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Botulinum Toxin for Pelvic Pain in Women With Endometriosis

This study is currently recruiting participants. (see Contacts and Locations)
Verified March 22, 2017 by National Institutes of Health Clinical Center (CC)
Information provided by (Responsible Party):
National Institutes of Health Clinical Center (CC) ( National Institute of Neurological Disorders and Stroke (NINDS) ) Identifier:
First received: March 10, 2012
Last updated: April 20, 2017
Last verified: March 22, 2017


- 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 Intervention Phase
Botulinum Toxin A
Chronic Pelvic Pain
Pelvic Muscle Spasms
Quality of Life
Drug: Botuninum toxin A
Phase 1
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double Blind (masked roles unspecified)
Primary Purpose: Treatment
Official Title: The Effectiveness of Botulinum Toxin on Persistent Pelvic Pain in Women With Endometriosis

Resource links provided by NLM:

Further study details as provided by National Institutes of Health Clinical Center (CC):

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

Secondary Outcome Measures:
  • 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...

Estimated Enrollment: 30
Study Start Date: February 24, 2012
Estimated Study Completion Date: December 31, 2019
Estimated Primary Completion Date: July 1, 2017 (Final data collection date for primary outcome measure)
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.


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 50
  • History of endometriosis at surgery
  • Persistent pelvic pain for at least 3 months
  • Pelvic floor spasm
  • Negative pregnancy test
  • Willing to use reliable method of contraception for the month after botulinum toxin injection
  • 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 within the past year based on medical record review*.
  • Significant abnormalities in the physical or laboratory examination including renal and liver function more than twice the normal range
  • 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

    • Pap smear and GC and chlamydia cultures will be obtained at the time of study screening, but results may not be available until after the 1st study injection. 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.
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01553201

Contact: Pamela Stratton, M.D. (301) 496-9079
Contact: Barbara I Karp, M.D. (301) 496-0150

United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike Recruiting
Bethesda, Maryland, United States, 20892
Contact: For more information at the NIH Clinical Center contact Patient Recruitment and Public Liaison Office (PRPL)    800-411-1222 ext TTY8664111010   
Sponsors and Collaborators
National Institute of Neurological Disorders and Stroke (NINDS)
Principal Investigator: Barbara I Karp, M.D. National Institute of Neurological Disorders and Stroke (NINDS)
  More Information

Additional Information:
Responsible Party: National Institute of Neurological Disorders and Stroke (NINDS) Identifier: NCT01553201     History of Changes
Other Study ID Numbers: 120083
Study First Received: March 10, 2012
Last Updated: April 20, 2017

Keywords provided by National Institutes of Health Clinical Center (CC):
Quality of Life
Botulinum Toxin A
Pelvic Pain Spasm
Chronic Pelvic Pain

Additional relevant MeSH terms:
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 processed this record on April 25, 2017