Seroquel

Brand Name:Seroquel

Prescription needed: Yes

What is this drug used for?

Quetiapine is used to treat the symptoms of schizophrenia and mania in those with bipolar disorder. Use of quetiapine may help people who are nervous and suffer from hallucinations, hearing voices, seeing things, and unusual suspiciousness.

Quetiapine works by restoring the balance of some natural chemicals in the brain (neurotransmitters).

Is there any reason not to take this drug?

You should not take this drug if you are allergic to olanzapine. Tell your doctor if you have or have ever had:

  • heart disease or high cholesterol
  • dementia
  • seizures
  • stroke
  • Alzheimer’s disease
  • thyroid disease
  • liver disease
  • difficulty urinating
  • glaucoma
  • low blood pressure
  • diabetes or increased blood sugar
  • a condition called neuroleptic malignant syndrome (NMS)
  • a condition called tardive dyskinesia

What about possible side effects?

Some common side effects of quetiapine are:

  • headache
  • sleepiness
  • dry mouth
  • constipation
  • diarrhea
  • stomach upset
  • weight gain and increased appetite
  • tremor

Quetiapine can also cause an increase in blood sugar levels for people with or without diabetes. Some symptoms of high blood sugar are:

  • extreme thirst
  • frequent urination
  • extreme hunger
  • blurred vision
  • weakness

Quetiapine can cause a condition called neuroleptic malignant syndrome (NMS). If you have fever, very stiff muscles, a change in mental function, sweating, or an irregular heartbeat, this is a medical emergency and you must call your doctor immediately.

This drug can also cause a condition called tardive dyskinesia. If you have any uncontrollable jerking movements, or muscle movements you can not control, call your doctor immediately.

Also call your doctor if you experience any of these more serious symptoms:

  • dizziness
  • fainting
  • increased heartbeat
  • seizures
  • increased body temperature
  • difficulty swallowing

This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication, ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as he/she may need to make changes or monitor you more closely:

  • blood pressure medicines - might lower blood pressure more than desired
  • levodopa or other medicines for Parkinson’s disease - quetiapine might work against these medicines
  • carbamazepine, phenytoin and rifampin - these drugs lower the amount of quetiapine in the blood; the dose of quetiapine might need to be increased
  • erythromycin, clarithromycin, fluconazole, itraconazole, ketoconazole - these drugs can raise the amount of quetiapine in the blood; the dose of quetiapine should be decreased
  • diltiazem, verapamil - these drugs can raise the amount of quetiapine in the blood; the dose of quetiapine should be decreased
  • HIV protease inhibitors, indinavir, nelfinavir, ritonavir - these drugs can raise the amount of quetiapine in the blood; the dose of quetiapine should be decreased

Quetiapine can also increase the effects of drugs that cause drowsiness, such as depression or anxiety medications, allergy medications, medications for sleep, pain relievers or muscle relaxants.

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications, vitamins, and herbal supplements).

Other information:

Special instructions: Use of quetiapine for dementia-related behavior problems (e.g. agitation or aggression) in the elderly has been linked to a higher chance of strokes and death. Quetiapine is not approved for dementia-related behaviour problems.

See Health Canada Advisory (June 22, 2005)
http://www.hc-sc.gc.ca/ahc-asc/media/advisories-avis/2005/2005_63_e.html

Taking quetiapine makes it harder for your body to regulate temperature. Try to avoid overheating, becoming dehydrated, and exercising in hot weather while taking quetiapine.

Children: Not recommended for those under 18 years of age.

Seniors: Require a reduced dose.

Pregnant women: Safety in pregnancy not established. Talk to your doctor.

Women who are nursing: Safety not established. Talk to your doctor.

People who drive or operate machinery: You should know how quetiapine will affect you before driving or operating machinery because it can cause drowsiness.

Alcohol: Avoid alcohol if you are taking this drug because it may increase quetiapine’s sedative effects.

Overdose: If you experience any unusual reactions, or if you seriously exceed the recommended dosage, call your doctor or 911.

Stopping the drug: Talk to your doctor before you stop taking this drug as symptoms may return.

If you miss a dose: Take it when you remember. However, if your next dose is within 4 hours, take a single dose when you remember and skip the next. Do not take a double dose.

Storage conditions: Closed container; cool, dry location away from excess moisture (not in the bathroom); always out of reach of children.

Dietary precautions: None.