HeadMeds gives young people in the United Kingdom general information about medication. HeadMeds does not give you medical advice. Please talk to your Doctor or anyone else who is supporting you about your own situation because everyone is different. Please read more important details about our site.

Waitingroom original


Return to Risperidone overview
  1. Use and Action
  2. Warnings and side effects
  3. Sex, drink, weight and everything else
Taking fluoxetine risperidone and sertraline listing
Taking Fluoxetine, Risperidone and Sertraline
I was grumpy when I came off the medication but my weight went back to normal

Headmeds fills the medicines information gaps for young people - things you might want to know about meds like will it affect my sex life? Can I still study?  Can I drink?
Headmeds does not give medical advice so this is just general information.
Each medicine has a balance of good and bad effects, and each person gets their own individual effects.
You might want to know just one thing about your medicine, but on each page we have given you the ‘safety headlines’. Please read them as they are important.
We have included lots of information about each medicine - but if you want all the details, please look at the patient information leaflet - which is inside every pack. These leaflets are also at www.medicines.org.uk - where there will be the most up-to-date information. Please be aware that the leaflets will only refer to the licensed use for your medicine. The leaflet will not mention any off label use - this includes off label conditions and also off label age groups.

Safety headlines

  • If you have taken more risperidone than it said on the label, you must see a doctor quickly - even if you do not feel any different.
  • Risperidone can sometimes cause serious side-effects. Tell your doctor immediately if you experience unusual movements (mainly of the face or tongue). Go to hospital immediately if you think you may have developed a blood clot (symptoms are usually swelling, pain and redness in the leg); a clot may travel through blood vessels to the lungs causing chest pain and difficulty breathing. Also go to hospital if you develop a combination of fever, faster breathing, sweating, muscle stiffness or drowsiness; and tell them that you are taking risperidone.
  • Very rarely risperidone can cause severe allergic reactions - go to hospital if you have difficulty breathing or swelling of your face or throat.
  • In rare cases, risperidone can cause a long-lasting and painful erection in men (called priapism). If this happens you will need to be treated in hospital.
  • Risperidone is not addictive, however stopping it suddenly can cause problems such as difficulty sleeping, feeling or being sick, sweating, and uncontrollable muscle movements. See you doctor if you want to stop, or if you are having these effects.
  • You might feel sleepy in the first few days after taking risperidone – do not drive a car, ride a bike or operate machines until you see how this affects you.
  • If you are pregnant, or thinking of becoming pregnant, please read the pregnancy section (see “Sex, drink, weight and everything else”) because risperidone may affect the developing baby.

Basic details

Risperidone can be used to help the symptoms of a number of conditions including:

  • Psychosis
  • Schizophrenia
  • Bipolar disorder

It can also be used to help other medicines as an add-on for:

  • ADHD 
  • Autism spectrum disorder 
  • Obsessive Compulsive Disorder (OCD)
  • Depression
  • Aggression in behaviour (conduct) disorders
  • Tics and Tourette’s syndrome

How does risperidone work?

There is a naturally occurring chemical messenger ('neurotransmitter') in the brain called dopamine. Dopamine is the chemical messenger in the brain mainly involved with thinking, emotions, behaviour and perception. In some illnesses there may be too much dopamine and this causes some of the symptoms of the illness. The main effect of risperidone is to block the effects of dopamine in the brain, resulting in a reduction of the symptoms. Risperidone also has effects on other neurotransmitters in the brain e.g. serotonin, and its beneficial effects may be related to this as well.

You should take risperidone as agreed with your doctor

  • You will get most benefit from your risperidone if you take it regularly.
  • Make sure that you know your dose. If it is not written on the label, check it with your pharmacist or doctor.
  • Risperidone is usually taken once or twice a day. You will start with a low dose that increases slowly to a dose that is effective for you. This may take several days or weeks.
  • It doesn’t matter what time you take it each day - choose a time that you can always remember and get into a routine. This could be a mealtime, or when you brush your teeth.
  • Risperidone can be taken with or without food.
  • For the normal coated tablets, swallow them whole with a drink of water - if you chew it, it tastes bitter. You can break them into two pieces at the line on the tablet if you have trouble swallowing them as one piece.
  • For the orodispersible (‘melt in your mouth’) tablets, put it on your tongue and let it dissolve there and then swallow it (you can wash down with water if needed).
  • You can dilute the oral solution with any other non-alcoholic drink if it makes it nicer to take, apart from a cup of tea or a glass of cola (chemistry geek note: apparently the tannin chemical in tea and cola stops the risperidone from absorbing properly into your body).
  • If you agree to have the long-acting injection (LAI), a doctor or nurse will inject this into a muscle in your arm or bottom every two weeks. The good thing about this is that you don’t have to remember to take your medicine every day. It is slowly working in your body all the time between injections.
  • The injection should switch between the left side (arm or buttock) and the right side (arm or buttock) so that it’s not given in the same place all the time.

What should I do if I forget to take a dose of risperidone?

What to do if you miss a dose of the tablets or liquid:

  • If you remember later during the day, take it as soon as possible.
  • If you forget to take it by your next dose, just take the next dose at the correct time. Do not try to catch up on missed doses.
  • Do not double dose.

What to do if you miss an injection:

  • If you miss your appointment for your injection, contact your doctor straight away to make another appointment. 
  • It is very important to have the injection every 2 weeks. What might happen? 
  • If you forget to take your tablets for a few days, or you miss an injection, you may start getting your old symptoms back. You should talk to your doctor about this.

You must go to A&E if you take too much

What to do if you take too much:

  • If you have taken more risperidone than it said on the label, you must get help quickly - even if you do not feel any different.
  • Go to A&E. Take your medicine with you, to show to the doctors. Tell them how much you have taken.
  • Get a friend or family member to go with you, if you can, just in case you feel ill on the way

You might get any of the following signs:

  • Feeling sleepy or tired
  • unusual body movements you can’t control
  • problems standing and walking
  • feeling dizzy (due to low blood pressure)
  • uneven heartbeat
  • fits (seizures)

It can take 4-6 weeks for risperidone to have full effect, but some people get good effects right from the first week

  • Many people say that it takes 4-6 weeks for risperidone to show its full effect.
  • Some studies now, however, show a good effect for some people within the first week.
  • 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 2-3 weeks, your doctor may increase the dose or change the medicine.
  • Your doctor will start with a low dose that increases slowly to a dose that is effective for you. This may take several days or weeks.
  • If you are starting on the long-acting injection, it takes 3 weeks for the injection to start releasing the risperidone.
  • This means you will need some other antipsychotic cover. This could be risperidone tablets or your previous antipsychotic.
  • The injection provides 2 weeks of constant release of risperidone so injections are given every 2 weeks. The 3 week delay in the injection starting to release risperidone only matters when you first start treatment. Think of the injection having a very long fuse wire. 
  • If you were already on some other tablets, you will need to continue with them for those first few weeks on the injection.*
  • If you were not on other tablets, the doctor will probably give you some risperidone tablets until the injection starts to work.*
  • If you were on another depot or long-acting injection, you may have one dose of each, very close together.*

*Don’t worry – as explained above you will not overdose whilst you take both types for those first few weeks. 

Many people take risperidone for a few years

You and your doctor should talk about how long you need to take risperidone.

  • You will not get the full effect for several weeks.
  • If you take risperidone for bipolar or schizophrenia you should think about taking it for a few years - otherwise your old symptoms can come back.

People taking it for conduct disorders usually only take it for 6 weeks 

  • Young people taking risperidone for conduct disorders will usually only take it for 6 weeks.

Reference sources

Search www.medicines.org.uk to find patient information leaflets and prescribing information on risperidone. Plain tablets, orodispersible tablets, liquid and injection (Consta) are listed separately. The SmPC lists all the inactive ingredients in the product so you can check against any allergies. If you are still unsure about this then speak to your pharmacist.

  • British National Formulary (BNF) and British National Formulary for children. Download the BNF/BNFC app (blue background) on to your mobile device. No longer available for public access via the web 
  • Taylor D, Barnes T, Young A. Maudsley Prescribing Guidelines in Psychiatry, 13th edition. Oxford: John Wiley & Sons, May 2018. ISBN: 978-1-119-44260-8
  • Royal Pharmaceutical Society. Medicines Ethics and Practice (42nd edition). London: RPS, 2018. Standards for pharmacists to work to. It is not a free publication
  • World Anti Doping Agency WADA Prohibited List https://www.wada-ama.org/en/resources/science-medicine/prohibited-list-documents 
  • Choiceandmedication; an independent source of information on many mental health conditions and their medicines with easy to read fact sheets www.choiceandmedication.org Personal subscriptions to download the app available for £1 per month (with proportionate discounts for longer periods) but your local mental health Trust may subscribe and provide information sheets for free.
  • Best Use of Medicines in Pregnancy (BUMPS). Information sheets on drugs in pregnancy http://www.medicinesinpregnancy.org/ 
  • Drugs and Lactation Database (LactMed). Information on drugs in breastfeeding https://toxnet.nlm.nih.gov/newtoxnet/lactmed.htm
  • NICE CG178 Psychosis and Schizophrenia in adults. Feb 2014 (last updated Mar 2014). (https://www.nice.org.uk/guidance/cg178)
  • NICE CG155 Psychosis and schizophrenia in children and young people. Jan 2013 (last updated Oct 2016). (https://www.nice.org.uk/guidance/cg155)