A drug used to treat enlarged prostates could slow down Parkinson's disease progression and improve movement symptoms, according to new research.

The study published in the Journal of Clinical Investigation suggests that the prostate drug, terazosin, can slow the loss of brain cells in various models of Parkinson’s, including in mice. This also led to increased dopamine levels. 

The reason for this protection was thought to be because the drug may provide brain cells with more energy by boosting an enzyme called PGK1.

In addition to studying the potential of terazosin in the lab, the researchers also looked at existing data from those taking the drug. By comparing data from 150,000 people treated for an enlarged prostate - where half were on drugs such as terazosin and half were on alternative medication that didn’t affect PGK1 - they found that those on terazosin were less likely to develop Parkinson’s. 

Existing data from people with Parkinson’s who have been treated for an enlarged prostate was also used in the study. And the researchers found that those treated with terazosin seemed to have less severe symptoms and slower progression of their Parkinson’s. 

New treatments for Parkinson's disease?

Terazosin is a drug that has already been shown to be safe and approved as a treatment and the results from this study highlight the potential for this drug to be investigated as a repurposed drug for Parkinson’s. Repurposing can allow new treatments to become available much more easily, quickly and cheaply. 

The prostate drug now needs to be tested in clinical trials to see if it alters the progression of Parkinson’s, clinical trials are currently being planned in the US

Professor David Dexter, Deputy Director of Research at Parkinson's UK, said: "These exciting results show that terazosin may have hidden potential for slowing the progression of Parkinson's, something that is desperately needed to help people live well for longer.

"While it is early days, both animal models and studies looking at people who already take the drug show promising signs that need to be investigated further."