The Effect Of Lisinopril On Polycythemia

August 19, 2026 updated by: Michael J. Joyner, M.D., Mayo Clinic
The purpose of this study is to evaluate the effect of the (angiotensin-converting enzyme) ACE inhibitor lisinopril on hemoglobin, hematocrit, and erythropoietin levels in patients with secondary polycythemia due to high-oxygen-affinity hemoglobin variants, oxygen-sensing pathway mutations, or other unexplained and potentially irreversible forms of erythrocytosis. This study aims to determine whether ACE inhibition can effectively reduce excessive erythrocytosis by modulating erythropoietin production.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Demonstrating that ACE inhibitor therapy with lisinopril lowers hemoglobin, hematocrit, and erythropoietin levels could introduce a novel therapeutic approach for the management of secondary polycythemia due to high-oxygen-affinity hemoglobin variants, oxygen-sensing pathway mutations, or other unexplained and potentially irreversible forms of erythrocytosis, potentially reducing reliance on repeated phlebotomies and lowering thrombotic risk.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Phase 4

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 Locations

    • Minnesota
      • Rochester, Minnesota, United States, 55902
      • Rochester, Minnesota, United States, 55902
        • Recruiting
        • St. Mary's Hospital
        • Contact:
          • Nancy Meyer
          • Phone Number: 507-255-0913
        • Principal Investigator:
          • Michael Joyner, MD

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Hemoglobin in Men: >16.5 g/dL (10.3 mmol/L).
  • Hemoglobin in Women >16.0 g/dL (10.0 mmol/L).
  • BMI 18-40 kg/m2.

Exclusion Criteria:

  • Positive JAK2 gene linked to Polycythemia Vera.
  • Current smoker or previous heavy smoker (>15 pack years) who quit less than 12 months prior to enrollment.
  • Resting SpO₂ ≤ 94% on room air.
  • Current or recent (within the past 6 months) use of testosterone or androgen supplementation.
  • Any confounding respiratory or renal disease, including diagnosed or suspected sleep apnea, or stage 3 and up of chronic kidney disease.
  • Any confounding hematologic disease that may alter hemoglobin level.
  • Currently treated with ACE inhibitors.
  • Currently treated with potassium-sparing diuretics.
  • Currently on SGLT2 or use within 4 weeks prior to screening.
  • Baseline systolic blood pressure ≤90 mmHg.
  • Baseline systolic blood pressure >160 mmHg or diastolic blood pressure >100 mmHg.
  • Occupational exposure associated with chronically elevated COHb (auto repair, etc.).
  • History of anaphylaxis or angioedema.
  • Pregnant or breastfeeding.

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: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Lisinopril
Patients diagnosed with polycythemia will be treated with Lisinopril, 2.5 mg tablets

Subjects will be treated with Lisinopril in three phases:

Phase 1:

Baseline-3 weeks: 2.5 mg dose

Phase 2:

Weeks 4 - 7: 5 mg dose (2 x 2.5mg tablets)

Phase 3:

Weeks 8-12: 10 mg dose (4 x 2.5 mg tablets)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in hemoglobin
Time Frame: Baseline (dose 0), study day 3 (dose 2.5), study day 5 (dose 5.0), and study day 7 (dose 10.0)
Hemoglobin measures the amount of a protein in red blood cells via blood sample and is reported in grams per deciliter (g/DL) Hemoglobin (Hb) concentration exceeding 16 g/dL in women and 16.5 g/dL in men is considered abnormal.
Baseline (dose 0), study day 3 (dose 2.5), study day 5 (dose 5.0), and study day 7 (dose 10.0)
Change in hematocrit
Time Frame: Baseline (dose 0), study day 3 (dose 2.5), study day 5 (dose 5.0), and study day 7 (dose 10.0)
Hematocrit (Hct) is measured by determining the percentage of red blood cells (RBCs) in a blood sample. Hematocrit (Hct) ≥ 48% in women and ≥49% in men is considered elevated.
Baseline (dose 0), study day 3 (dose 2.5), study day 5 (dose 5.0), and study day 7 (dose 10.0)
Change in erythropoietin
Time Frame: Baseline (dose 0), study day 3 (dose 2.5), study day 5 (dose 5.0), and study day 7 (dose 10.0)
Erythropoietin is measured via blood test to detect hormone levels, and is reported in milliunits per milliliter (mU/mL). A normal reference range is generally 4 to 26 mU/mL)
Baseline (dose 0), study day 3 (dose 2.5), study day 5 (dose 5.0), and study day 7 (dose 10.0)

Collaborators and Investigators

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

Sponsor

Investigators

  • Principal Investigator: Michael Joyner, MD, Mayo Clinic

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)

July 1, 2026

Primary Completion (Estimated)

July 1, 2028

Study Completion (Estimated)

July 1, 2029

Study Registration Dates

First Submitted

May 13, 2026

First Submitted That Met QC Criteria

May 13, 2026

First Posted (Actual)

May 18, 2026

Study Record Updates

Last Update Posted (Actual)

August 21, 2026

Last Update Submitted That Met QC Criteria

August 19, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 26-003687

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

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.