Levodopa is one of the main drugs used to treat Parkinson's symptoms. It can be used at all stages of the condition.
Levodopa is a chemical building-block that your body converts into dopamine. It replaces the dopamine that is lost in Parkinson's.
How does levodopa work?
Dopamine is a chemical messenger made in the brain. The symptoms of Parkinson's appear when dopamine levels become too low.
This is because many of the cells in your brain that produce dopamine have died or are dying.
Unfortunately, taking dopamine as a drug doesn’t help as it can’t cross into your brain where it’s needed. Doctors can get around this by using levodopa.
Levodopa is a chemical building block that your body converts into dopamine. Levodopa already occurs naturally in your body and taking it as a drug treatment boosts the supply, meaning the nerve cells can make more dopamine.
When is levodopa used?
Levodopa can be used at all stages of Parkinson’s. However, it can have side effects (see below) that build up as symptoms progress. This includes the drugs wearing off so you have times when you're stiff and slow, and involuntary movements (dyskinesia).
When should you start taking levodopa?
There is no particular time to start taking levodopa that is right for everyone. You and your specialist or Parkinson’s nurse will agree what is the best choice for you.
Treatment will usually start with a low dose. This is gradually increased until your symptoms are under control.
What types of levodopa are there?
Levodopa is always combined with benserazide or carbidopa to help more levodopa to get into the brain and make it work better.
- Unbranded (capsules)
- Madopar (capsules, dispersible tablets)
- Madopar CR (controlled release capsules)
- Unbranded (tablets)
- Caramet CR (controlled released tablets)
- Duodopa (intestinal gel)
- Sinemet (tablets)
- Sinemet Plus (tablets)
- Sinemet CR (controlled release tablets)
- Half Sinemet CR (controlled release tablets)
- Lecado (prolonged release tablets)
Co-careldopa plus entacapone
- Stalevo/Sastravi (tablets)
What are controlled release drugs?
Controlled or prolonged release drugs let the levodopa enter your body slowly instead of all at once. They are particularly helpful if they are taken before going to bed to reduce stiffness during the night.
Controlled release can also help to reduce one of the side effects of levodopa - involuntary movements.
What are dispersible tablets?
Dispersible tablets can be mixed with water to make a drink. It takes effect more quickly than capsules because it doesn’t need to be broken down in your stomach to release the active ingredient. It can also be used if you have trouble swallowing tablets or capsules.
If you are prescribed non-dispersible tablets or capsules, these should not be crushed or put into water.
What is intestinal gel (Duodopa)?
A type of levodopa called Duodopa is pumped as a gel through a tube that is surgically inserted into the intestine. The gel can help reduce two side effects - involuntary movements and your drugs wearing off. It may also help to control your symptoms at night.
This option is only suitable for a very small number of people whose symptoms can’t be controlled with the more common forms of treatment.
Levodopa and protein
For some people with Parkinson’s, protein (which is found mainly in meat, fish, eggs, cheese, beans and pulses) seems to interfere with how well levodopa is absorbed by the body. Because of this, you may benefit from taking your medication 30 - 60 minutes before you eat a meal.
However, levodopa can sometimes make people feel sick. Eating a low protein snack (such as crackers) when you take your dose may help to reduce this side effect.
You may also benefit from a protein redistribution diet, where you take most of your daily protein in the evening. This can help the levodopa treatment to be more effective in the daytime, when you are likely to need it more. Find out more about diet and medication.
Parkinson’s is unique to each individual, so if you have any questions about your medication, your specialist will always be best placed to provide tailored advice.
Protein is essential for a healthy diet so you should also talk to your specialist before you make any changes to what you eat.
Benefits of levodopa
Levodopa is an effective treatment for Parkinson’s symptoms.
You may experience a big improvement in your symptoms when taking it, especially with stiffness and slowness of movement.
Risks and side effects of levodopa
Levodopa becomes less effective over time. Other side effects will also build up as your symptoms progress.
The patient information leaflet that comes with your drugs will tell you the full range of side effects that you may experience. Some of the possible side effects include:
With long-term use of levodopa you may experience wearing off. This is when your drugs wear off before you can take the next dose so you have times when you're stiff and slow.
Involuntary movements (dyskinesia)
With long-term use of levodopa you may experience involuntary movements (dyskinesia).
Impulsive and compulsive behaviour
A small number of people taking levodopa have problems with impulsive and compulsive behaviour. This can also be called impulse control disorder.
Withdrawal syndrome with levodopa
Research has shown that withdrawal symptoms can happen when someone stops taking levodopa very suddenly, perhaps because they are experiencing impulsive and compulsive behaviour. It can lead to symptoms including depression, anxiety or pain. Any withdrawal from Parkinson’s drugs needs to be done gradually, under the supervision of a health professional, to avoid the risk of developing this syndrome.
Other side effects
Other common side effects include:
- nausea and vomiting
- low blood pressure (hypotension)
- loss of appetite
- psychological problems
- hallucinations (seeing, hearing, feeling and smelling things that aren’t there)
- sleep problems
Domperidone (Motilium) is the anti-sickness drug of choice to prevent and treat nausea and vomiting caused by levodopa.
Domperidone can cause heart rhythm problems (arrhythmia) in some people over the age of 60. If you are prescribed this medication, your specialist, Parkinson’s nurse or pharmacist should talk to you about how to recognise signs of irregular heart rhythms.
Other anti-sickness drugs that are generally considered useful include cyclizine (Valoid) and 5-HT3 receptor antagonists like ondansetron.
Find out more about the side effects of Parkinson's drugs.