4.8 What are the main issues related to Parkinson’s medication?

Wearing off

In 'wearing off', symptoms may re-emerge when medication is due to be taken. This usually occurs near the end of a medication dose, or near the beginning of the next dose. It indicates that medication is not working as well, and if the these symptoms are causing an impact on a client’s activities, then their medication should be reviewed.


Some people with Parkinson’s might also experience what’s known as the ‘on/off’ effect. When a person's symptoms are well controlled, this is known as the 'on' period, which means that medication is working well. When symptoms return, this is known as the 'off' period.

This might mean that a person who is out for a walk would suddenly be unable to continue walking, or when seated would feel unable to get up to answer the door.

'Off' periods usually come on gradually, but occasionally can be more sudden. When they come on suddenly, some people have compared this 'on/off' effect to that of a light switch being turned on and off.

Side effects

We cannot list all of the side effects of Parkinson’s drugs here. But some of the drugs used to treat Parkinson’s can cause problems with movement, behaviour, thinking and memory. It may not be obvious that these problems are caused by medication.

Symptoms may include confusion and hallucinations (seeing, hearing, feeling or tasting things that aren’t there). The person you are caring for may not report them as problems, because they seem very real to them. It is important to have a medication review from their specialist or Parkinson’s nurse if you suspect that they have these side effects.


Dyskinesia is when people with Parkinson’s experience muscle movements that they can’t control. They may be caused by a combination of the condition and Parkinson’s medication. It is most common in people who have been taking levodopa for many years.

The involuntary movements can be jerking, twitches or spasms, and can affect any part of the body. The strength of dyskinesias can vary from mild to severe. To reduce dyskinesia, the only option is to reduce their medication dose. But if you cut the dose of levodopa, a person’s Parkinson’s symptoms may not be so well controlled and they may experience more wearing off. Some people may choose to live with the dyskinesia rather than compromise their ability to take part in their usual activities.

People with dyskinesia use up vast amounts of energy and calories because of their constant movement. It is vitally important to look carefully at their diet to ensure that they are not at risk of becoming malnourished.

Actions to take

  • Maintain a food and fluid diary to monitor the person’s intake.
  • Monitor their weight.
  • Talk to your manager if you have concerns about a person’s excessive weight loss or poor appetite. A dietitian may be able to advise.
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Impulsive and compulsive behaviour

This is a side effect that affects some people taking dopamine agonists. However, it can affect people taking other Parkinson’s drugs too, including levodopa.

Impulsive behaviour is when a person can’t resist the temptation to carry out certain activities. These are often activities that give an immediate reward or pleasure, such as gambling, eating or shopping, punding (continually handling and sorting objects) or an increase in sexual thoughts, feelings and actions (hypersexuality). Often, people may demonstrate more than one of these behaviours.

This behaviour may lead to harmful social, financial or legal consequences. The person may carry out a particular activity without giving any thought to the future or to long-term consequences. For example, someone who has the impulse to shop might buy a new item of clothing, even if they can’t really afford it.

Compulsive behaviour is when a person has an overwhelming drive to act in a certain way, often repetitively, to reduce the worry or tension that they get from their urge. Some people continue to act in this way, even if they no longer get any pleasure or reward from the activity.

In most cases, this behaviour is out of character for the particular person. Impulsive and compulsive behaviour can have a devastating effect on people with Parkinson’s and those around them.

The impulsive and compulsive behaviour film [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] discusses this topic in detail. Although it is aimed at Parkinson’s nurses it will help your understanding of this topic.

Actions to take

  • Make sure that people with Parkinson’s and their families know about this potential side effect of Parkinson’s medication. Also, make sure that they understand that these side effects can be managed effectively. You may encourage them to read our information sheet. Make sure any behavioural changes you are concerned about are reported.
  • Listen to family members, friends and carers when they’re worried about someone with Parkinson’s, and make sure the person’s specialist or Parkinson’s nurse is aware of these concerns.
  • Inappropriate sexual behaviour could be caused by hypersexuality. Make sure your manager is aware of your concerns. The person’s specialist or Parkinson’s nurse should be contacted.
  • A client’s sexual behaviour may be environmental. They may require some privacy to masturbate to relieve sexual frustration. Staff should speak to their manager about what is the best course of action.
  • Tell your manager if you think they’re taking too much of their medicine on purpose – this could be a sign of drug-related compulsive behaviour.

4.7 Getting medication on time

4.9 A case study