Sinemet Plus improves the signs of Parkinson’s disease.

Why have I been prescribed Sinemet Plus?

Sinemet plus improves the signs of Parkinson’s disease.

How does it work?

Sinemet Plus 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.

When and how do I take it?

  • Take this medicine by mouth.
  • 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.
  • Try to avoid taking your tablets with a heavy meal. If your diet contains too much protein (meat, eggs, milk, cheese) Sinemet may not work as well as it should.

What’s the dose?

If you have not had levodopa before. The usual starting dose is:

  • for Sinemet Plus 25 mg/100 mg Tablets: one tablet three times a day.
  • for Sinemet 10 mg/100 mg Tablets or Sinemet 12.5 mg/50 mg Tablets: one tablet three or four times a day.
  • for Sinemet 25 mg/250 mg Tablets: half of one tablet once or twice a day.

If you have had levodopa before

  • your doctor will ask you to stop taking your medicine for Parkinson’s disease before you start taking Sinemet.

The usual starting dose is:

  • for Sinemet Plus 25 mg/100 mg Tablets and Sinemet 25 mg/250 mg Tablets: one tablet three or four times a day.
  • for Sinemet 10 mg/100 mg Tablets and Sinemet 12.5 mg/50 mg Tablets it will depend on what you were taking before.

Could it interact with other tablets?

Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription. This is because Sinemet can affect the way some other medicines work. Also some other medicines can affect the way Sinemet works.

In particular tell your doctor or pharmacist if you are taking any of the following medicines:

Medicines for Parkinson’s disease containing levodopa:

  • If they are ‘slow release’, you will need to wait 24 hours after your last dose before starting Sinemet.
  • If they are ‘normal release’, you will need to wait 12 hours after your last dose before starting Sinemet.
  • 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 to treat low iron. Your dose may need to be changed.
  • Medicines called ‘MAOIs’ used for treating depression.
  • 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 Intervene pharmacist before taking this medicine. Your doctor or pharmacist has a more complete list of medicines to avoid while taking Sinemet.

What are the possible risks or side-effects?

Like all medicines, Sinemet can cause side effects, although not everybody gets them. Stop taking Sinemet 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).

The most common side effects are

  • abnormal movements such as twitching or spasms (which may or may not be like your Parkinson's symptoms)
  • nausea.

Other side effects include:

  • 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, increased sexual drive, shortness of breath, hair loss
  • an excessive desire to gamble.

Can I drink alcohol while taking it?

  • There are no known interactions between alcohol and Sinemet.
  • Always ask your pharmacist/doctor however as other tablets you are taking may have a bearing on whether you can drink alcohol or not.

What if I’m pregnant/breastfeeding?

  • Do not take Sinemet if you are pregnant, might become pregnant or are breast-feeding.
  • Levodopa, one of the substances in Sinemet, is passed into human milk.


If you have any more questions please ask your Pharmacist.

Remember to keep all medicines out of reach of children
Please Note:
We have made every effort to ensure that the content of this information sheet is correct at time of publish, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.



Health Reference: Parkinson's disease