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Cannabis extract for muscle spasticity


This medicine may make you feel dizzy or sleepy. If this happens, do not drive and do not use tools or machines until you feel better.

When you first start the medicine, carefully follow your doctor's instructions to find the dose that works best for you.

Do not use more than twelve sprayed doses per day or more than one sprayed dose in fifteen minutes.

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About cannabis extract

Type of medicine

Cannabis extract (delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD))

Used for

Muscle spasticity in people with multiple sclerosis (MS)

Also called


Available as

Oral spray (oromucosal)

Nerve fibres in your brain and spinal cord carry tiny electrical messages (impulses) between your brain and muscles allowing you to move. The nerve fibres are protected by a special protein 'coat' known as myelin which helps the electrical impulses travel quickly. In multiple sclerosis (MS) areas of this protective coat become damaged which means the nerve fibres cannot control your muscles properly. This can lead to symptoms such as shaking (tremors) or spasms of some of your muscles.

Some muscles may also shorten (contract) tightly and can then become stiff and harder to use. This is called spasticity. Cannabis extract in the form of Sativex® spray is used to relieve the symptoms of spasticity in people with MS. This can help you to move your muscles more easily and with less pain. Cannabis extract cannot repair the damage to the myelin coat. It works by affecting certain natural chemicals (called neurotransmitters) in your brain which control the nerve impulses to your muscles.

Sativex® is used alongside other medicines, to relieve spasticity when those medicines are no longer as effective. Sativex® can only be prescribed by a doctor who specialises in treating MS symptoms. You will be prescribed an initial trial of this medicine to see if it is right for you.

Sativex® oromucosal spray is a specially prepared medicine that contains ingredients that have been extracted from the cannabis plant. Unlike using or smoking cannabis, Sativex® should not make you feel 'high' when being taken at prescribed doses. Sativex® may make you feel dizzy and drowsy, or give you a feeling like being drunk, especially when you first start taking it. If this does not settle down, or if it becomes troublesome, you may need to reduce your dose and ask your doctor for advice.

Before taking cannabis extract (Sativex®)

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

  • If you are pregnant or trying for a baby.

  • If you are breastfeeding (cannabis extract will be present in your milk and can affect your baby).

  • If you have any problems with your heart or blood vessels.

  • If you have high blood pressure (hypertension).

  • If you have epilepsy.

  • If you, or any member of your immediate family, have experienced mental health problems known as psychosis or schizophrenia.

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

  • If you have ever been dependent on drugs or alcohol.

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

  • If you are taking 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.

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How to take cannabis extract (Sativex®)

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The manufacturer's leaflet will give you more information about using Sativex® spray and a full list of side-effects which you may experience from taking it.

  • Take cannabis extract exactly as your doctor tells you to. When you first start using Sativex® spray, your doctor will ask you to increase your dose gradually over a period of two weeks. This will help you to find the dose that controls your symptoms whilst keeping side-effects to a minimum.

  • During this initial trial period carefully follow the instructions your doctor has given you to find the right dose. After the first few days you will need to increase your dose by one spray each day until you have relief from your symptoms or until you are using 12 sprayed doses per day.

  • Morning doses can be taken any time between waking and midday. Evening doses should be taken any time between 4 pm and bedtime. It is important to leave at least 15 minutes between each spray.

  • Once you have found the daily dose that works for you, carry on using Sativex® spray at this same dose. Your doctor will review your progress and together you can decide whether to continue using cannabis extract.

  • Only use Sativex® spray in your mouth by pointing the nozzle under your tongue or at the inside of your cheek. Try to use it on a different area of your mouth each time so as to avoid any irritation developing.

  • Try not to eat or drink anything immediately before or after your doses.

  • If you forget to take a dose, take it as soon as you remember or when you feel you need it. Do not take two doses together to make up for a missed one.

Getting the most from your treatment

  • Try to keep all your regular appointments with your doctor. This is so your doctor can check on your progress. Your treatment will be reviewed after four weeks of taking cannabis extract and then on a regular basis if you continue.

  • Ask your doctor for advice about drinking alcohol. Your doctor may recommend that you do not drink alcohol while taking cannabis extract because it increases the possibility of side-effects such as feeling dizzy and sleepy.

  • If you are a driver, please be aware that cannabis extract is likely to affect your reactions and ability to drive. It is an offence to drive while your reactions are impaired. Even if your driving ability is not impaired, you are advised to carry with you some evidence that the medicine has been prescribed for you - a repeat prescription form or a patient information leaflet from the pack is generally considered suitable.

  • For some people, if you have been unable to move your muscles for some time they may have become too weak to fully support you. Then, if this medicine helps you move again, you may have difficulty standing or be at risk of falling over. Be aware of this and take care when moving about. Ask your doctor for advice on physiotherapy or exercises to strengthen your muscles.

  • It is not yet known how cannabis extract might affect pregnancies or the developing baby. For this reason you are advised to use reliable contraception during treatment and for three months after stopping.

  • If you are planning a trip abroad, you are advised to carry a letter with you from your doctor to explain that you have been prescribed cannabis extract. This is because cannabis extract is classed as a 'controlled drug' and is subject to certain restrictions.

  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking cannabis extract.

  • If you buy any medicines, check with your doctor or a pharmacist that they are suitable for you to take with cannabis extract.

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Can cannabis extract 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 most common ones associated with cannabis extract. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common cannabis extract side-effects

What can I do if I experience this?

Feeling dizzy or sleepy

This is very common in the first few weeks of treatment but should settle down. If you are affected, do not drive and do not use tools or machines until you feel better

Feeling sick (nausea) or being sick (vomiting)

Eat simple meals (avoid rich or spicy foods). Try using fewer sprays until you feel better

Constipation or diarrhoea

Drink plenty of water and try to eat a well-balanced diet

Dry mouth or changes in your sense of taste

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

Mouth problems such as a burning sensation, pain or mouth ulcers

Make sure you use the spray on a different area of your mouth each time. If any of these become troublesome, let your doctor know

Loss of balance, falling over, feeling drunk

Try to stand up slowly and use something for support. If this becomes troublesome it could be a sign your dose is too high. Try using fewer sprays and speak with your doctor

A change in appetite, lack of energy, feeling weak or generally unwell

If any of these become troublesome, let your doctor know

Cannabis extract works by affecting the chemical messages in your brain. This means there is a risk it could affect your mood, personality or they way you view your surroundings. Stop using cannabis extract and speak with your doctor if you experience any of the following:

  • Difficulty speaking, feeling confused, having trouble concentrating or problems with your memory.

  • Feeling over-excited, losing touch with reality, seeing or hearing things that are not really there (hallucinating), believing ideas that are not true.

  • Feeling that other people are against you, feeling depressed or having thoughts about harming yourself.

If you experience any other symptoms which you think may be due to this medicine, speak with your doctor or pharmacist.

How to store cannabis extract spray (Sativex®)

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

  • Unopened bottles of Sativex® spray should be stored in the fridge.

  • Once opened, store in a cool, dry place, away from direct heat and light, and use within 42 days. On the label, write down the date you opened the bottle to remind you.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

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.

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