Skip to main content

Fluphenazine long-acting injection


Clinical author's note Michael Stewart 05/12/2022: Modecate® injections were discontinued in the United Kingdom in November 2020. At the time of review there are no licensed injection products containing fluphenazine available in the UK. Fluphenazine injections may still be available in other countries or as special order products. This medicine leaflet is based on medical information available in the UK at the time of writing and is left here for reference purposes. Please also refer to the manufacturer's information supplied with your medicine.

Fluphenazine long-acting injection will be given to you by your clinic doctor or nurse every 2-5 weeks.

If you miss an appointment for an injection, make another appointment as soon as possible.

If you either start or stop smoking whilst you are being treated with fluphenazine, tell your doctor. Your dose may need to be adjusted.

Continue reading below

About fluphenazine long-acting injection

Type of medicine

An antipsychotic injection

Used for

Maintenance of symptom control in adults with schizophrenia and other similar mental health problems

Also called

Fluphenazine decanoate; Modecate® (discontinued)

Available as

Long-acting 'depot' injection

Fluphenazine belongs to a group of medicines called antipsychotics. You will have been prescribed it to maintain symptom control of schizophrenia.

Schizophrenia is a mental health condition that causes disordered ideas, beliefs and experiences. Symptoms of schizophrenia include hearing, seeing, or sensing things that are not real, having mistaken beliefs, feeling unusually suspicious, and becoming withdrawn. Fluphenazine is used to relieve the symptoms of schizophrenia and other similar mental health problems. It works on the balance of chemical substances in your brain.

Long-acting, or 'depot', injections are used once your symptoms have been eased by taking tablets. The injection slowly releases fluphenazine into your body and is given every 2-5 weeks. The main advantage of a depot injection is that you do not have to remember to take tablets every day.

Before having fluphenazine long-acting injection

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start having fluphenazine injections, it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you know you have a heart condition or blood vessel disease (such as any thickening of the arteries in your head).

  • If you have any problems with the way your liver works, or if you have any problems with the way your kidneys work.

  • If you have prostate problems.

  • If you have a blood disorder.

  • If you have any problems with your breathing.

  • If you have any of the following: epilepsy, depression, Parkinson's disease, raised pressure in your eye (glaucoma), thyroid problems, or a condition which causes muscle weakness, called myasthenia gravis.

  • If you have ever had yellowing of your skin or the whites of your eyes (jaundice).

  • If you have a tumour on your adrenal gland (a condition called phaeochromocytoma).

  • If you have had an allergic reaction to a medicine.

  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

Continue reading below

How fluphenazine long-acting injection is given

  • Before you start this treatment, ask to read the manufacturer's printed information leaflet from inside the pack. The leaflet will give you more information about fluphenazine, and it will also provide you with a full list of the side-effects which you could experience.

  • Fluphenazine long-acting injection will be given to you by a doctor or nurse. If you haven't received an injection like fluphenazine before, a small dose is usually given as a test 4-7 days before you have a full dose. This is to see how well you tolerate the injection. The injection is given into a muscle in your bottom (buttocks).

  • You may be asked to continue taking your currently prescribed tablets for a short while after you have had your first injection. This is because it can take a few weeks before you feel the full effect from the injection.

  • Treatment with fluphenazine is usually long-term so that your symptoms don't return.

Getting the most from your treatment

  • Your treatment will require careful monitoring to make sure that you get the best possible benefit from fluphenazine. Keep your regular doctor's appointments so that you get your injections on time, and your progress can be checked. If you miss an appointment for an injection, contact your doctor to arrange for another appointment as soon as possible.

  • Medicines similar to fluphenazine can cause people to become more sensitive to sunlight than normal. It is recommended that you avoid strong sunlight and sunbeds, and use a sun cream with a high sun protection factor even on bright but cloudy days.

  • If you drink alcohol, ask your doctor for advice about drinking while you are on fluphenazine. Alcohol can increase the chance that you experience side-effects and may not be advisable for you.

  • Smoking can interfere with the way your body handles fluphenazine. If you either start smoking or quit smoking whilst you are having fluphenazine, please make sure that you tell your doctor. It is probable that your dose will need to be adjusted.

  • If you have diabetes you may need to check your blood glucose more frequently, as fluphenazine can affect the levels of sugar in your blood. Your doctor will advise you about this.

  • If you are having any dental treatment or an operation, tell the person carrying out the treatment that you have had a fluphenazine injection. This is important because it may interfere with the anaesthetic or painkillers you receive.

  • If you buy or take any 'over-the-counter' medicines, check with a pharmacist that they are suitable for you to take with fluphenazine.

Continue reading below

Can fluphenazine long-acting injection cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with fluphenazine. The best place to find a full list of the side-effects which can be associated with your injection, is from the manufacturer's printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer's information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.

Fluphenazine side-effects

What can I do if I experience this?

Pain at the site of the injection

This should not last long. If the area becomes red, swollen or 'lumpy', let your doctor know

Feeling sleepy or dizzy, blurred vision

Do not drive and do not use tools or machines while affected

Dry mouth

Try chewing sugar-free gum or sucking sugar-free sweets

Unusual or uncontrollable muscle movements, feeling shaky

Speak with your doctor about these

Feeling restless, movement problems

Speak with your doctor


Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, speak with your doctor

Changes in weight, stuffy nose, difficulty sleeping, feeling agitated or confused, sexual problems, breast changes, menstrual problems, fast heartbeats, poor judgement or reduced mental ability, stomach upset, constipation, and difficulty passing urine

Discuss these with your doctor if any become troublesome

Important: if you experience symptoms such as muscle stiffness, a very high temperature, feeling confused or sweaty, a fast heartbeat, and urinary incontinence, you should contact your doctor immediately. These can be signs of a rare but serious condition known as neuroleptic malignant syndrome.

If you experience any other symptoms which you think may be due to the injection, speak with your doctor or pharmacist for further advice.

How to store fluphenazine long-acting injection

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

If you suspect that you have had an overdose of this medicine, contact the accident and emergency department of your local hospital for advice.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

symptom checker

Feeling unwell?

Assess your symptoms online for free