Effect of Terazosin on ATP Levels in People With Amyotrophic Lateral Sclerosis (TZ-ALS)

September 2, 2026 updated by: Andrea Swenson, University of Iowa

A Pilot Study of the Effect of Terazosin on ATP Levels in People With Amyotrophic Lateral Sclerosis

This will be a single center, randomized, double-blind, placebo-controlled pilot study to assess the safety and tolerability of terazosin (TZ) at a dose of 5 milligrams (mg) per os (PO) daily for patients with amyotrophic lateral sclerosis (ALS). The primary outcome of this study is to determine whether TZ increases adenosine triphosphate (ATP) levels in ALS. The investigators will measure adverse outcomes, safety, and tolerability of taking TZ. Procedures include blood draws, spirometry, fluorodeoxyglucose-positron emission tomography (FDG-PET) scans, questionnaires, and physical examinations. TZ will be titrated up to 5 mg PO daily. This is a pilot study and is not powered to assess efficacy of this medication. The investigators' hope is that this study will guide future studies of this (and similar) medications for the disease modification of ALS. This study also aims to learn more about how patients produce and use energy and if TZ can help to reverse energy deficits that appear in ALS.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Iowa
      • Iowa City, Iowa, United States, 52242
        • Recruiting
        • University of Iowa Health Care
        • Contact:
        • Principal Investigator:
          • Andrea Swenson, MD
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

INCLUSION CRITERIA

  • Ages 18 - 80 years old
  • Diagnosed with ALS based on Gold Coast Criteria
  • ALS symptom onset within 36 months at enrollment
  • Slow vital capacity (SVC) greater than or equal to 60%
  • Riluzole use-Never taken or taking a stable dose for at least 4 weeks prior to screening visit or will refrain from starting for the duration of the study
  • Edaravone use-Never taken or completed at least one cycle (typically 14 days) prior to screening visit or will refrain from starting for the duration of the study
  • Must have the ability to swallow pills at the time of the screening visit, and in the principle investigator's opinion, have the ability to swallow pills for the duration of the study
  • Willing to use highly effective contraception for the duration of the trial treatment and for a duration of 80 days after the last dose.

EXCLUSION CRITERIA

  • Orthostatic hypotension at screening is defined as decrease in BP > 20 mmHg systolic or > 10 mmHg diastolic and HR increase <20 bpm on transition from supine to sitting or from sitting to standing
  • Known allergy or previous adverse reaction to terazosin or related compound
  • Current use of terazosin or concurrent use of doxazosin, alfuzosin, prazosin, or tamsulosin at the time of screening visit or within the 3 months prior to baseline visit
  • Pregnancy or breastfeeding women
  • Taking therapeutic anticoagulant medication (i.e. warfarin, DOAC's, full dose Lovenox or heparin)
  • Liver function blood tests (ALT or AST) more than twice the upper limit of normal
  • Hemoglobin < 11.0 g/dL
  • Traumatic brain injury or post-traumatic stress disorder
  • Presence of a confounding acute or unstable medical, psychiatric, or orthopedic condition
  • Noncompliant or sporadic use of medications that modulate the central nervous system
  • Uncontrolled major depression or bipolar affective disorder, or other mental health disorders that are, in the opinion of the PI, sufficiently severe to increase risk of experiencing an Adverse Drug Reaction (ADR)
  • Current suicidal ideation as measured by question 2 of the Columbia-Suicide Severity Rating Scale (C-SSRS)
  • Participants with insufficient decisional capacity to provide written informed consent determined by the primary investigator.
  • Noncompliant or sporadic use of antihypertensive medications
  • Unable to lie supine and still for 60 minutes for the duration of the study
  • Currently taking part in another clinical trial with an investigational medicinal product or having taken part in one in the three months prior to screening visit
  • Current diagnosis of diabetes (type 1 or type 2) or healthcare professional-recommended treatment (medication, exercise or diet) of diabetes mellitus
  • Screening visit glucose >140 mg/dl

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: Placebo
Drug: Placebo
Placebo matching terazosin tablets
Experimental: Terazosin
Drug: Terazosine
Titrating up to 5 mg PO at bedtime. Trial participants will take terazosin for 12 weeks.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in ATP levels
Time Frame: Baseline and 12 weeks
Mean percent change from baseline to 12 weeks in whole-blood ATP and brain glycolytic rate using FDG-PET imaging
Baseline and 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Iowa

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Andrea Swenson, MD, University of Iowa

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 12, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 31, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 31, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 4, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 202408197

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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