This clinical trial looks to see if the medication ondansetron can help treat hallucinations associated with Parkinson’s disease.

What Happens In This Study?

You will either be given a medicine called ondansetron or a placebo (a dummy pill that looks like the medicine but has no active ingredients). Neither you, nor the research team, will know which group you are in.

Can I Join This Study?

To take part in this medical trial, you must meet these 6 requirements:

1. Your Diagnosis: A doctor must have confirmed that you have Parkinson’s disease OR Dementia with Lewy Bodies.
2. Your Age: You are over 18 years old.
3. Your Symptoms: You must be experiencing visual hallucinations due to your Parkinson’s disease OR Dementia with Lewy Bodies. These must have been happening at least once a week for the past month.
4. Your Current Medicine: You must have been taking the same Parkinson’s medication for at least the last 1 month without making any big changes to it.
5. Your Time: You must do your best to attend all your study visits, and follow the rules of the study until it ends.
6. Taking the Medicine: You must be willing and able to swallow the trial medication.

Study Length: 24 weeks (6 months)

Number of appointments: 3 visits, plus check in phone calls

More information on the trial can be on the UCL website.