Risperidone

What is risperidone?

Risperidone is an antipsychotic used to treat various mental health conditions by helping to balance chemicals in the brain[1]. 

What is risperidone used to treat?

Risperidone may be prescribed for[1]:

• Schizophrenia – to manage symptoms such as hallucinations and delusions

• Bipolar disorder – to treat manic episodes 

• Irritability associated with autism – in children and adolescents 

• Aggression and behavioural problems – in people with dementia or Alzheimer’s disease (short-term use only) 

How does risperidone work?

Risperidone works by adjusting levels of dopamine and serotonin, two brain chemicals involved in mood and behaviour. This helps to reduce symptoms like psychosis, mood swings, and aggression[1]. 

Who can take risperidone?

This medicine can be suitable for both adults and children over 5 in certain cases, but it’s not right for everyone[1]. 

Speak to your doctor if you have[1]: 

• Heart problems 

• Liver or kidney disease 

• Parkinson’s disease 

• Diabetes 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is the usual dose of risperidone?

Standard risperidone tablets come in strengths of 0.25mg, 0.5mg, 1mg, 2mg, 3mg, 4mg and 6mg. Tablets that melt in your mouth (orodispersible) come in strengths of 0.5mg, 1mg, 2mg, 3mg and 4mg. Risperidone liquid contains 1mg per 1ml[1]. 

Your dose will depend on your age, the condition being treated, and how your body responds to the medicine[1]:

• Treatment usually starts with a low dose, gradually increased

• Common doses range from 0.5mg to 6mg per day 

• Can be taken once or twice daily 

• Available in tablets, liquid, and long-acting injections

How do you take risperidone?

For best results, take risperidone consistently and carefully as follows[1]:

• Take it at the same time each day, with or without food 

• If using the liquid, use the provided syringe or spoon to measure accurately 

• Do not stop taking risperidone suddenly unless advised by your doctor 

Can I stop taking risperidone?

Do not stop this medicine on your own – it should always be tapered gradually under medical supervision to avoid withdrawal symptoms or a return of symptoms[1]. 

What if I take too much risperidone?

Taking too much risperidone can be dangerous and may cause[1]: 

• Drowsiness 

• Fast heartbeat 

• Muscle stiffness or abnormal movements 

• Seizures 

Call 999 or go to A&E immediately if you or someone else may have taken too much. 

What if I forget a dose of risperidone?

If you forget to take risperidone[1]:

• Take the missed dose as soon as you remember 

• If it’s nearly time for the next dose, skip the missed one 

• Do not take two doses at once 

What drugs can’t I take with risperidone?

Risperidone can interact with other drugs, so caution is needed. Speak to your doctor or pharmacist before combining it with[1]: 

• Other antipsychotic medicines 

• Blood pressure tablets – may cause a further drop in blood pressure 

• Drugs that affect heart rhythm (like some antibiotics or antidepressants) 

• Alcohol – can increase drowsiness and side effects 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

Side effects of risperidone

Like all medicines, risperidone can cause side effects. Some are mild, while others may need medical attention[1]. 

The most common side effects include: 

• Drowsiness or dizziness 

• Weight gain 

• Increased appetite 

• Headaches 

• Anxiety or restlessness 

The rare, but more serious side effects include[1]: 

• Muscle stiffness or tremors 

• Involuntary movements (especially in the face or tongue) 

• Signs of high blood sugar (e.g. extreme thirst or frequent urination) 

• Seizures 

• Allergic reaction – rash, swelling, or difficulty breathing 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include: 

• Difficulty breathing

• Tightness in throat and chest

• Swelling of the tongue or throat

• Feeling faint or dizzy

• Blue/grey skin or lips

• Loss of consciousness

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about risperidone

Is risperidone addictive? 
No, but stopping it suddenly can cause withdrawal symptoms or a return of your condition[1]. 

Can I drink alcohol while taking risperidone? 
It's best to avoid alcohol as it may increase drowsiness or other side effects[1]. 

Will risperidone affect my weight? 
Risperidone can make you feel a bit hungrier than normal, so may lead to weight increase. Try to maintain a balanced diet and keep portion sizes the same[1]. 

How long does risperidone take to work? 
Some symptoms may improve in a few days, but it may take several weeks for full benefit[1]. 

Can I drive or operate machinery while taking risperidone? 
Avoid these activities if you feel drowsy or dizzy. This can often happen when you first start taking the drug[1]. 

For the official NHS guide for risperidone, visit their website.