How does olanzapine work?
Olanzapine belongs to a group of medicines called antipsychotics.
It does not cure your condition, but it can help to improve the symptoms of mental health conditions.
Olanzapine works by affecting naturally occurring chemical messengers in your brain (neurotransmitters), like dopamine.
If you have too much dopamine it can make you see or hear things that are not there (hallucinations), or think things that others do not (delusions). Dopamine is also involved in muscle movements, so too much of it can affect your muscles.
Olanzapine also works on another neurotransmitter called serotonin which is believed to control mood.
Olanzapine rebalances these chemicals to improve your mood and behaviour.
Taking olanzapine will not change your personality and it is not addictive.
When will I feel better?
Olanzapine, like many medicines, does not work straight away. It can take a few weeks to get the dose right for you.
It may take several days or even weeks for some of your symptoms to get better.
How will olanzapine make me feel?
When you first start taking olanzapine, it may make you feel more relaxed and calm. Within 2 to 3 weeks, your other symptoms may start to improve.
You may find olanzapine makes you:
- able to concentrate better, and think more clearly
- able to get things done and stay focused
- remember things more easily
- feel more comfortable with other people and get along with them better
- more aware of what is real and what is not real
- stop hearing voices
Are there any long-term side effects?
Many people take olanzapine for a long time, including for many months or years, without any problems.
Olanzapine can increase the amount of sugar in your blood and this can sometimes lead to diabetes. Keeping to a healthy weight can help to prevent this. It's not a common side effect of olanzapine and affects less than 1 in 100 people.
You'll usually have a blood test before you start taking olanzapine to see how much sugar you have in your blood.
You'll have another test around 12 weeks after starting olanzapine to see if the amount of sugar in your blood has changed. If it's OK, then you'll have a test each year to check your blood sugar.
If you already have diabetes or you're at risk of getting it you'll be monitored more closely and will have more regular blood sugar tests. For example, you may have a test every 4 weeks to start with and then around 4 times a year.
Taking olanzapine for a long time can sometimes affect your cholesterol. If this happens, your doctor may advise you to take a medicine to help lower your cholesterol.
What will happen if I stop taking it?
Olanzapine helps to control your symptoms. Do not stop taking it suddenly as your symptoms may come back.
If you need to stop taking olanzapine, your doctor will help you come off it by reducing your dose gradually. This will help prevent withdrawal symptoms.
Withdrawal symptoms can include:
- feeling or being sick
- sweating
- difficulty sleeping
Talk to your doctor first if you want to go onto a lower dose or to stop taking olanzapine.
How does it compare with other antipsychotic medicines?
The antipsychotic medicine you're prescribed will depend on the type of symptoms you have, how bad your symptoms are, any other medical conditions you have and how well your medicine works for you.
It will also depend on whether it's best for you to take your medicine as tablets or an injection, and whether the medicine has any side effects that may affect you.
You may have to try a few before you find the antipsychotic medicine that is right for you. It can take time to find the right type and dose to manage your symptoms.
Different antipsychotic medicines have different side effects. When deciding on the best medicine for you, it's important to discuss with your doctor what the possible side effects are and how they may affect you.
How does olanzapine compare to lithium for bipolar disorder?
Lithium is usually the first medicine used to treat bipolar disorder. It's a long-term treatment for episodes of mania and depression and is often prescribed for at least 6 months.
Lithium is a mood stabiliser, which means it helps to balance your mood and control symptoms of mania as well as depression.
Olanzapine also helps with symptoms of mania. However, you will need to take it with another medicine to also manage your depression symptoms.
You can discuss with your doctor which treatment will be best for you. It will depend on the type of symptoms you have, any other medical conditions you have and whether you might be more likely to have side effects with some medicines.
Can olanzapine be used to treat anxiety?
There's been some research into using olanzapine for anxiety, but this medicine has not yet been approved as a treatment.
Your doctor will use other medicines as a first choice if you have anxiety.
Will I gain or lose weight?
You will not usually lose weight on olanzapine. It can make you feel more hungry than usual, so you may put on weight.
Try to eat a healthy balanced diet, without increasing your portion sizes.
Do not snack on foods that contain a lot of calories, such as crisps, cakes, biscuits and sweets. If you feel hungry between meals, eat fruit and vegetables and low-calorie foods.
If you're worried about gaining or losing weight while taking olanzapine, talk to your doctor or pharmacist.
Can olanzapine affect my sex life?
Olanzapine is a type of medicine called an antipsychotic. Most antipsychotic medicines can cause sexual problems, but some are more likely to cause problems than others.
If you feel you have a sexual problem of any kind while taking olanzapine, including less interest in sex (reduced libido) or problems getting an erection, talk to your doctor.
Your doctor will be able to help you and may change your treatment so that the sexual problems improve or go away.
Will it affect my contraception?
Olanzapine will not affect any type of contraception, including the combined pill or emergency contraception.
Can I drive or ride a bike?
Olanzapine can make you feel sleepy. If this happens to you, do not drive, ride a bike or use tools or machinery until you feel better.
Some people find it hard to concentrate while they are taking olanzapine. When you first start taking it, it's a good idea to stop driving and cycling for the first few days until you know how the medicine makes you feel.
It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.
Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking olanzapine. GOV.UK has more information on the law on drugs and driving.
Can I drink alcohol while taking olanzapine?
It's best not to drink alcohol for the first few days of treatment, until you see how the medicine affects you.
If you drink alcohol while taking olanzapine it may make you feel sleepy and unsteady.
Drinking alcohol every day or in large amounts can make your symptoms worse. It also makes it harder for olanzapine to work properly.
Is there any food or drink I need to avoid?
Apart from limiting alcohol, you can eat and drink normally while taking olanzapine.
However, olanzapine can make you feel hungrier and put on weight.
If you have an increased appetite, try to eat a healthy balanced diet without increasing your portion sizes.
Do not snack on foods that contain a lot of calories, such as crisps, cakes, biscuits and sweets. If you feel hungry between meals, eat fruit and vegetables and low-calorie foods.