Terazosin and Early Cardiac Changes in Pre-Motor Parkinson's Disease

Condition: REM sleep behavior disorder, Parkinson’s disease


Key Inclusion Criteria:

  • 25-85 years old
  • Diagnosis of idiopathic REM sleep behavior disorder (iRBD), established either as “definite RBD” or “probable RBD”
  • At least one of the following: hyposmia, functional constipation, color vision abnormality, or symptoms of depression

Key Exclusion Criteria:

  • Secondary Parkinsonism
  • Concurrent dementia
  • Concurrent severe depression

Study Name

The Effect of Alpha 1-Adrenergic Receptor Antagonist Therapy on Cardiac and Striatal Transporter Uptake in Pre-Motor and Symptomatic Parkinson’s Disease (IRB no. 00000540)


This study focuses on individuals who have REM sleep behavior disorder (RBD) and is designed to evaluate the investigational use of a drug called terazosin. RBD is a sleep disorder causing people to ‘act out’ their dreams. A high percentage of individuals with idiopathic RBD (iRBD) are known to develop conditions affecting the neurons in the brain, such as Parkinson’s disease (PD).

Early changes of PD are associated with symptoms including loss of smell, constipation, anxiety and depression. In addition, early heart and brain imaging abnormalities can be seen using specialized imaging techniques such as 123I-MIBG myocardial scintigraphy (MIBG). In this study, researchers aim to learn about the effect of terazosin on imaging abnormalities, specifically MIBG, that are considered early markers of predisposition to PD and are frequently found in people with RBD.

Terazosin is approved by the U.S. Food and Drug Administration (FDA) for use in various conditions, but it is not approved in patients with RBD with symptoms and MIBG imaging abnormalities suggesting a predisposition to PD.

Principal Investigator