Trial Outcomes & Findings for Treatment of Restless Legs Symptoms With Pramipexole to Improve the Outcomes of Protracted Opioid Withdrawal in OUD (NCT NCT04759703)

Last Updated: 2025-09-22

Results Overview

The International Restless Legs Syndrome Study Group Rating Scale (IRLS) is a 10-item patient-reported questionnaire designed to assess the severity of restless legs syndrome symptoms. Each item is scored from 0 (no symptoms) to 4 (very severe), for a total score range of 0 to 40, with higher scores indicating greater symptom severity. A negative change from baseline represents symptom improvement. Very severe=31-40 points Severe=21-30 points Moderate=11-20 points Mild=1-10 points None=0 points Change 2 weeks IRLS score minus baseline IRLS score

Recruitment status

TERMINATED

Study phase

PHASE2/PHASE3

Target enrollment

75 participants

Primary outcome timeframe

baseline and 2 weeks

Results posted on

2025-09-22

Participant Flow

Participants were recruited from the Gavin Foundation Clinical Stabilization Services in Quincy. A total of 175 patients were referred, 93 were screened, and 75 patients enrolled.

After screening, 18 of the 93 patients were found ineligible and 35 withdrew or failed. 40 completed post randomization baseline data.

Participant milestones

Participant milestones
Measure	Pramipexole 0.25 mg pramipexole tablets	Placebo Matching placebo tablets
Overall Study STARTED	20	20
Overall Study COMPLETED	13	11
Overall Study NOT COMPLETED	7	9

Reasons for withdrawal

Reasons for withdrawal
Measure	Pramipexole 0.25 mg pramipexole tablets	Placebo Matching placebo tablets
Overall Study Withdrawal by Subject	4	9
Overall Study Adverse Event	1	0
Overall Study Lost to Follow-up	2	0

Baseline Characteristics

Treatment of Restless Legs Symptoms With Pramipexole to Improve the Outcomes of Protracted Opioid Withdrawal in OUD

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Pramipexole n=20 Participants 0.25 mg pramipexole tablets	Placebo n=20 Participants Matching placebo tablets	Total n=40 Participants Total of all reporting groups
Age, Continuous	39.1 Years STANDARD_DEVIATION 9.6 • n=5 Participants	35.2 Years STANDARD_DEVIATION 5.8 • n=7 Participants	37.3 Years STANDARD_DEVIATION 8.2 • n=5 Participants
Sex: Female, Male Female	7 Participants n=5 Participants	3 Participants n=7 Participants	10 Participants n=5 Participants
Sex: Female, Male Male	13 Participants n=5 Participants	17 Participants n=7 Participants	30 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	3 Participants n=5 Participants	3 Participants n=7 Participants	6 Participants n=5 Participants
Race (NIH/OMB) White	15 Participants n=5 Participants	17 Participants n=7 Participants	32 Participants n=5 Participants
Race (NIH/OMB) More than one race	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=5 Participants	3 Participants n=7 Participants	4 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	19 Participants n=5 Participants	17 Participants n=7 Participants	36 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	20 Participants n=5 Participants	20 Participants n=7 Participants	40 Participants n=5 Participants
Subjective Opiate Withdrawal Scale (SOWS)	21.18 scores on a scale STANDARD_DEVIATION 10.00 • n=5 Participants	26.40 scores on a scale STANDARD_DEVIATION 10.61 • n=7 Participants	23.93 scores on a scale STANDARD_DEVIATION 10.52 • n=5 Participants
International Restless Legs Syndrome Study Group Rating Scale (IRLS)	14.94 scores on a scale STANDARD_DEVIATION 1.99 • n=5 Participants	14.71 scores on a scale STANDARD_DEVIATION 1.89 • n=7 Participants	14.85 scores on a scale STANDARD_DEVIATION 1.92 • n=5 Participants

PRIMARY outcome

Timeframe: baseline and 2 weeks

Outcome measures

Outcome measures
Measure	Pramipexole n=13 Participants Medication arm; 0.25mg of pramipexole	Placebo n=11 Participants Placebo arm; 0.25 mg of placebo
Change From Baseline International RLS Severity Score (IRLS) at 2 Weeks	-7.04 scores on a scale Standard Deviation 3.44	-9.15 scores on a scale Standard Deviation 6.56

SECONDARY outcome

Timeframe: baseline and 2 weeks

The Subjective Opiate Withdrawal Scale (SOWS) is a 16-item self-administered instrument. Self-administered scale for grading opioid withdrawal symptoms. Scored from 0-64. Summed from 16 sub-scale questions rated by the patient from 0 to 4. Mild Withdrawal = score of 1 - 10 Moderate withdrawal = 11 - 20 Severe withdrawal = 21 - 30+ Change in SOWS score (2 weeks minus baseline)

Outcome measures

Outcome measures
Measure	Pramipexole n=13 Participants Medication arm; 0.25mg of pramipexole	Placebo n=11 Participants Placebo arm; 0.25 mg of placebo
Change From Baseline Subjective Opiate Withdrawal Scale (SOWS) at 2 Weeks	-11.60 scores on a scale Standard Deviation 11.88	-18.28 scores on a scale Standard Deviation 13.41

Adverse Events

Pramipexole

Serious events: 0 serious events

Other events: 15 other events

Deaths: 0 deaths

Placebo

Serious events: 0 serious events

Other events: 8 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Pramipexole n=20 participants at risk 0.25 mg pramipexole tablets	Placebo n=20 participants at risk Matching placebo tablets
Gastrointestinal disorders Stomach cramps	20.0% 4/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	15.0% 3/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Gastrointestinal disorders Constipation	10.0% 2/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	0.00% 0/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Gastrointestinal disorders Nausea	20.0% 4/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	5.0% 1/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Nervous system disorders Headaches	10.0% 2/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	5.0% 1/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Nervous system disorders Worsened RLS	5.0% 1/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	0.00% 0/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
General disorders Drowsiness	15.0% 3/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	5.0% 1/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Nervous system disorders Jumpiness	0.00% 0/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	5.0% 1/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Nervous system disorders Muscle twitches	0.00% 0/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	5.0% 1/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Gastrointestinal disorders Dry Mouth	0.00% 0/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	10.0% 2/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.
Psychiatric disorders Vivid Dreams	15.0% 3/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.	0.00% 0/20 • From enrollment through study termination, up to 2 weeks after randomization Adverse events were collected daily by systemic assessment during inpatient stay and study visits.

Additional Information

John W. Winkelman, MD, PhD

Massachusetts General Hospital

Phone: 6176436026

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place