Long-acting injectable (depot) antipsychotics

Long-acting injectable antipsychotics are a special preparation of an antipsychotic medication. They are given by injection.

These injections contain the antipsychotic and a base. This base is either oil or water, and allows the medication to be released into the body over time.

Long-acting injectable antipsychotics are informally known as ‘depot’ medications. This is because the injections create a storage (or depot) of the medication in the injected muscle. This is then slowly released into the body over weeks or months.

There are lots of different medications that can be given by injection (e.g. insulin for diabetes). However, this resource looks specifically at long-acting injectable antipsychotics.

Long-acting injectable antipsychotics are used to treat the symptoms of psychosis. They are often used to help treat:

• schizophrenia
• schizoaffective disorder
• bipolar disorder

Long-acting injectable antipsychotics can also sometimes be used to treat the symptoms of psychosis if they are present in other conditions, such as severe depression. If you are not sure why your doctor is suggesting that you take a long-acting injectable antipsychotic, ask them to explain why they feel it would be useful.

You might also take other medications at the same time as taking a long-acting injectable antipsychotic. For example, if you have schizoaffective disorder, you might also take a mood stabiliser. You might take this as a tablet or a liquid.

The medication going into your body by a long-acting injectable is exactly the same as the medication going into your body in tablet form. The only differences are:

• the route through which the medication enters
• the amount of the drug you are given. This is because the drug is slowly released over time, so there needs to be more of it.

This means that the benefits and the side-effects of the depot injection are the same as they would be if you took the medication by mouth.

If you have a long-acting injectable antipsychotic, you will usually go into a private room with the nurse or doctor. They will usually give you the injection in your arm, thigh or buttock, depending on the type of medication.

After each injection the medication stays in your body for a few weeks or months. This will depend on the type and dose of antipsychotic you are having.

Before you have a long-acting injectable antipsychotic for the first time, you may need to have one of the following things:

• A test dose – This is a one-off injection that you will be given to check that you are not sensitive to the medication or the oily base. If you are not sensitive to the test dose, you will usually be given your first full treatment dose seven days later.
• A short-acting injectable - This is one or two doses of your medication given one day after the other. It contains the same ingredient as a long-acting injectable but releases into the body immediately rather than slowly. If you have no negative reactions when given these injectables, you will then be given the full treatment dose.
• A tablet version of the medication

If you are sensitive to the medication or the oily base, you might be more likely to develop some of the common side-effects associated with the medication you are taking. You can find out more about these in our antipsychotics resource. Or you might have an allergic reaction.

By giving you a test dose, the people treating you can identify any issues, and help you to adapt your treatment plan. 

Some of the substances contained in the injections are quite thick. Because of this they need to be given into a large muscle, so that there is less (or no) pain and swelling. You can talk to your doctor or your nurse about whether it is best to have your injection in your buttock, thigh or arm.

Some medications can only be given in certain locations, so this might affect which location you can choose.

If you are not in hospital, you can usually decide yourself where to have your injections. The choices might include:

• your doctor's surgery 
• a community mental health centre
• an out-patient clinic
• your home.

For some types of injection, you will need to be monitored afterwards. Because of this you might need to go to a particular place to get your injection so that this can happen. You can discuss this with your clinician.

You will need to get a long-acting injectable between once a week and once every six months. It is most common to get an injection every four weeks.

How long these injections last will depend on your illness and the medication you are taking. You should discuss this with your doctor.

You can find out more about the medication you are taking by talking with a pharmacist or by reading the Patient Information Leaflet that comes with your medication. Your doctor or nurse should give you this when you get your long-acting injectable. You can also ask to read this before choosing your medication, or when you receive the injection.

Long-acting injectables are released slowly into the body, so it can take a little while until they start working properly. If you were taking tablet antipsychotics, you might be told to continue taking these for a short time when you first start having a long-acting injectable. This will be until your long-acting injectable has reached its full effectiveness. The person prescribing your medication will tell you if you need to do this.

The person prescribing your medication should work with you to decide which long-acting injectable is best for you.

All long-acting injectable antipsychotics are generally similar in how well they work. However, there are some slight differences in the effects they have, just as there are in different antipsychotic tablets. For example, zuclopenthixol may be more suitable if you are very agitated. Or flupentixol may be more suitable if you have a low mood associated with your illness.

There are also differences in the side-effects different medications can cause. This will probably influence how you and your doctor decide which one you should take.

Different antipsychotics need to be given at different frequencies. For example, one might need to be given every four weeks, while another might need to be given every three months. This might influence your decision making around which antipsychotic you take.

There is a common misconception that long-acting injectable antipsychotics are only given to people who are too mentally unwell to consent to treatment.

Some people need to be given long-acting injectable antipsychotics when they are very unwell and in hospital. Or when they are too unwell to consent to treatment.

However, some people choose long-acting injectable antipsychotics over other options like tablets.

The positives and negatives of being prescribed a long-acting injectable antipsychotic might include some of the following things.

Positives

• You won’t have to remember to take your medication every day.
• You are less likely to forget your medication, so you are less likely to get ill.
• The medication in long acting injectables stays in your body for longer than tablets when you stop taking them, which will make you less likely to relapse (become unwell again).
• They can be helpful if you find it hard to swallow tablets.
• There is strong evidence to suggest that long-acting injectable antipsychotics prevent people with psychotic illnesses like schizophrenia and schizoaffective disorder from relapsing. This can make it easier for you to get back to doing the things you used to do before you became unwell, like work and socialising.

“It’s easier for me to have an injection once a month … especially with the sleep pattern that I’ve got. If I go on a night out and then I end up staying over at someone’s house, I don’t have to be worrying about whether I’ve got my tablets. From a convenience point of view an injection at the GPs once a month is a lot easier to manage.” Michael

Negatives

• You might feel uncomfortable with the idea of having injections. This can be for a lot of different reasons, from anxiety about needles to more general discomfort with the idea of having an injection. Having an injection can understandably feel like a ‘bigger deal’ than taking a tablet.
• Long-acting injectables last for longer than tablets of the same medication, and this can mean you have less control over when you do and don’t take your medication. While this can be beneficial for your health, it might make you feel like you have lost some control over your care.
• Some people experience pain from the injection which can last for a few days. This is usually mild.

Having a long-acting injectable is a personal decision, and whatever feelings you have are legitimate.

The side-effects of long-acting injectable antipsychotics are the same as with the tablet version of the same drug. This is because both contain the same medication and work in similar ways.

However, there are some temporary side-effects related to the injection. Around 1 in 10 people experience:

• pain
• minor bleeding from the injection site
• a temporary nodule, or skin thickening, where the injection was given.

Some long-acting injectable antipsychotics belong to the older group of antipsychotics. These are also called 'first generation' antipsychotics, and include:

• flupentixol decanoate
• haloperidol decanoate
• zuclopenthixol decanoate.

Newer or 'second generation' antipsychotics include:

• risperidone
• paliperidone palmitate
• olanzapine pamoate monohydrate
• aripiprazole

This list doesn’t necessarily cover all antipsychotics. Newer medications might become available at any time. Remember, these drugs will have different ‘brand’ names.

Older antipsychotics are more likely to cause side-effects when compared to newer ones. These side-effects can vary depending on the medication, but can include stiffness or shaking in your arms and legs. This is also true for the tablet forms of these medications.

Very rarely, the injection is accidentally injected into a vein rather than a muscle. If this happens, or the person administering your injection thinks it might have happened, you will need to go to hospital and be monitored to ensure you do not have any negative side-effects.

The Patient Information Leaflet should explain which side effects are the most common for the medication you are taking.

Can anything be done to avoid these side-effects?

Having regular injections can be uncomfortable and seem daunting to begin with. However, many people find they get used to the process and feel more comfortable with it over time. If getting injections is making you feel anxious or stressed, speak to your nurse or doctor.

The physical discomfort of regular injections can also be reduced by changing the place you get the injection each time.

Different long-acting injectable medications are given at different intervals. For example, some are given weekly, some are given every 2 weeks, and some are given every 6 months. If you find the injections painful, you might decide to use a medication that allows you to get injections less frequently.

If you experience unpleasant side-effects, speak to your clinician about the following options:

• having smaller amounts of the medication. Your doctor should be able to help you find a dose that gives you as few side-effects as possible.
• using another antipsychotic that has less side-effects.

If you are admitted to hospital under a section of the Mental Health Act, the doctors could make you have a treatment even if you don't want it. This could include a long-acting injectable antipsychotic.

However, your doctor should still discuss this with you and consider your feelings and opinions about your treatment.

If you still don’t want to have a treatment after three months, the hospital are legally required to ask an independent doctor to see you. They will decide if you need to keep taking it or not.

Some people find long-acting injectable antipsychotics helpful. In some cases people decide to make an ‘advanced decision’ to have them if they become unwell. This is where you tell someone or write down what you want to happen if you later become unwell and find it harder to make decisions.

If you miss an injection, you should have another one as soon as you can. If you do not, after a while the medication will stop working and you might become unwell again.

If you are becoming unwell again you might start having the symptoms you had when you were unwell in the past. For example, hearing voices or feeling troubled or distressed.

While you are taking a long-acting injectable antipsychotic, you will usually need to see a health professional every few weeks to get your injection. This would be a great opportunity to talk to them about any concerns you have.

You could also speak to your doctor, nurse or key worker. They might be able to reassure you, or provide a helpful explanation about why you have been prescribed a particular treatment.

They might also be able to discuss alternative treatments with you. If you have any questions about your medication or if you do not understand anything you have read here, please ask the people involved in your care. They will want to help you to make the best decision for you about your treatment.

If you want to stop taking your long-acting injectable antipsychotic, speak to your healthcare professional.

They should help you to understand how this might affect your health, safety and life in general. They will want to help you make a balanced and informed decision and can advise you on whether to stop and how to do this safely.

Antipsychotics are not addictive, but your body does get used to them. Stopping suddenly can make you feel physically and mentally unwell. Because of this, it is best to reduce the dose of the medication slowly by a small amount every few weeks. This will make you less likely to develop withdrawal symptoms while you reduce how much medication you take. It will also help you and your clinician to work out if you are becoming mentally unwell. 

If your symptoms return, or start to get worse while you are reducing the dose or after you have stopped completely, speak to your doctor. They can discuss your continued care and treatment plan with you.

Antipsychotics can make you feel sleepy, so if you are taking them remember:

• Alcohol can make you even more sleepy.
• If you are not fully awake or if you feel the medication is affecting your concentration, don't drive a car or work any machinery.
• Some other medications, such as sleeping pills or hay fever pills might make you feel sleepier than they usually would.

If you are taking a long-acting injectable antipsychotic for schizophrenia, bipolar disorder or psychosis, your GP surgery should invite you to have an annual health check.

The person doing your annual health check will be able to look for any health problems, and help you get the treatment you need to stay well.

This information was produced by the Royal College of Psychiatrists’ Public Engagement Editorial Board (PEEB). It reflects the best available evidence at the time of writing.

Expert author:  Dr Konstantinos Ioannidis
Expert review: The Royal College of Psychiatrists’ Psychopharmacology Committee
Expert by experience: Nick Hunter

Special thanks to Michael Robinson, who kindly agreed for his words to be used as a quote in this resource.

Full references available on request.