Long-term effects of terazosin on Parkinson's disease symptoms

The Effect of Alpha1- Adrenergic Receptor Antagonist Therapy on Cardiac and Striatal Transporter Uptake in Pre-Motor and Symptomatic Parkinson's Disease: a Follow Up Study

Phase 2 Interventional Cedars-Sinai Medical Center · NCT05109364

This study is testing if terazosin can help people at risk for Parkinson's disease by looking at changes in their brain scans and symptoms over time.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment15 (estimated)
Ages50 Years to 85 Years
SexAll
SponsorCedars-Sinai Medical Center Academic / other
Locations1 site (Los Angeles, California)
Trial IDNCT05109364 on ClinicalTrials.gov

What this trial studies

This study investigates the long-term effects of terazosin, a selective post-synaptic a1-adrenergic blocker, on individuals with pre-motor Parkinson's disease risks and abnormal imaging results. Participants will undergo serial imaging with 123I-FP DAT-SPECT to assess changes in dopamine transporter uptake, while also evaluating motor and non-motor symptoms through validated clinical scales and cardiac autonomic function tests. The study aims to correlate imaging changes with symptom severity and estimate the rate of clinical conversion from REM Sleep Behavior Disorder (RBD) to Parkinson's disease.

Who should consider this trial

Good fit: Ideal candidates include individuals with pre-motor Parkinson's disease risks such as RBD and specific abnormal imaging findings.

Not a fit: Patients with secondary Parkinsonism, severe cognitive impairment, or significant comorbidities may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into a new therapeutic approach for managing symptoms and potentially delaying the onset of Parkinson's disease.

How similar studies have performed: While there have been studies on adrenergic antagonists in Parkinson's disease, the specific use of terazosin in this context is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Enrolled in the study "The Effect of alpha1- adrenergic receptor antagonist Therapy on Cardiac and Striatal Transporter Uptake in Pre-Motor and Symptomatic Parkinson's Disease" (STUDY #000540)
* Capacity to give informed consent

Exclusion Criteria:

* Secondary Parkinsonism, including tardive
* Concurrent dementia defined by a score lower than 22 on The Montreal Cognitive Assessment (MoCA)
* Concurrent severe depression defined by a Beck Depression Inventory-Fast Screen (BDI fast screen) score greater than 13
* Comorbidities related to sympathetic nervous system (SNS) hyperactivity
* Heart failure (LVEF \<45%)
* Recent myocardial revascularization (\<12 weeks)
* Hypertension (systolic blood pressure SBP\>150mmHg (millimeters of mercury) or diastolic blood pressure DBP\>100mmHg)
* Chronic Atrial fibrillation
* Concurrent Use of Beta-adrenergic antagonist
* Diabetes mellitus
* Chronic Obstructive Pulmonary Disease (COPD)
* Untreated Sever Sleep Apnea; Apnea-Hypopnea Index (AHI) \> 30/h.
* Severely reduced kidney function (Glomerular Filtration Rate\<30ml/min)
* Contraindications to the use of terazosin
* Recent myocardial infarction (\<48 h)
* Ongoing angina pectoris
* Cardiogenic shock or prolonged hypotension
* Breast-feeding
* Current use of phosphodiesterase type 5 inhibitors: sildenafil (ViagraTM), tadalafil (CialisTM), or vardenafil (LevitraTM)
* History of priapism (persistent and painful erection)
* Neurogenic orthostatic hypotension defined as symptomatic decrease in BP \> 20mmHg systolic or \> 10mmHg diastolic and HR increase \< 20bpm on supine to sitting or standing.
* Blood pressure less than 110 mm Hg systolic at screening or baseline visit
* Use of investigational drugs within 30 days before screening
* For female participant, pregnancy, or plans for child-bearing during study period
* Allergy/hypersensitivity to iodine or study medication

Where this trial is running

Los Angeles, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Symptomatic Parkinson DiseaseREM Sleep Behavior DisorderPre-motor Parkinson's DiseaseParkinson's diseaseREM sleep behavior disorderAutonomic dysfunctionNeurodegenerationTerazosin
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.