Patient leaflet - HALF SINEMET CR 25 MG / 100 MG PROLONGED-RELEASE TABLETS
1 What Half Sinemet CR is and what it is used for
Sinemet CR improves the signs of Parkinson’s disease. Parkinson's disease is a long-term illness where:
- you become slow and unsteady
- your muscles feel stiff
- you may develop shaking or trembling (called ‘tremor’).
If not treated, Parkinson's disease can make it hard for you to continue your normal daily activities.
Half Sinemet CR contains two different medicines called: levodopa and carbidopa.
- levodopa turns into a material called ‘dopamine’ in your brain. The dopamine helps to improve the signs of your Parkinson’s disease.
- carbidopa belongs to a group of medicines called ‘aromatic amino acid decarboxylase inhibitors’. It helps levodopa work more
effectively by slowing the speed at which levodopa is broken down in your body.
2 Before you take Half Sinemet CR
Do not take Half Sinemet CR if:
- you are allergic (hypersensitive) to carbidopa or levodopa or any of the other ingredients of Half Sinemet CR (listed in Section 6)
- you have ever had skin cancer or you have any unusual moles which have not been examined by your doctor
- you are taking certain medicines called ‘MAOIs’ (Monoamine Oxidase Inhibitors) used for depression. You need to stop using these
medicines at least two weeks before you start Half Sinemet CR (see also under ‘Taking other medicines ’ below)
- you have a condition called ‘narrow-angle glaucoma’ that may cause a sudden build up of pressure in the eye
- you have a severe mental disorder
- you are pregnant, might become pregnant, or are breast-feeding.
Do not take Half Sinemet CR if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before taking Half Sinemet CR.
Take special care with Half Sinemet CR
Check with your doctor or pharmacist before taking your medicine if:
- you have a history of fits (convulsions)
- you have had an ulcer in your gut (called ‘duodenal’ or ‘peptic ulcer’) or have vomited blood
- you have had a heart attack, heart beat problems, circulation or breathing problems
- you have had kidney, liver or hormonal problems
- you have had depression or other mental problems
- you have a condition called ‘chronic wide-angle glaucoma’ that may cause a build up of pressure in the eye. You will need to have regular checks on the pressure in your eye
- you sometimes have sudden sleep attacks or sometimes feel very sleepy
- you are due to have surgery.
If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before taking Half Sinemet CR.
Tell your doctor if you or your family/carer notices you are developing addiction-like symptoms leading to craving for large doses of Half Sinemet CR and other medicines used to treat Parkinson’s disease.
Tell your doctor if you or your family/carer notices you are developing urges or cravings to behave in ways that are unusual for you or you cannot resist the impulse, drive or temptation to carry out certain activities that could harm yourself or others. These behaviours are called impulse control disorders and can include addictive gambling, excessive eating or spending, an abnormally high sex drive or an increase in sexual thoughts or feelings. Your doctor may need to review your treatments.
Taking other medicines
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription. This includes herbal medicines. This is because Half Sinemet CR can affect the way some other medicines work. Also some other medicines can affect the way Half Sinemet CR works.
In particular tell your doctor or pharmacist if you are taking any of the following medicines:
- Medicines for Parkinson’s disease containing levodopa:
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– If they are ‘slow release’, you will need to wait 24 hours after your last dose before starting Half Sinemet CR.
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– If they are ‘normal release’, you will need to wait 12 hours after your last dose before starting Half Sinemet CR.
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– Tell the doctor or pharmacist even if you have only taken them in the past.
Medicines for Parkinson’s disease which do not contain levodopa will usually be continued. However, your dose may be changed.
- Medicines for mental problems (including depression), tuberculosis (TB), high blood pressure, muscle spasms, epilepsy or other diseases related to involuntary movements. Your dose may need to be changed.
- Medicines to treat low iron. Your dose may need to be changed.
- Medicines called ‘MAOIs’ (see also ‘Do not take Half Sinemet CR if’).
- Anticholinergic medicines (such as orphenadrine, trihexyphenidyl, benzatropine and procyclidine). Your dose may need to be changed.
- Phenytoin which is used to treat fits (convulsions).
- Papaverine which is used to treat impotence in men.
If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before taking this medicine. Your doctor or pharmacist has a more complete list of medicines to avoid while taking Half Sinemet CR.
Tests while you are taking Half Sinemet CR
This medication can affect some laboratory tests that your doctor may perform on blood or urine samples. Please remind your doctor if you are taking Half Sinemet CR and are having any tests.
Taking Half Sinemet CR with food and drink
Try to avoid taking your tablets with a heavy meal. If your diet contains too much protein (meat, eggs, milk, cheese) Half Sinemet CR may not work as well as it should.
Pregnancy and breast-feeding
Do not take Half Sinemet CR if you are pregnant, might become pregnant or are breast-feeding. Levodopa, one of the substances in Half Sinemet CR, is passed into human milk.
Ask your doctor or pharmacist for advice before taking any medicine, if you are pregnant or breast-feeding.
Driving and using machines
- Half Sinemet CR affects different people in different ways. Some people have side effects which affect their ability to drive or use tools or machines (see Section 4 Possible side effects). Do not drive or use tools or machines if you get these effects.
- Half Sinemet CR can also make you sleepy or cause ‚sudden sleep attacks‘. If this happens to you, you must not drive or use tools or machines. Your doctor will tell you if you can start driving again if these attacks stop.
3 How to take Half Sinemet CR
Always take Half Sinemet CR exactly as your doctor has told you. You should check with your doctor or pharmacist if you are not sure.
Taking this medicine
- Take this medicine by mouth. You must swallow your tablets whole. Do not break, crush or chew the tablets.
- Although your medicine can have an effect after one day, it may take up to seven days to work.
- Take them at regular time intervals according to your doctor's instructions.
- Do not change the times at which you take your tablets or take any other medicines for Parkinson's disease without first consulting your doctor. You should not take Sinemet CR or Half Sinemet CR tablets at intervals of less than 4 hours apart.
- Try to avoid taking your tablets with a heavy meal.
If you have not had levodopa before
The usual starting dose for Half Sinemet CR is one tablet twice a day.
If you have had levodopa before
- your doctor will ask you to stop taking your medicine for Parkinson’s disease for 8 hours before you start taking Half Sinemet CR.
The usual starting dose for Half Sinemet CR is one tablet twice a day. Your doctor may ask you to take Half Sinemet CR to help in determining the correct dose.
A combination of more than one Sinemet or Half Sinemet CR product may be prescribed by your doctor. If you have been given different Sinemet or Half Sinemet CR tablets to take make sure that you are taking the correct one at the right time. Remember: Half Sinemet CR is a lower dose tablet than Sinemet CR.
Children under 18 years of age
Half Sinemet CR is not suitable for children under the age of 18 years.
If you take more Half Sinemet CR than you should
If you take too many tablets see your doctor immediately.
If you forget to take Half Sinemet CR
Do not take a double dose to make up for a forgotten dose.
If you stop taking Half Sinemet CR
Do not stop taking Half Sinemet CR or change your dose without talking to your doctor first. When you stop taking Half Sinemet CR the following can occur: stiff muscles, high temperature (fever) and mental changes.
If you have any further questions on the use of this product, ask your doctor or pharmacist.
4 Possible side effects
Like all medicines, Half Sinemet CR can cause side effects, although not everybody gets them.
Stop taking Half Sinemet CR and see your doctor straight away, if you notice any of the following side effects:
- allergic reaction, the signs may include hives (nettle rash), itching, rash, swelling of your face, lips, tongue or throat. This may cause difficulty in breathing or swallowing
- chest pain
- uneven (irregular) heart beat or palpitations
- dizziness on standing-up quickly
- bleeding from your gut which may be seen as blood in your faeces or darkened faeces (gastro-intestinal bleeding)
- blood problems, the signs may include pale skin (pallor), tiredness, fever, sore throat or mild bruising and prolonged bleeding after injury
- stiff muscles, high fever
- mental changes including delusions, hallucinations and depression
- fits (convulsions).
- abnormal movements such as twitching or spasms (which may or may not be like your Parkinson's symptoms)
- nausea.
- fainting, anorexia, high blood pressure
- inflammation of the veins, being sick (vomiting), diarrhoea, discoloration of urine, sweat or saliva
- on-off phenomenon, characteristic of some people with long-standing Parkinson’s disease. This is when you can have unpredictable changes from being mobile – ‚on‘ – to a sudden inability to move – ‚off‘. ‚Off‘ to ‚on‘ can occur just as suddenly
- dizziness; sleepiness (including excessive drowsiness or sudden sleep onset episodes), pins and needles
- dream abnormalities, confusion, feeling agitated, shortness of breath, hair loss.
You may experience the following side effects:
- Craving for large doses of Half Sinemet CR in excess of that required to control motor symptoms, known as dopamine dysregulation syndrome. Some patients experience severe abnormal involuntary movements (dyskinesias), mood swings or other side effects after taking large doses of Half Sinemet CR.
- inability to resist the impulse to perform an action that could be harmful, which may include:
o strong impulse to gamble excessively despite serious personal or family consequences
o altered or increased sexual interest and behaviour of significant concern to you or to others, for example, an increased sexual drive o uncontrollable excessive shopping or spending
o binge eating (eating large amounts of food in a short time period) or compulsive eating (eating more food than normal and more than is needed to satisfy your hunger)
Tell your doctor if you experience any of these behaviours; he/she will discuss ways of managing or reducing the symptoms.
Side effects that have been reported with medicines containing levodopa.
These may be experienced when taking Half Sinemet CR.
Nervous system:
- loss of control over the voluntary movements of everyday life
- numbness, increased hand tremor, muscle twitching, muscle cramp, irregular movement of jaw muscles resulting in difficulty opening the mouth
- difficulty sleeping, feeling anxious or high, falling over and abnormal walking patterns
- headache
Eyes:
- drooping eyelid and dilated pupil
- changes in vision, irregular movement of the eye
Digestive system:
- indigestion, dry mouth, bitter taste
- swelling of the salivary glands, difficulty swallowing, grinding of the teeth
- hiccups, abdominal pain and distress, constipation, wind
- burning sensation of the tongue
Sexual:
- persistent abnormal erection of the penis
Urinary:
- difficulty passing urine or incontinence (inability to control urine flow)
Skin:
- changed patches of pigmented skin, including, irritated or irregular moles, or moles in which you have noticed changes (melanoma) General:
- weight gain or loss,
- swelling in the limbs
- flushing, hot flushes, increased sweating
- feeling weak, faint or tired
- hoarseness, general feeling of being unwell
- increased energy or activity, unusual breathing pattern
5 How to store Half Sinemet CR
Keep out of the sight and reach of children.
Do not store above 30°C. Store in the original package in order to protect from light.
Do not take the tablets after the expiry date which is stated on the carton and blister labels after ‘Exp’. The expiry date refers to the last day of that month.
If the tablet becomes discoloured or show any signs of deterioration, seek the advice of your pharmacist.
Remember if your doctor tells you to stop taking this medicine, return any unused medicine to your pharmacist for safe disposal. Only keep this medicine if your doctor tells you to.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.
6 Further information
What Half Sinemet CR contains
Each prolonged-release tablet contains carbidopa (equivalent to 25mg of anhydrous carbidopa) and 100mg levodopa.
The other ingredients are hydroxypropylcellulose, magnesium stearate, poly (vinyl acetate-crotonic acid) copolymer, red iron oxide (E172).
What Half Sinemet CR looks like and contents of the pack
Half Sinemet CR is a pink-coloured, oval, biconvex compressed tablet engraved ‚601‘ on one side and plain on the other side.
Half Sinemet CR are available as blister packs of 30 tablets.
Manufactured by: Merck Sharp & Dohme B.V., Waarderweg 39, 2031 BN, Haarlem, The Netherlands.
Procured from within the EU and repackaged by the Product Licence holder: B&S Healthcare, Unit 4, Bradfield Road, Ruislip,
Middlesex, HA4 0NU, UK.
Half Sinemet ® CR 25mg/100mg Prolonged-release tablets; PL 18799/1603
Leaflet date: 22.12.2017 | POM |
SINEMET is a registered trademark of Merck & Co., Inc
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