Quetiapine is used to treat certain mental/mood conditions (such as schizophrenia, bipolar disorder, sudden episodes of mania or depression associated with bipolar disorder). Quetiapine is known as an anti-psychotic drug (atypical type). It works by helping to restore the balance of certain natural substances (neurotransmitters) in the brain.
This medication can decrease hallucinations and improve your concentration. It helps you to think more clearly and positively about yourself, feel less nervous, and take a more active part in everyday life. It may also improve your mood, sleep, appetite, and energy level. Quetiapine can help prevent severe mood swings or decrease how often mood swings occur.
Quetiapine may also be used in combination with other medication to treat depression. If you are using quetiapine in combination with other medication to treat depression, carefully read the drug information for the other medication.
Many drugs besides quetiapine may affect the heart rhythm (QT prolongation), including amiodarone, moxifloxacin, procainamide, quinidine, sotalol, thioridazine, among others.
Other medications can affect the removal of quetiapine from your body, which may affect how quetiapine works. Examples include azole antifungals (such as itraconazole, ketoconazole), rifamycins (such as rifampin), drugs used to treat seizures (such as carbamazepine, phenytoin), among others.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
This medication may interfere with certain laboratory tests (including urine tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.
Common side effects of Quetiapine include:
- Upset stomach
- Weight gain
- Blurred vision
- Dry mouth
If any of these effects persist or worsen, tell your doctor promptly.
Dizziness or lightheadedness may occur, especially when you first start or increase your dose of this drug. To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Tell your doctor right away if any of these unlikely but serious side effects occur: restlessness/constant need to move, shakiness (tremor), signs of infection (such as fever, persistent sore throat), mental/mood changes (such as increased anxiety, depression, thoughts of suicide), difficulty swallowing, constipation with persistent abdominal pain.
Get medical help right away if any of these rare but serious side effects occur: fainting, seizure, severe dizziness.
This medication may infrequently make your blood sugar level rise, which can cause or worsen diabetes. Tell your doctor immediately if you develop symptoms of high blood sugar, such as increased thirst and urination. If you already have diabetes, be sure to check your blood sugars regularly. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
This drug may also cause significant weight gain and a rise in your blood cholesterol (or triglyceride) levels. These effects, along with diabetes, may increase your risk for developing heart disease. Discuss the risks and benefits of treatment with your doctor. (See also Notes section.)
Quetiapine may rarely cause a condition known as tardive dyskinesia. In some cases, this condition may be permanent. Tell your doctor immediately if you develop any unusual/uncontrolled movements (especially of the face, lips, mouth, tongue, arms or legs).
This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms: fever, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, change in the amount of urine.
Quetiapine may increase a certain natural substance (prolactin) made by your body. For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor immediately.
Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.