Trial Outcomes & Findings for The Use of Low Dose Metronidazole to Decrease Postoperative Pain After Endometriosis Surgery (NCT NCT04554693)

Results Overview

The outcome of binary, subject pain persistence, assessed as yes or no, will be compared between groups using the Fisher exact test.

Recruitment status

TERMINATED

Study phase

PHASE4

Target enrollment

78 participants

Primary outcome timeframe

6 weeks postoperatively.

Results posted on

2026-06-18

Participant Flow

Excluded=64 Declined to participate=36 Did not meet inclusion criteria=28

Participant milestones

Participant milestones
Measure	Metronidazole Participants took metronidazole 250 mg oral three times a day for 14 days after surgery.	Placebo Participants took Halal and Kosher certified gelatin placebo capsules orally three times a day for 14 days after surgery.
Overall Study STARTED	41	37
Overall Study COMPLETED	38	34
Overall Study NOT COMPLETED	3	3

Reasons for withdrawal

Reasons for withdrawal
Measure	Metronidazole Participants took metronidazole 250 mg oral three times a day for 14 days after surgery.	Placebo Participants took Halal and Kosher certified gelatin placebo capsules orally three times a day for 14 days after surgery.
Overall Study Withdrawal by Subject	3	3

Baseline Characteristics

no male participants due to prevalence of disease in female only population

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Metronidazole n=38 Participants Participants took metronidazole 250 mg oral three times a day for 14 days after surgery.	Placebo n=34 Participants Participants took Halal and Kosher certified gelatin placebo capsules oral three times a day for 14 days after surgery.	Total n=72 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=20 Participants	0 Participants n=20 Participants	0 Participants n=40 Participants
Age, Categorical Between 18 and 65 years	38 Participants n=20 Participants	34 Participants n=20 Participants	72 Participants n=40 Participants
Age, Categorical >=65 years	0 Participants n=20 Participants	0 Participants n=20 Participants	0 Participants n=40 Participants
Sex/Gender, Customized females analyzed	38 Participants n=20 Participants • no male participants due to prevalence of disease in female only population	34 Participants n=20 Participants • no male participants due to prevalence of disease in female only population	72 Participants n=40 Participants • no male participants due to prevalence of disease in female only population
Race/Ethnicity, Customized White	30 Participants n=20 Participants	25 Participants n=20 Participants	55 Participants n=40 Participants
Race/Ethnicity, Customized Non-White	8 Participants n=20 Participants	9 Participants n=20 Participants	17 Participants n=40 Participants
Region of Enrollment United States	38 participants n=20 Participants	34 participants n=20 Participants	72 participants n=40 Participants

PRIMARY outcome

Timeframe: 6 weeks postoperatively.

The outcome of binary, subject pain persistence, assessed as yes or no, will be compared between groups using the Fisher exact test.

Outcome measures

Outcome measures
Measure	Metronidazole n=38 Participants Metronidazole Metronidazole Oral: 250 mg oral three times a day for 14 days	Placebo n=34 Participants Halal and Kosher certified gelatin placebo capsules Placebo: Halal and Kosher certified gelatin placebo capsules oral three times a day for 14 days
Percentage of Participants With Self Reported Pain Persistence	84 Percentage with persistence of pain	88 Percentage with persistence of pain

SECONDARY outcome

Timeframe: 6 weeks postoperatively.

Endometriosis Health Profile-5 on scale of 0-100, with higher scores meaning worse outcome, using continuous variables reported as means.

Outcome measures

Outcome measures
Measure	Metronidazole n=38 Participants Metronidazole Metronidazole Oral: 250 mg oral three times a day for 14 days	Placebo n=34 Participants Halal and Kosher certified gelatin placebo capsules Placebo: Halal and Kosher certified gelatin placebo capsules oral three times a day for 14 days
Quality of Life Via Endometriosis Health Profile-5	42.6 score on a scale Standard Deviation 23.5	41.1 score on a scale Standard Deviation 24.6

SECONDARY outcome

Timeframe: 6 weeks postoperatively.

Female sexual function index on a scale of 2-36 with higher scores meaning higher sexual dysfunction

Outcome measures

Outcome measures
Measure	Metronidazole n=38 Participants Metronidazole Metronidazole Oral: 250 mg oral three times a day for 14 days	Placebo n=34 Participants Halal and Kosher certified gelatin placebo capsules Placebo: Halal and Kosher certified gelatin placebo capsules oral three times a day for 14 days
Sexual Health Via Female Sexual Function Index	22.2 score on a scale of 2-36 Interval 2.0 to 36.0	23.5 score on a scale of 2-36 Interval 2.0 to 36.0

SECONDARY outcome

Timeframe: 6 months postoperatively.

Population: This outcome measure data was not collected as study was terminated. We collected 6 weeks of postoperative data. This data is reported is reported in the table for primary outcome measure #1.

The outcome of binary, subject pain persistence, assessed as yes or no, will be compared between groups using the Fisher exact test.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 1 year postoperatively.

Population: This outcome measure data was not collected as study was terminated. We collected 6 weeks of postoperative data. This data is reported is reported in the table for primary outcome measure #1.

The outcome of binary, subject pain persistence, assessed as yes or no, will be compared between groups using the Fisher exact test.

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: 1 year postoperatively

Population: This outcome measure data was not collected since only the primary outcome at the 6-week post op timepoint was collected and analyzed .

Number of pregnancies and miscarriages postoperatively will be compared

Outcome measures

Outcome data not reported

OTHER_PRE_SPECIFIED outcome

Timeframe: 5 years postoperatively

Population: This outcome measure data was not collected since only the primary outcome at the 6-week post op timepoint was collected and analyzed .

Number of pregnancies and miscarriages postoperatively will be compared

Outcome measures

Outcome data not reported

Adverse Events

Metronidazole

Serious events: 0 serious events

Other events: 3 other events

Deaths: 0 deaths

Placebo

Serious events: 0 serious events

Other events: 4 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	Metronidazole n=38 participants at risk Metronidazole Metronidazole Oral: 250 mg oral three times a day for 14 days	Placebo n=34 participants at risk Halal and Kosher certified gelatin placebo capsules Placebo: Halal and Kosher certified gelatin placebo capsules oral three times a day for 14 days
Surgical and medical procedures Clavien-Dindo Grade One	5.3% 2/38 • Number of events 2 • baseline through 6 weeks post-op.	8.8% 3/34 • Number of events 3 • baseline through 6 weeks post-op.
Surgical and medical procedures Clavien-Dindo Grade two	2.6% 1/38 • Number of events 1 • baseline through 6 weeks post-op.	2.9% 1/34 • Number of events 1 • baseline through 6 weeks post-op.

Additional Information

Dr. Resad Pasic

University of Louisville

Phone: 502-561-7465

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place