Your guide to medication Quetiapine

Many people say that it takes four to six weeks for quetiapine to show its full effect. However, some people experience benefits sooner than this.

You should stay in touch with your doctor to see how it goes over the first few weeks. They might do some tests to check your symptoms.

If you have had no good effects after two to three weeks, your doctor may increase the dose or change the medicine.

Your doctor will start with a low dose, which they will increase slowly until you find a dose that is effective for you. This may take several days or weeks.

Some studies have shown a risk of developing diabetes among young people taking quetiapine who have a family history of diabetes. This could be linked to putting on weight, which can also be a side effect of taking quetiapine.

Watch out for any early signs of diabetes. These include:

• wanting to drink a lot
• going for a wee a lot
• feeling weak

If you are a young person who already has diabetes, taking quetiapine may affect your blood sugar levels.

Talk to your doctor and check your blood glucose levels regularly.

You may have to increase the dosage of the medication you use for your diabetes.

A side effect of quetiapine can be either weight loss or weight gain. Weight gain is more common than weight loss.

It is very difficult to know how it will affect each person who takes it, but if you start to have problems with your weight while taking quetiapine, talk to your doctor or pharmacist about this.

If you put on weight while taking this medication, and this bothers you, talk to your doctor about other similar medicines you could try. You could also discuss managing your weight through diet and exercise.

You may want to let your family and friends know you are taking quetiapine so they can support you and help you look out for side effects.

For guidance on this, check out our page on getting support with your medication.

In the first few days of taking quetiapine, you may feel extremely sleepy.

Taking quetiapine with alcohol or some other medicines could make this even worse.

If you have been taking quetiapine for a few weeks, and you feel very sleepy, you should go back to your doctor to see if there is something else that you can try.

Quetiapine can also cause sleep-talking, sleep-walking, and some people have done other activities while they were asleep, like eating.

You might also have strange dreams or nightmares.

Talk to your doctor if any of this worries you.

Alcohol

You can continue to drink alcohol while taking quetiapine, but having the two together might make you very sleepy.

During the first few days, it might be best to stop drinking alcohol until you see how the medicine affects you.

If you want to drink alcohol, remember that you might be sleepy and make sure you can get home safely.

Street drugs

Some street drugs can increase levels of dopamine in the brain (e.g. cocaine and ecstasy). As antipsychotics block the effects of dopamine, the 'high' from street drugs may not be as 'high' as before. You may therefore be tempted to increase the dose of your street drug to make up for it, but this could be dangerous.

Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis. For more information, have a look at our drugs and alcohol page.

Some street drugs can make you feel sleepy and this could be made worse with quetiapine.

Quetiapine can enhance the effects of some street drugs and has itself been abused for this purpose. Do not share your quetiapine with anyone else.

Quetiapine does not mix well with some other medicines and drugs.

Always talk to the doctor if you are taking other medicines. Tell the pharmacist you are taking quetiapine if you buy medicines (including things you put on your skin) for common illnesses.

Do not drink grapefruit juice while you are taking quetiapine, as it can increase the amount of drug absorbed from the gut.

Taking quetiapine may make you feel tired or dizzy, and may affect your eyesight when you start taking it.

This could affect you if you drive a car, ride a bike, or do anything else that needs a lot of focus. It might be best to stop doing these things for the first few days, until you know how it affects you.

Do not worry - most people drive as normal while taking quetiapine.

You must tell The DVLA (Driver and Vehicle Licensing Agency) if you have bipolar disorder, schizophrenia, schizoaffective disorder or other mental health conditions that could affect your driving.

You can be fined up to £1,000 if you do not tell DVLA about a medical condition that affects your driving.

You may be prosecuted if you are involved in an accident as a result.

Pregnancy

When deciding whether to take quetiapine during pregnancy it is important to weigh up how necessary quetiapine is to your health against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are.

Quetiapine is not seen as high risk and has a low rate of transfer across the placenta into a baby.

There does not appear to be an increased risk of malformations, miscarriages or having a baby born early.

From month four of a pregnancy onwards, an increase in dose of quetiapine may be required to keep body levels the same.

Quetiapine may slightly increase your chance of getting high blood pressure linked to pregnancy (pre-eclampsia), putting on extra weight and gestational (pregnancy-linked) diabetes.

To reduce the chance of a blood clot in your leg you may be advised to have a course of blood-thinning injections. Your doctor can advise you about this.

Post-natal

If you take quetiapine close to delivery your baby may have some side effects or discontinuation symptoms, like being irritable, crying or problems feeding and sleeping. These are usually mild and go away within a few days without treatment.

Breastfeeding

Quetiapine is passed in small amounts to the baby through breast milk. Breastfeeding may help with any discontinuation symptoms.

You should discuss the risks and benefits of breastfeeding with your midwife or doctor.

Remember that it is important for you to remain well while you are bonding with and looking after your baby. For this reason, it may be best to take medicine for your mental health when breastfeeding.

Make sure that your doctor, nurse, or health visitor checks your baby for any side effects.

If your baby was premature or has health problems, then you will need to be extra careful about taking medicines while breastfeeding. It may be best not to breastfeed if this is the case, but you should discuss this with your doctor or midwife.

Sex

Quetiapine can have side effects that might affect your sex life. These should pass within a couple of weeks. If not, go back and see your doctor as there are other medications you can try.  

Sexual side effects are rare but can include:

• not feeling like you want to have sex
• swelling of the breasts and (very rarely) some milk flow, regardless of gender
• changes to your period
• getting a painful erection that could last a long time (priapism). If this happens to you, seek medical advice immediately as it is dangerous

Fertility

There is nothing to suggest that quetiapine affects fertility.

Quetiapine is not a banned substance in sport.

It can, however, produce a false positive test for methadone or tricyclic antidepressants on a urine drug screen.

You could also feel very sleepy, have blurred vision, or feel less alert when you start taking it. This might affect your performance in sports where you need a lot of focus.

You should not participate in sports where you need to focus until you know how quetiapine affects you.

Do not worry - most people play sports as normal while taking quetiapine.

Try not to take quetiapine for the first time just before your exams.

You might feel very sleepy, have blurred vision or not feel as alert as usual.

You should talk to your doctor about any future exams if you are starting quetiapine.

You might decide together to delay starting it until you have done them.

If they are more than a month away, however, you might find that it is better to start quetiapine to improve your motivation to study.

Do not worry - most people take exams as normal while taking quetiapine.