Risperidone

It can take four to six weeks for risperidone to have its full effect, but some people get good effects right from 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 two to three weeks, your doctor may increase the dose or change the medicine.

Your doctor will start with a low dose, which they will increase 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 three 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 a constant release of risperidone over two weeks, so injections are given every two weeks. The three-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 while you take both types for those first few weeks. 

Risperidone use has been linked to high blood sugar and diabetes in some young people. This could be linked to putting on weight.

Watch out for any early signs of diabetes: wanting to drink a lot, going for a wee a lot, feeling less hungry and feeling weak.

If you already have diabetes, taking risperidone may affect your blood sugar levels. Talk to your doctor and check your blood glucose levels regularly if this applies to you. You may have to increase the medication you use for your diabetes.

A side effect of risperidone may be either weight loss or weight gain.

Weight gain is more common than weight loss.

It is very difficult to know how it will affect each person who takes it. If you start to have problems with your weight while taking risperidone, talk to your doctor or pharmacist about this.

Your doctor should measure your weight regularly when you are taking risperidone.

Most of the weight gain is in the first six to 12 months, and then it levels out.

As you grow you will gain weight naturally, but anything more than that should be watched.

Good practice for doctors suggests this routine for checking the weight of people who start taking antipsychotic medicines like risperidone:

• get your weight noted before you start
• get your weight checked every week for the first six weeks and then again after three months
• get your weight and waist measurement checked at least every six months

You could take these measurements yourself and keep a chart to show your doctor.

If you put on weight, there are other antipsychotic medicines you can try which are less likely to make you put on weight.

Look at ways to try and lose extra unwanted weight.

You may want to let your family and friends know you are taking risperidone so they can support you and help you look out for side effects.

For guidance on this, check out our page on getting support with your medication.

You can feel sleepy in the first few days of taking risperidone. This should get better after the first week or two.

If you feel like a zombie, and you’ve been taking it for more than a month, you should go back to the doctor and see what else you can do.

With risperidone, some people find it hard to get to sleep. If this happens, you can change the time that you take your risperidone each day (if you are taking tablets or liquid). Take it earlier in the day and see if this makes it easier to get to sleep.

If you are on the long-acting injection, talk to your doctor if your sleep is disturbed.

Alcohol

You can continue to drink alcohol in moderation while taking risperidone. You might find having the two together makes you very sleepy, so during the first few days it might be best to stop drinking alcohol until you see how the medicine affects you.

If you want to drink alcohol, remember that you might be sleepy and make sure you can get home safely.

Street drugs

Some street drugs can increase levels of dopamine in the brain (e.g. cocaine and ecstasy). As antipsychotics block the effects of dopamine, the 'high' from street drugs may not be as 'high' as before. You may therefore be tempted to increase the dose of your street drug to make up for it, but this could be dangerous.

Cannabis and other drugs may have their own side effects on your mental health, like anxiety or psychosis. For more information, have a look at our drugs and alcohol page.

Some street drugs can make you feel sleepy and this could be made worse with risperidone.

There are many other street drugs, but we don’t know what effect taking them with risperidone will have.

Risperidone can produce a false positive test for LSD on a urine drug screen.

Talk to your doctor about this if it is a problem for you.

Risperidone can interact with some other medicines and drugs

Check with your doctor or pharmacist whether risperidone is OK for you to take if you are on any other medicines.

If you have any further questions about this, you should speak to your doctor or pharmacist.

Always talk to the doctor if you are taking other medicines. Tell the pharmacist you are taking risperidone if you buy medicines (including things you put on your skin) for common illnesses.

The ordinary tablets may not be suitable for you if you have problems eating some sugars or dairy (milk-based) foods, as they contain lactose. Some brands of the 2mg strength tablets may also have a colour called ‘Sunset Yellow’ (also known as E110) which causes an allergic reaction in some people.

The orodispersible ('melt in your mouth') tablets may contain aspartame, which can be a problem for people who have a condition called phenylketonuria.

Let your pharmacist know if you have any food allergies or intolerances, and always check with them if you’re concerned about any of the ingredients in your medication.

Taking risperidone may make you feel tired or dizzy, and may affect your eyesight when you start taking it.

This could affect you if you drive a car, ride a bike, or do anything else that needs a lot of focus. It might be best to stop doing these things for the first few days, until you know how it affects you.

Don't worry - most people drive as normal while taking risperidone.

You must tell The DVLA (Driver and Vehicle Licensing Agency) if you have bipolar disorder, schizophrenia, schizoaffective disorder or other mental health conditions that could affect your driving.

You can be fined up to £1,000 if you do not tell The DVLA about a medical condition that affects your driving.

You may be prosecuted if you are involved in an accident as a result.

Pregnancy

When deciding whether to take risperidone during pregnancy it is important to weigh up how necessary risperidone is to your health against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are.

Remaining well is particularly important during pregnancy and while caring for a baby. Treatment with risperidone in pregnancy may be the best option for both mother and baby.

As with other antipsychotics, taking risperidone may cause your folate levels to become low and a prescribed supplement dose of 5mg daily should be taken.

There is information on over 400 mums who took risperidone and there does not seem to be an increased risk of malformations, miscarriage or diabetes during pregnancy.

Post-natal

If you have taken risperidone close to delivery your baby may have some side effects or such as being irritable, crying or problems feeding and sleeping. These are usually mild and go away in a few days without treatment.

Breastfeeding

Risperidone is passed to the baby through breast milk in small amounts. This could help with any discontinuation symptoms.

You should discuss the risks and benefits of breastfeeding with your midwife or doctor.

Remember that it is important for you to remain well while you are bonding with and looking after your baby. For this reason, it may be best to take medicine for your mental health when breastfeeding.

Make sure that your doctor, nurse, or health visitor checks your baby for any side effects.

If your baby was premature or has health problems, then you will need to be extra careful about taking medicines while breastfeeding. It may be best not to breastfeed if this is the case, but you should discuss this with your doctor or midwife.

Sex

Risperidone can have side effects that affect your sex life, including:

• painful erections, or problems getting an erection (getting hard) and ejaculating (coming)
• periods may become irregular or stop due to raised prolactin levels. Talk to your doctor and they will be able to do a simple blood test to check if the risperidone is the cause
• some bleeding from the vagina, and difficulty reaching orgasm the same way as before
• some breast growth and milk flow, regardless of gender
• decrease in libido (sex drive)

These effects should pass after the first couple of weeks. If they do not, and this is a problem for you, go back to the doctor and see what else you could try.

Fertility

While taking risperidone it might be more difficult for you to fall pregnant, but this effect is not permanent.

Risperidone can increase the level of a natural hormone called prolactin in the body.

This hormone is produced in high levels to produce milk in breastfeeding mothers and provides some natural contraception.

Prolactin is produced at low levels in men.

This means it may be more difficult to get pregnant if your prolactin levels rise. Do NOT rely on this as an alternative to good contraception.

Talk to your doctor about this if you want to get pregnant, and see below for more information about taking risperidone during pregnancy.

Risperidone is not a banned substance in sport.

Taking risperidone may make you feel tired and dizzy, and affect your eyesight. This could be dangerous in some sports like cycling or driving. It might be best to stop such sports for the first few days, until you know how it affects you.

Don't worry - most people play sports as normal while taking risperidone.

Try not to take risperidone for the first time just before your exams.

Taking risperidone may make you feel tired or make it hard to fall asleep at night. It can also give you headaches or affect your eyesight.

You should talk to your doctor about any future exams if you are starting risperidone.

You might decide together to delay starting it until you have done them.

If they are more than a month away, however, you might find that it is better to start risperidone to improve your motivation to study.

Don't worry - most people take exams as normal while taking risperidone.

Psychosis and schizophrenia themselves can also affect concentration.