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Botulinum Toxin for Pelvic Pain in Women With Endometriosis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01553201
Recruitment Status : Completed
First Posted : March 14, 2012
Last Update Posted : February 7, 2020
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) )

Brief Summary:


- Some women with endometriosis have chronic pelvic pain. This pain may be caused by spasms of the pelvic floor muscles. These spasms can be detected by an examination. Studies suggest that botulinum toxin can help treat problems caused by muscle spasms. Researchers want to see if botulinum toxin injections into the pelvic floor muscles can decrease pain and spasms in women with pelvic pain.


- To see if botulinum toxin can relieve pain from pelvic floor spasm in women with pelvic pain.


- Women between 18 and 50 years of age with pain associated with pelvic muscle spasm and endometriosis. Pain must be persistent (lasting for at least 3 months).


  • Participants will keep a pain diary and record their pain medication use for a month before the first visit.
  • Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected. Participants will also answer questions about their pain levels and quality of life.
  • Participants will receive either botulinum toxin or a placebo (salt water) injection. The injection will be given into the pelvic floor muscles through the vaginal wall. Participants will take a muscle relaxant like Valium and have anesthetic cream put on the vaginal wall before the injection.
  • After the injection, participants will keep a pain diary for another month.
  • At a 1-month followup visit, participants will answer questions about their pain. If the pain has not improved, all participants may have a botulinum toxin injection (no placebo) into the pelvic floor muscles as before.
  • Participants will have followup visits for up to a year after the initial 1-month followup visit.

Condition or disease Intervention/treatment Phase
Endometriosis Chronic Pelvic Pain Pelvic Muscle Spasms Quality of Life Drug: Botuninum toxin A Drug: Placebo Phase 1 Phase 2

Detailed Description:

Chronic pelvic pain associated with endometriosis is poorly understood. Some women with chronic pelvic pain have muscle spasm of their pelvic muscles. Muscle spasm may be a significant part of pain in women with endometriosis and other types of chronic pelvic pain. Botulinum toxin injection is widely used to treat conditions associated with excessive muscle activity and spasm. Studies of botulinum toxin injected into pelvic muscles of women with pelvic pain have shown a decrease pain and spasm, but too few women have been studied to conclude its effectiveness. We expect to show that botulinum toxin injection in women with pelvic pain will relieve some of their pelvic pain.

Eligible subjects will be otherwise healthy women who have chronic pelvic pain and a history of endometriosis. Subjects will be randomized to either botulinum toxin injection or placebo (salt water) injection. After one month, we will evaluate the presence of the pain and all women will be offered botulinum toxin injection. We will also evaluate the need for reinjection.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 33 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: The Effectiveness of Botulinum Toxin on Persistent Pelvic Pain in Women With Endometriosis
Actual Study Start Date : July 30, 2014
Actual Primary Completion Date : July 31, 2018
Actual Study Completion Date : July 24, 2019

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Botulinum Toxin Drug: Botuninum toxin A
Placebo Comparator: Placebo Drug: Placebo

Primary Outcome Measures :
  1. Improvement in pain - a binary measurement of improvement/no improvement will be used.

Secondary Outcome Measures :
  1. 1) Need for re-injection at 1 month as a binary measurement of yes/no; 2) Change in Pelvic Pain: Pain visual analog score; 3) Botulinum toxin patient response inventory; 4) Standardized Pelvic Pain questionnaire; 5) Standardized QOL questionnair...

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
  • Female gender
  • Age between 18 and 55
  • History of endometriosis at surgery
  • Persistent pelvic pain for at least 3 months
  • Pelvic floor spasm
  • Negative pregnancy test (in women who have not had a hysterectomy)
  • Willing to use reliable method of contraception for the month after botulinum toxin injection including oral contraceptives, IUD, and barrier with spermicide.
  • Willing and able to give informed consent
  • Willing and able to comply with study requirements


  • Women with other causes of chronic pelvic pain including infectious, gastrointestinal, psychological disorders, fibromyalgia and chronic fatigue syndrome based on review of medical history within 1 year of first study visit,
  • Untreated severe cervical dysplasia or other gynecologic condition clinically significant abnormalities on physical or laboratory examinations that require evaluation or treatment or that would make participation unsafe
  • Hysterectomy and bilateral salpingo-oophorectomy
  • Pregnancy
  • Lactation
  • Allergy to albumen or botulinum toxin
  • Presence of antibodies to botulinum toxin or loss of response to previous injections for any indication
  • A known neuromuscular junction disorder such as myasthenia gravis or Eaton-Lambert syndrome
  • History of urinary or fecal incontinence
  • Known pelvic prolapse

    • Eligibility will be based on a physical exam at NIH at the first study visit, as well as history and available medical records within 1 year before the study visit. Negative test results will be documented to confirm study eligibility. If the Pap and the GC and chlamydia tests were not done outside of the NIH within the previous year, or if documentation of the negative test results is not available, we will await the results of the screening tests done at the NIH before administering the study medication.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01553201

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United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
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Principal Investigator: Barbara I Karp, M.D. National Institute of Neurological Disorders and Stroke (NINDS)

Additional Information:
Publications automatically indexed to this study by Identifier (NCT Number):
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Responsible Party: National Institute of Neurological Disorders and Stroke (NINDS) Identifier: NCT01553201    
Other Study ID Numbers: 120083
First Posted: March 14, 2012    Key Record Dates
Last Update Posted: February 7, 2020
Last Verified: September 2018

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) ):
Quality of Life
Botulinum Toxin A
Pelvic Pain Spasm
Chronic Pelvic Pain
Additional relevant MeSH terms:
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Pelvic Pain
Genital Diseases, Female
Neurologic Manifestations
Signs and Symptoms
Neuromuscular Manifestations
Nervous System Diseases
Botulinum Toxins
Acetylcholine Release Inhibitors
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Cholinergic Agents
Neurotransmitter Agents
Physiological Effects of Drugs