ClinicalTrials.gg
Active, not recruitingNCT04173949Updated Mar 13, 2025

Explorative Study for Treating Persistent Developmental Stuttering With Ramipril

A Phase 3 interventional study of Ramipril 2.5 MG in Persistent Developmental Stuttering, sponsored by HaEmek Medical Center, Israel. Active, not recruiting at 2 sites in Israel. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-03-13.

Sponsored by HaEmek Medical Center, Israel · Phase 3, Interventional, and Treatment

From the registry’s dates

  • Primary completion was expected by Dec 2025, 10 months ago, but the record still lists the study as active, not recruiting.
Phase
Phase 3
Study type
Interventional
Enrollment
10
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

Persistent developmental stuttering (PDS) is diagnosed when developmental stuttering persists beyond adolescence. Most stutterers experience vast improvement in stuttering during childhood and it generally disappears within five years. A minority of stutterers continue stuttering over age 18, often accompanied by social and personal difficulties.

Following a report of a 75 year old woman, with severe Persistent developmental stuttering , who experienced significant improvement in her stuttering since treated by Ramipril for hypertension, we scrutinized the literature, and discovered that there is a physiological basis for this surprising reaction. Ace inhibitors, such as Ramipril, might in fact be successful for treating Persistent developmental stuttering .

In theory, it seems that ACE inhibitors, such as Ramipril could improve stuttering by reducing striatum dopamine levels.

  1. Stuttering is associated with high striatum dopamine levels
  2. Angiotensin receptors are present in the striatum
  3. Angiotensin causes elevated striatum dopamine levels
  4. ACE inhibitors penetrate the blood brain barrier and reduce brain angiotensin II levels.

Methods The study will begin as a pilot study in which 10 stuttering patients will be recruited for 12 weeks on open label Ramipril 1.25mg/d.

If there is improvement in at least 2 of the stuttering patients, we will continue to the main study.

Efficacy Evaluation:

  1. The MINI Neuropsychiatric interview will be used to rule out major neuropsychiatric conditions
  2. Stuttering evaluation

    1. Stuttering Severity instrument Version 4 (SSI-4) (Riley 2009)
    2. SLD :Percentage of stuttered syllables (Yairi 2015)
    3. The Subjective Screening of Stuttering (SSS)
    4. Speech Situation Checklist (Brutten 1975,1981)
  3. Leibowitz Social Anxiety Scale (Leibowitz 1987)

The efficacy evaluation will be performed by speech therapists. All evaluations will be will be recorded on video

Safety evaluation:

  1. Blood pressure: The average of three consecutive measures. Blood pressure will be measure in both arms on the first meeting, and thereafter on the arm with the highest measurements.
  2. Orthostatic hypotension will be defined as a drop of 20mmHg systolic or 10mmHg diastolic, one and three minutes after standing from sitting position.
  3. Creatinine clearance will be calculated by the MDRD method (Levy 2006) GFR, in mL/min per 1.73 m2 = 186.3 x SCr (exp[-1.154]) x Age (exp[-0.203]) x (0.742 if female) x (1.21 if black)
02

Conditions studied

  • Persistent Developmental Stuttering

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03

In context

Stuttering

74 studies on the registry are indexed under Stuttering; 23 are open to participants now.

This study's enrollment of 10 is below the median of 44 across 57 interventional studies indexed under Stuttering.

Browse Stuttering studies →

Lead sponsor

HaEmek Medical Center, Israel is the lead sponsor of 237 studies on the registry; 11 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Eligibility criteria

Inclusion Criteria:

Inclusion Criteria:

  • Age 18 or above
  • Developmental stuttering of 10 points severity at least (SSI-4)
  • Agree not to have any speech or emotional therapy during the trial.

Exclusion Criteria:

  • Systolic blood pressure \< 110mmHg
  • Estimated \< 50ml/min
  • Baseline potassium > 5meq/ml
  • Any sign of psychopathology by the MINI international neuropsychiatric interview
  • Any psychotropic medications or substances in the past month
  • History of angioedema or cough with any ACE inhibitor
  • Aliskerin use in diabetes patients
  • Current medication include ACE inhibitors or ARBS
  • Pregnancy, or pregnancy plans during the study
  • Less than 3% stuttered syllables
  • Subjects with cluttering-stuttering when the cluttering is prominent
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Creatinine clearance (CrCl)

How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.

05

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
10 participants (actual)

Study arms

  • Experimental
    Ramipril 2.5 MG

    Ramipril 2.5 MG orall, daily.

    Drug: Ramipril 2.5 MG

Interventions

06

What researchers measure

Primary outcomes

  1. changed in stuttered syllables

    The difference in stuttering measures with and without treatment will be determined.

    Time frame: 4 month

07

Study locations

2 sites
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 13, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04173949
Responsible party
Sponsor
First posted
Nov 22, 2019
Start date
Mar 15, 2020
Primary completion
Dec 30, 2025 (estimated)
Completion
Dec 30, 2025 (estimated)
Last update
Mar 13, 2025

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.

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Discussion

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Studies of the drug tested here: Ramipril

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