it is vital to discuss all your medications and health conditions with your doctor. Please provide your doctor and pharmacist with a comprehensive list of:

All prescription and over-the-counter (OTC) medications you are taking.
Any natural products or vitamins you are using.
Your complete medical history, including any health problems you have or have had.

Before starting, stopping, or changing the dose of any medication, including this one, you must consult with your doctor to ensure your safety.

Important Warnings and Cautions for Patients Taking This Medication

If you are taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, about your treatment.

Precautions to Avoid Adverse Effects

To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying position. Be cautious when climbing stairs. Additionally, avoid driving or engaging in activities that require alertness until you understand how this medication affects you.

Potential Side Effects and Risks

Rarely, cataracts may occur in patients taking this medication. Furthermore, this medication may increase the risk of developing high blood sugar, diabetes, high cholesterol, and weight gain, which can contribute to heart and brain blood vessel disease.

Monitoring for High Blood Sugar

Be aware of the signs of high blood sugar, such as confusion, drowsiness, unusual thirst or hunger, frequent urination, flushing, rapid breathing, or fruity-smelling breath. If you experience any of these symptoms, notify your doctor promptly.

Risk of Infection

Drugs like this one may cause a decrease in white blood cell count, increasing the risk of infection. In rare cases, these infections can be life-threatening. Inform your doctor if you have a history of low white blood cell count. If you develop signs of infection, such as fever, chills, or sore throat, contact your doctor immediately.

Neuroleptic Malignant Syndrome (NMS)

A rare but potentially life-threatening condition called neuroleptic malignant syndrome (NMS) may occur. Seek medical attention immediately if you experience fever, muscle cramps or stiffness, dizziness, severe headache, confusion, changes in thinking, rapid heartbeat, irregular heartbeat, or excessive sweating.

Dizziness, Sleepiness, and Falls

This medication may cause dizziness, sleepiness, and impaired balance, which can increase the risk of falls and subsequent injuries, such as fractures. Exercise caution to avoid accidents.

Constipation and Bowel Blockage

Constipation is a common side effect of this medication. In rare cases, bowel blockage may occur, which can be life-threatening when combined with other medications that slow gastrointestinal movement. If you have concerns, discuss them with your doctor.

Special Considerations for Older Adults

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects. Additionally, older adults with dementia who take medications like this one have a higher risk of stroke, which can be fatal. This medication is not approved for treating dementia-related mental health issues.

Pregnancy, Fertility, and Breastfeeding

This medication may affect fertility, but this effect is reversible when the medication is discontinued. If you have questions, consult your doctor. Inform your doctor if you are pregnant, plan to become pregnant, or are breastfeeding, as you will need to discuss the benefits and risks to you and your baby. Taking this medication during the third trimester of pregnancy may cause side effects or withdrawal symptoms in the newborn.

Pediatric Patients

If the patient is a child, use this medication with caution, as the risk of certain side effects may be higher in children. Monitor your child's blood pressure regularly, as high blood pressure has been reported in children and teenagers taking this medication. Follow your child's doctor's instructions for blood pressure checks.

• Strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, erythromycin, protease inhibitors, nefazodone): May significantly increase quetiapine levels, leading to increased side effects. Reduce quetiapine dose by 1/6th.
• Strong CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, barbiturates, St. John's Wort): May significantly decrease quetiapine levels, leading to loss of efficacy. May need to increase quetiapine dose up to 5 times.

• CNS depressants (e.g., alcohol, benzodiazepines, opioids): Increased risk of sedation and respiratory depression.
• Antihypertensives: Increased risk of orthostatic hypotension.
• Drugs that prolong QT interval (e.g., Class IA and III antiarrhythmics, some antipsychotics, moxifloxacin): Increased risk of QTc prolongation and arrhythmias.
• Anticholinergic drugs: Increased risk of anticholinergic side effects (e.g., dry mouth, constipation, urinary retention).

• Grapefruit juice: May inhibit CYP3A4, leading to modest increase in quetiapine levels. Avoid large amounts.

• Excessive sedation/somnolence
• Dizziness/lightheadedness (especially on standing)
• Dry mouth
• Constipation
• Blurred vision
• Urinary retention
• Muscle stiffness, tremors, restlessness (akathisia)
• Involuntary movements (especially of face, tongue, limbs)
• Fever, muscle rigidity, altered mental status (NMS symptoms)
• Sore throat, fever, signs of infection (neutropenia)
• Increased thirst, urination, hunger (hyperglycemia)
• Changes in vision (cataracts)

Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Neonates exposed to antipsychotic drugs during the third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery.

Quetiapine and its active metabolite are excreted into human milk. Weigh the benefits of breastfeeding against the potential risks to the infant. Monitor breastfed infants for sedation, irritability, poor feeding, and developmental milestones.

Safety and effectiveness of Quetiapine ER have not been established in pediatric patients. Immediate-release quetiapine is approved for schizophrenia and bipolar mania in adolescents (10-17 years for bipolar mania, 13-17 years for schizophrenia), but ER formulation is generally not used due to lack of specific studies and potential for higher side effect burden.

Increased risk of mortality in elderly patients with dementia-related psychosis (Black Box Warning). Increased risk of orthostatic hypotension, falls, and metabolic side effects. Use lower initial doses and titrate slowly. Monitor closely for adverse effects.

• Quetiapine ER is taken once daily, typically in the evening, to minimize daytime sedation.
• Do not crush or chew ER tablets; this will release the entire dose at once, leading to higher peak levels and increased side effects.
• Metabolic monitoring (weight, glucose, lipids) is crucial due to the risk of metabolic syndrome.
• Orthostatic hypotension is common, especially during initiation and dose titration; advise patients to rise slowly.
• Consider dose reduction or alternative agents if significant weight gain or metabolic abnormalities occur.
• Be aware of the Black Box Warnings regarding increased mortality in elderly patients with dementia-related psychosis and increased suicidality risk in young adults.
• CYP3A4 inhibitors and inducers significantly impact quetiapine levels; dose adjustments are often necessary.

• Other atypical antipsychotics (e.g., Aripiprazole, Olanzapine, Risperidone, Ziprasidone, Lurasidone, Cariprazine, Brexpiprazole)
• Mood stabilizers (e.g., Lithium, Valproate, Lamotrigine) for bipolar disorder
• Antidepressants (e.g., SSRIs, SNRIs) for major depressive disorder (often used in combination with an atypical antipsychotic for adjunctive treatment)

If your symptoms or health problems do not improve or worsen over time, it is essential to contact your doctor for further evaluation and guidance. To ensure your safety and the effectiveness of your treatment, never share your medication with others or take someone else's medication.

This medication is accompanied by a Medication Guide, which is a patient fact sheet that provides crucial information about its safe use. It is vital to read this guide carefully and review it again whenever your prescription is refilled. If you have any questions or concerns about this medication, do not hesitate to consult with your doctor, pharmacist, or other healthcare provider.

In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide detailed information, including the name of the medication taken, the amount consumed, and the time it occurred. This information will help healthcare professionals provide you with the most appropriate care and treatment.