Risperidone Intramuscular injection is used to treat schizophrenia (an illness that causes changes in perception, thoughts and behaviour). It helps to relieve symptoms common in schizophrenia, such as distorted thinking and emotional instability.
Risperidone Intramuscular injection is also used on its own or together with other medicines for the treatment of a dysfunctional mood condition called bipolar disorder.
Risperidone Intramuscular injection is to be injected into the buttock muscles.
Your doctor or nurse will administer the injection for you. This injection will be made only ONCE every 2 weeks.
You may need to use Risperidone Intramuscular injection for some time before the full benefits can be felt. Do not be discouraged if you do not feel better soon after the injection has been given. It may take about 3 weeks for this injection to take effect. This is because the medicine is being released slowly from the site of injection. Over the long-term, this slow-release injection helps to give better control of your condition.
It is important that you continue with the injections even when you feel well. Do not stop using Risperidone Intramuscular injection unless your doctor has decided to do so. If this medicine is stopped suddenly, you may feel unwell or your condition may worsen. When your doctor decides that you do not need Risperidone Intramuscular injection anymore, he will usually reduce your dose slowly.
Ensure that you keep all appointments with your doctor so that you do not miss any doses. Your doctor also needs to regularly monitor your response to Risperidone.
If you miss an appointment or miss an injection, alert your doctor or nurse. A replacement appointment or injection should be given as soon as possible.
DO NOT double a dose under any circumstances.
Risperidone is not suitable for patients with dementia-related psychosis.
Inform your doctor if you have:
- fits or a history of fits (epilepsy)
- Parkinson's disease
- liver or kidney disease
- heart disease, including heart rhythm problems
- high blood pressure
- blood disorders
- glaucoma (high pressure in the eyes)
- breast cancer or tumours dependent on a hormone called prolactin
- risk factors for stroke
- suicidal thoughts
Let your doctor know if you are pregnant or breastfeeding.
Risperidone Intramuscular injection may affect how your body adjusts to temperature changes. Avoid exposure to very cold or very hot environments.
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly. He may need to do routine blood tests such as fasting blood glucose and complete blood count while you are being treated with Risperidone Intramuscular injection.
Risperidone may cause dizziness, drowsiness, and blurred vision. If affected, do not drive or take part in any activity in which you need to be alert.
You may feel dizzy when getting up from a sitting or lying down position, especially if this is your first Risperidone Intramuscular injection, or if your doctor is still adjusting your dose. This dizziness is normal and should improve gradually as you get used to the medicine. It will help if you get up slowly from a sitting or lying down position.
Some common side effects with Risperidone Intramuscular injection include difficulty sleeping, headache, tiredness, weakness, agitation, anxiety, mood changes, constipation, increased appetite, weight gain, loss of bladder control, common cold, blocked nose, nausea, vomiting and stomach discomfort. There may also be some discomfort or pain at the injection site.
Other side effects may need immediate medical help. Alert your doctor immediately if you experience any of the following:
- fast or irregular heartbeat
- chest pain
- muscle stiffness, unexplained high fever
- uncontrolled muscle movements of your body or face, such as sticking out of the tongue, smacking of the lips
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor and pharmacist if you are taking any of these medicines:
- medicine for cold or allergy e.g. antihistamines
- medicines for depression e.g. fluoxetine, paroxetine
- medicines for mood disorder e.g. clozapine
- fits (epilepsy) medicines e.g. phenytoin, carbamazepine
- medicines for Parkinson's disease e.g. levodopa
- medicines that lower blood pressure
- diuretics (water pills) e.g. furosemide
- medicines for irregular heart rhythm e.g. quinine, disopyramide, procainamide, amiodarone
- certain antibiotics e.g. rifampicin
This list does not include all medicines that may interact with Risperidone.
Always notify your doctor or pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
Avoid alcohol. Alcohol will worsen the dizziness and drowsiness caused by Risperidone Intramuscular injection.
Store in a cool, dry place away from the reach of children.
Risperidone Intramuscular injection should be stored in the refrigerator between 2-8 degrees Celsius. Always keep the vial in the original carton.
Medicines must not be used past the expiry date.