Overview
The objective of the study is to evaluate the global impression of improvement at 3 months following intramyometrial botulinum toxin injections via hysteroscopy in women with severe primary dysmenorrhea who have failed first-line medical treatment, compared to intramyometrial placebo injections.
Description
This trial is multicenter, placebo-controlled, randomized with center-based stratification, double-blind and prospective. The treatment consists of a single injection follow by 6 months of follow-up.
Eligibility
Inclusion Criteria:
- Adult women who are not menopausal,
- Experiencing severe dysmenorrhea, defined as an average pain intensity score ≥ 6/10 on a Numerical Rating Scale (NRS) over the past 3 months at the inclusion visit,
- Having failed optimal first-line medical treatment combining hormonal therapy and appropriate analgesics (Level I and II analgesics, and NSAIDs),
- Having undergone a pelvic MRI within 6 months prior to the inclusion visit that shows no evidence of deep infiltrating endometriosis or endometrioma, following systematic review by radiologists from the expert center managing the patient (if the pelvic MRI is deemed of insufficient quality for interpretation, a new MRI will be performed at the center),
- Using a highly effective method of contraception (failure rate \<1%) for the entire duration of the follow-up period. Highly effective contraception methods are defined as one of the following: combined hormonal contraception (containing estrogen and progestin) with ovulation inhibition (oral, vaginal, or transdermal), progestin-only hormonal contraception with ovulation inhibition (oral, injectable, or implantable), intrauterine device (IUD), intrauterine hormonal system (IUS), condoms, bilateral tubal occlusion, vasectomized partner, or sexual abstinence,
- Having a negative urine pregnancy test on the day of the procedure,
- Having signed the informed consent form for the study at the M-1 visit.
Exclusion Criteria:
- Pregnant or planning a pregnancy during the entire study period,
- Currently breastfeeding,
- Refusal to use effective contraception during the study and for 6 months after its completion,
- Contraindications to botulinum toxin, including:
- Generalized disorders of muscular activity (e.g., myasthenia gravis, Lambert-Eaton syndrome),
- Ongoing treatment with aminoglycosides, peripheral muscle relaxants, or amino-4-quinolines,
- Hypersensitivity to the active substance, human albumin, or sucrose,
- Bleeding disorders or current treatment with anticoagulants,
- Ongoing vaginal or upper genital tract infection,
- Participation in another interventional clinical trial,
- Inability to cooperate or understand the study requirements in a way that would allow strict adherence to the protocol,
- Subject to legal protection measures (e.g., guardianship, curatorship, or judicial protection),
- Not affiliated with the French social security system,
- Unable to access the internet to complete questionnaires at Month 1 and Month 6.
