Quetiapine

Schizophrenia

Quetiapine is used to treat schizophrenia in adults and children who are at least 13 years old. It helps manage symptoms such as hallucinations, delusions, and disorganized thinking.

Bipolar Disorder

This medication is prescribed for several aspects of bipolar disorder in adults and children at least 10 years old:

• Manic episodes: Periods of extreme excitement, overactivity, or irritability.
• Depressive episodes: Periods of extreme sadness or low energy associated with bipolar disorder.
• Maintenance: It may be used long-term, sometimes in combination with other medications like lithium or divalproex, to prevent the return of manic or depressive symptoms.

Major Depressive Disorder

The extended-release version of quetiapine is used as an add-on treatment for adults with major depressive disorder. It is typically prescribed when an antidepressant alone is not providing enough relief from symptoms.

Quetiapine belongs to a class of medications known as atypical antipsychotics. These drugs work by changing the activity of neurotransmitters, which are chemical messengers that allow brain cells to communicate with each other.

The medication is believed to work primarily by affecting two specific neurotransmitters:

• Dopamine: Quetiapine blocks certain dopamine receptors in the brain. Overactivity of dopamine is often linked to symptoms such as hallucinations and delusions.
• Serotonin: The drug also interacts with serotonin receptors. This interaction is thought to help regulate mood, sleep, and anxiety.

While the exact mechanism of action is not completely understood, the way quetiapine rebalances these chemicals helps stabilize mood and improve symptoms in people with conditions such as schizophrenia or bipolar disorder.

Common Side Effects

Many people taking quetiapine experience mild side effects as their body adjusts to the medication. These may include:

• Drowsiness or extreme tiredness
• Dizziness or lightheadedness, especially when standing up quickly
• Dry mouth
• Weight gain and increased appetite
• Constipation
• Stomach pain or upset stomach
• Sore throat or stuffy nose

Serious Side Effects

Some side effects can be severe and require prompt medical evaluation. Seek medical help for:

• Uncontrolled muscle movements in the face, tongue, or limbs (tardive dyskinesia)
• High fever, severe muscle stiffness, sweating, and confusion
• Signs of high blood sugar, such as increased thirst, frequent urination, or blurred vision
• Fainting or a rapid, pounding heartbeat
• Difficulty swallowing
• Seizures
• Changes in vision
• New or worsening mood changes, anxiety, or suicidal thoughts

Quetiapine may also cause changes in cholesterol levels or a decrease in white blood cell counts. Healthcare providers typically monitor these levels through regular blood tests. Because this medication can affect how the body regulates temperature, it is important to avoid becoming overheated or dehydrated.

Boxed Warnings

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Quetiapine is not approved for the treatment of patients with dementia-related psychosis.

Antidepressants may increase the risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Patients of all ages starting this medication should be monitored closely for worsening symptoms, clinical depression, or unusual changes in behavior.

Metabolic Changes

Quetiapine is associated with metabolic risks that require regular monitoring. These include:

• Hyperglycemia and Diabetes: High blood sugar levels can occur, which in some cases may be extreme and lead to ketoacidosis, coma, or death. Individuals with a history of diabetes or risk factors for diabetes should have their blood glucose monitored.
• Dyslipidemia: Changes in cholesterol and triglyceride levels may occur.
• Weight Gain: Significant weight gain is common and should be monitored during treatment.

Movement Disorders

Tardive dyskinesia, a condition involving uncontrollable and repetitive muscle movements (often in the face, tongue, or jaw), may develop. The risk is generally higher with long-term use and in elderly patients, though it can occur at any time. These movements may become permanent.

Neuroleptic Malignant Syndrome (NMS) is a rare but potentially fatal reaction to antipsychotic drugs. Symptoms include high fever, muscle rigidity, altered mental status, and evidence of autonomic instability, such as irregular pulse or blood pressure.

Other Serious Precautions

• Orthostatic Hypotension: This medication can cause a sudden drop in blood pressure when standing up, leading to dizziness, lightheadedness, or fainting, especially during the initial dose adjustment period.
• QT Prolongation: Quetiapine may affect the heart's electrical activity, which can lead to serious heart rhythm disturbances. This risk may be higher when used with certain other medications.
• Blood Cell Counts: Some patients may experience a significant decrease in white blood cell counts (leukopenia, neutropenia, or agranulocytosis), which can increase the risk of infection.
• Seizures: Caution is advised for individuals with a history of seizures or conditions that lower the seizure threshold.
• Cataracts: Lens changes have been observed in some patients; eye examinations may be recommended at the start of treatment and every six months thereafter.
• Body Temperature: Antipsychotics can interfere with the body's ability to reduce core temperature. Caution is recommended for those engaging in strenuous exercise or exposed to extreme heat.

Pregnancy

The safety of quetiapine during pregnancy is not fully known. It should only be used if the potential benefit to the mother outweighs the potential risk to the developing fetus. If you are pregnant or planning to become pregnant, consult your healthcare provider to discuss your treatment options.

Newborns exposed to antipsychotic medications like quetiapine during the third trimester may experience withdrawal symptoms or extrapyramidal symptoms after delivery. These symptoms can include:

• Agitation or tremors
• Muscle stiffness or floppiness
• Difficulty breathing
• Feeding problems
• Excessive sleepiness

A pregnancy exposure registry is available to monitor the health of individuals who take quetiapine during pregnancy and their babies.

Breastfeeding

Quetiapine is known to pass into breast milk. Because of the potential for adverse effects in the nursing infant, a decision must be made whether to stop breastfeeding or stop the medication. This decision should be made in consultation with a healthcare provider, considering the importance of the medication for the mother's health.

Oral Tablet Forms

Quetiapine is administered orally and is available in two primary tablet formulations:

• Immediate-release tablets: This version releases the active ingredient into the system shortly after being swallowed.
• Extended-release tablets: This version is designed to provide a steady release of the medication over a longer period.

Both forms are intended for oral use only and should be taken exactly as directed by a healthcare provider. The choice between immediate-release and extended-release formulations depends on the specific condition being treated and the patient's response to the medication.

FDA Approval and Indications

Quetiapine was first approved by the U.S. Food and Drug Administration (FDA) in 1997. It is currently approved for the treatment of several mental health conditions, including:

• Schizophrenia in adults and adolescents aged 13 to 17.
• Bipolar I disorder, including acute manic episodes in adults and children aged 10 to 17.
• Bipolar depression in adults.
• Maintenance treatment of bipolar I disorder in adults (used alongside lithium or divalproex).
• Major depressive disorder in adults, as an add-on treatment to other antidepressants (specifically the extended-release formulation).

Boxed Warnings

The FDA requires a boxed warning—its most serious type of warning—for quetiapine due to the following risks:

• Increased Mortality in Elderly Patients with Dementia-Related Psychosis: Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Quetiapine is not approved for the treatment of patients with dementia-related psychosis.
• Suicidal Thoughts and Behaviors: In clinical studies, antidepressants increased the risk of suicidal thoughts and behaviors in children, adolescents, and young adults. Patients of all ages who start quetiapine should be monitored closely for clinical worsening or the emergence of suicidal thoughts and behaviors.

Regulatory Status

Quetiapine is available only by prescription. It is not a controlled substance. It is available in both immediate-release and extended-release (ER) formulations, and generic versions are widely available. Because of the potential for metabolic changes, such as high blood sugar and weight gain, the FDA recommends regular monitoring of clinical status while using this medication.

Withdrawal Symptoms

If you stop taking quetiapine abruptly, you may experience withdrawal symptoms. Common symptoms reported after stopping the medication suddenly include:

• Nausea
• Vomiting
• Difficulty falling asleep or staying asleep (insomnia)

Safe Discontinuation

To prevent these symptoms and to avoid a potential worsening of your underlying condition, your doctor will typically recommend a gradual reduction in your dose rather than stopping the medication all at once. This process, often called tapering, allows your body to adjust slowly.

Always follow your healthcare provider's specific instructions for decreasing your dose. Do not stop taking quetiapine or change your dose without medical supervision.