Levodopa and carbidopa

Commonly called Sinemet

Levodopa and carbidopa is used to treat the symptoms of Parkinson's disease. Find out how to take it safely and possible side effects. Levodopa and carbidopa is also called Sinemet.

Type of medicine Also called
  • Dopaminergic medicine
  • Belongs to a group of medicines to treat Parkinson's disease
  • Sinemet®
  • Sinemet CR®

What is levodopa + carbidopa?

Levodopa + carbidopa in combination is used to treat the symptoms of Parkinson's disease, or Parkinson-like symptoms such as tremor, shakiness, stiffness, and difficulty moving. Levodopa changes into dopamine, a chemical in the brain that helps control movement. Carbidopa prevents levodopa changing to dopamine in the bloodstream. This means that more levodopa can enter the brain, and helps to lessen some of the side effects such as nausea and vomiting. 


In New Zealand levodopa + carbidopa combination is available in different forms and strengths with different amounts of carbidopa and levodopa in each tablet. This combination is available in 2 forms, tablets and modified- release tablets. Check with your pharmacist which form you are taking. Your doctor may prescribe the tablets and the modified release tablets, to be taken at different times of the day.

Tablets: Sinemet 25/100; Sinemet 25/250; Kinson 25/100
Modified-release tablets: Sinemet CR

  • The dose of levodopa + carbidopa combination is different for different people. 
  • You will be started on a low dose and depending on your response, your doctor will increase your dose to control your symptoms.
  • Always take your levodopa + carbidopa exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much levodopa + carbidopa to take, how often to take it, and any special instructions.

How to take levodopa + carbidopa

  • Tablets: swallow the tablet whole, with a glass of water.
  • Modified release tablet (has CR after the name): swallow the tablet whole, with a glass of water. Do not crush or chew the tablets because all the medicine will be released at once, increasing your chance of side effects.
  • Timing: Take your tablet at the same times each day. You can take levodopa + carbidopa combination with or without food, but it is best NOT to take doses immediately after a large meal. Avoid taking levodopa + carbidopa with a high-protein meal because it may decrease the effects of this medication. Be consistent and take your dose at about the same time in relation to food. Talk to your doctor before you make changes to your diet.
  • Missed dose: If you do miss a dose then just take your next dose when it is due. Do not take double the dose.  
  • Keep taking levodopa + carbidopa regularly. Do not stop taking levodopa + carbidopa or lower the dose, without checking with your doctor. Your doctor may want you to gradually reduce the amount of levodopa + carbidopa you are using before stopping completely. This may help reduce the possibility of withdrawal symptoms such as muscle stiffness, fever and mental changes.

Side effects

Like all medicines, levodopa + carbidopa can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Changes in the colour of your urine, sweat or saliva — it may turn red, brown or black 
  • This is harmless and is nothing to worry about
  • Falling asleep suddenly during daily activities (such as talking on the phone, or driving)
  • This sleep effect can occur without any feelings of drowsiness beforehand, and can happen anytime during treatment with this medication, including up to 1 year after starting the medication
  • Tell your doctor
  • Do not drive or use tools until you know how this medicine affects you and until these have stopped happening
  • Avoid drinking alcohol
  • Feeling sick (nausea)
  • Vomiting
  • Loss of appetite(not wanting to eat)
  • Changes in taste
  • These are quite common when you first start taking levodopa + carbidopa
  • Try taking your doses after a light meal
  • Tell your doctor if troublesome
  • Feeling dizzy when you stand up
  • Be careful when getting up from either lying down or sitting to avoid falls
  • Tell your doctor
  • Changes in your mood such as feeling anxious, nervous or agitated, or feeling excited or depressed
  • Tell your doctor 
  • Uncontrollable jerky movements, where you switch suddenly from being able to move to being immobile
  • Tell your doctor immediately or ring HealthLine 0800 611 116 


Levodopa + carbidopa interacts with a number of important medications, herbal and food supplements, so check with your doctor or pharmacist.

Learn more

The following links provide further information on levodopa + carbidopa.

Medsafe Consumer Information Sheets:


Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 23 Dec 2015