Quetiapine (Seroquel) - Uses, Side Effects, and More

What are the most common side effects of quetiapine?

The most common side effects of quetiapine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

• Feeling unusually weak or tired, 
• Drowsiness, dizziness
• Dry mouth
• Increased appetite or weight gain
• Constipation
• Upset stomach or indigestion
• Low blood pressure upon standing (see below)
• Sore throat or stuffy nose
• Abnormal liver function tests (oral tablets)
• Slurred speech 
• Nausea or vomiting (children)
• Fast heartbeat (children)

There may be other side effects of quetiapine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of quetiapine?

While less common, the most serious side effects of quetiapine are described below, along with what to do if they happen.

Severe Allergic Reactions. Quetiapine may cause allergic reactions, which can be serious. Stop taking quetiapine and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching, skin rash, or pale red bumps on the skin called hives
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Metabolism Problems. Quetiapine can cause high blood sugar levels or diabetes, high cholesterol levels, and weight gain. Very high blood sugar levels can lead to coma or death. Check your weight regularly and tell your healthcare provider if you experience weight gain. Talk with your healthcare provider about how to help limit weight gain, such as by exercising and eating a healthy and balanced diet. Keep all appointments with your healthcare provider to check your blood work and weight. Call your healthcare provider if you gain weight or develop the following symptoms of high blood sugar.

• Thirsty more than usual
• Peeing more than usual
• Increase in hunger
• Tiredness
• Feeling sick to your stomach
• Confusion
• Your breath smelling fruity

Suicidal Thoughts or Actions. Quetiapine or other antidepressants may increase the risk of suicidal thoughts or actions in a small number of children, teenagers, or young adults in the first few months of taking the medicine or when the dose is changed. Depression or other serious mental health conditions are the most important causes of suicidal thoughts or actions. If you or your child is about to harm themselves, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your healthcare provider right away if you have any of the following symptoms.

• New or increased thoughts of suicide or death
• Suicide attempt
• New or increased feelings of anxiety, depression, or other unusual changes in your mood or behavior
• Difficulty sleeping
• Anger, aggression, or violent behavior
• Impulsive behavior
• Exaggerated increase in activity or talking (mania)

Low Blood Pressure Upon Standing (Orthostatic Hypotension). Quetiapine may cause a sudden drop in blood pressure when standing up from a seated or lying position. To help prevent this, be careful not to get up too quickly. If you feel dizzy, sit or lie down right away until the dizziness stops, then take your time getting up again. Tell your healthcare provider right away if you have any of the following symptoms of orthostatic hypotension.

• Dizziness, feeling lightheaded, or fainting upon standing
• Blurred vision
• Confusion
• Feeling weak

Neuroleptic Malignant Syndrome (NMS). Antipsychotic medicines, like quetiapine, can cause a rare but serious condition called neuroleptic malignant syndrome. NMS is a serious condition that can lead to death. Stop taking quetiapine and call your healthcare provider right away if you have any of the following symptoms.

• High fever
• Muscle stiffness or rigidity, where it is hard to move
• Changes in your breathing or heart rate
• Increased sweating
• Confusion

Body Temperature Regulation. Quetiapine can affect your ability to regulate your body temperature. This could make you become very hot, especially in hot weather or after exercising a lot. You should drink water and avoid overheating and dehydration. Call your healthcare provider right away if you are severely ill and have the following symptoms.

• Excessive or no sweating
• Dry mouth
• Feeling very hot
• Feeling thirsty 
• Not able to pee

Uncontrolled Movements. Quetiapine can cause some people to have movements that they cannot control. This condition, called tardive dyskinesia (TD), can cause jerky movements of your face, tongue, or body. TD can be permanent. Call your healthcare provider right away if you have any symptoms of TD.

• Tongue sticking out
• Lip smacking or puckering
• Grimacing
• Rapid eye blinking
• Jerking or twisting motion of the arms, legs, or trunk

Withdrawal Reactions. If you stop quetiapine suddenly, it could lead to withdrawal symptoms, such as nausea, vomiting, or difficulty sleeping. These symptoms usually last about one week. Do not stop taking quetiapine without talking with your healthcare provider. Talk to your healthcare provider about how to stop quetiapine to reduce the risk of withdrawal reactions. 

Trouble Swallowing. Quetiapine can cause trouble swallowing (dysphagia), which can increase your risk of choking while eating or drinking. Eat small amounts of food, and chew your food well. Get emergency help if you are choking or have food stuck in your esophagus that is not passing.

Increased Blood Pressure (Hypertension) in Children and Teenagers. Quetiapine may increase your blood pressure or make it worse if you have a history of high blood pressure. Your healthcare provider may check your blood pressure before you start taking quetiapine. Call your healthcare provider if your blood pressure increases while taking this medicine.

If you measure your blood pressure and the top number (systolic) is 180 mm Hg or higher or the bottom number (diastolic) is 120 mm Hg or higher, get medical attention right away. Increases in blood pressure may not be noticeable but look out for any of the following symptoms of severely high blood pressure.

• Sudden severe headache
• Chest pain
• Dizziness or confusion
• Trouble breathing
• Nausea/vomiting
• Blurry or other changes to vision
• Anxiety
• Buzzing in the ears
• Nosebleed
• Feeling of skipped heartbeats

Blood Disorders. Quetiapine can cause blood disorders, such as agranulocytosis and low white blood cell levels (leukopenia or neutropenia). Stop using quetiapine and get help right away if you have any of the following symptoms of blood disorders.

• Fever
• Shortness of breath
• Pale or yellowish skin
• Easy bruising or bleeding
• Frequent infection
• Unusual weakness or tiredness
• Dizziness, lightheadedness, or feeling like you are about to pass out
• Headache
• Fast or abnormal heartbeat

Seizures. Some people who have taken quetiapine have reported having seizures. There are many different types of seizures and some of them are not easy to recognize. Stop taking quetiapine and call your healthcare provider if you have any of the following signs that a seizure is happening or could happen.

• Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
• Stiffening of your arms and legs
• Feeling anxious, nervous, confused, or a sense of dread
• Feeling dizzy or lightheaded
• Falling or losing consciousness

Decreased Alertness or Coordination and Falls. Quetiapine has several side effects that could affect your alertness or coordination and increase your risk for falls, including dizziness, sleepiness, low blood pressure when you stand up. Talk to your healthcare provider about your fall risk If you are prone to falls or have other medical conditions or medicines that could also increase your risk of falls. Do not drive or do other activities that require alertness or coordination until you know how quetiapine affects you.

Low Thyroid Hormones (Hypothyroidism). Quetiapine can cause the function of your thyroid gland to change, which can lead to low thyroid levels. Keep all appointments to have your blood checked. Tell your healthcare provider if you have any of the following signs of low thyroid hormones. 

• Weight gain
• Feeling cold 
• Tiredness that does not go away or continues to worsen
• Constipation

High Prolactin Level (Hyperprolactinemia). Quetiapine may cause an increased level of the hormone prolactin in your blood. Increased levels of prolactin could lead to fertility or bone problems. Contact your healthcare provider if you have any of the following symptoms.

• Vaginal dryness
• Irregular or no periods 
• Production of breastmilk when not pregnant or nursing
• Inability to get or keep an erection
• Enlarged breast size (gynecomastia)
• Decreased muscle mass and body hair

Cataracts. Taking quetiapine may cause changes in the lens of your eye or lead to cataracts. Talk to your healthcare provider if you notice any changes in vision such as blurriness, difficulty seeing, or faded colors. Be sure to keep all of your appointments, including eye appointments, that your healthcare provider recommends.