A Phase 4 interventional study of Misoprostol Tabets and Placebo in Fibroids, Uterine, Fluid Deficit and Hysteroscopy / Methods, sponsored by Northwestern University. Recruiting at 1 site in United States. Open to female participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-06-01.
Sponsored by Northwestern University · Phase 4, Interventional, and Treatment
The goal of this double blinded randomized control trial is to evaluate the impact of misoprostol on fluid deficit during hysteroscopic myomectomies. The main questions it aims to answer are:
Is there is difference in fluid deficit in patients who receive misoprostol vs placebo pre operatively for hysteroscopic myomectomies?
Participants will be randomized to received 800 mcg of either rectal misoprostol prior to their hysteroscopic myomectomy or 4 tablets of placebo (ZEEBO) prior to their hysteroscopic myomectomy.
Misoprostol is a synthetic analogue of prostaglandin E1 originally developed for the prevention and treatment of NSAID-induced peptic ulcers. Over time, it has become widely used in obstetrics and gynecology due to its uterotonic properties. It is FDA-approved as part of the regimen, paired with mifepristone, for medical abortion and is commonly used off-label for cervical ripening, management of postpartum hemorrhage, and preoperative preparation for gynecologic procedures. In non-pregnant women, misoprostol is frequently administered prior to procedures such as hysteroscopy, intrauterine device insertion, and endometrial biopsy to facilitate cervical dilation. It can be delivered via multiple routes, including oral, sublingual, buccal, vaginal, and rectal. Rectal administration typically results in onset of action within 10-20 minutes, peak plasma concentrations at 60-80 minutes, and a duration of action of approximately 3-4 hours due to its short half-life (20-40 minutes). Its uterotonic effects are mediated by increased intracellular calcium, which activates myosin light-chain kinase. Reported side effects include cramping, bleeding, fever, shivering, nausea, vomiting, and diarrhea, though these are generally mild and dose dependent. Previous studies have evaluated misoprostol's ability to reduce intraoperative blood loss during abdominal and laparoscopic myomectomy, typically using a single preoperative administered vaginally or rectally. These studies demonstrated significant reductions in blood loss. In gynecologic practice, doses ranging from 400 to 1000 mcg are commonly used and well tolerated.
Our study focuses on hysteroscopic myomectomy, a minimally invasive procedure performed via the cervix using a hysteroscope to visualize and resect submucosal fibroids within the uterine cavity. Unlike abdominal or laparoscopic approaches, hysteroscopic procedures are not associated with significant blood loss. Instead, the primary intraoperative concern is fluid overload. This can occur when the distension medium, typically normal saline (NS), is absorbed systemically through exposed vascular channels. Although NS is isotonic and does not disrupt electrolyte balance, excessive absorption can lead to complications such as pulmonary edema, cardiac strain, and peripheral edema. To mitigate this risk, national and institutional guidelines recommend terminating the procedure when the fluid deficit (the difference between the volume instilled and the volume recovered) reaches 2.5 liters.
Misoprostol's uterotonic properties may help reduce fluid absorption by promoting uterine contractions and limiting vascular exposure, potentially allowing the procedure to be more complete without exceeding fluid safety thresholds. This potential benefit is biologically plausible and clinically relevant. We have selected a dose of 800 mcg rectally, which is within the established safe and commonly used range in gynecologic practice. This dose is expected to be well tolerated and does not increase risk to participants.To maintain blinding, participants in the placebo arm will receive four Zeebo-branded tablets, each containing 250 milligrams, in weight, of microcrystalline cellulose, administered rectally to match the appearance and administration of the active drug. Zeebo is an inert placebo with no pharmacologic activity, and additional risks are minor.
STUDY ENDPOINTS:
Primary endpoint:
Secondary endpoints:
438 studies on the registry are indexed under Leiomyoma; 74 are open to participants now.
This study's planned enrollment of 40 is below the median of 66 across 306 interventional studies indexed under Leiomyoma.
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Exclusion Criteria:
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients will received 800 mcg of misoprostol per rectum prior to procedure.
Drug: Misoprostol Tabets
Patient will receive 4 tablets of placebo (ZEEBO) per rectum prior to procedure.
Drug: Placebo
800 mcg of misoprostol will be administered per rectum to intervention group prior to their scheduled hysteroscopic myomectomy.
4 tablets of Zeebo (Microcsrystalline cellulose) placebo tablets will be placed per rectum to prior to undergoing a hysteroscopic myomectomy, for patients assigned to the placebo arm.
Fluid Deficit
Primary outcome is difference in fluid deficit at the conclusion of the hysteroscopic myomectomy
Time frame: Immediately at the conclusion of the procedure.
Total fluid volume
Difference in total fluid volume used (in milliliters) between groups.
Time frame: intraoperative
Time
Difference in total procedure time (in minutes) between groups.
Time frame: Intraop
Reoperation
Frequency of repeat hysteroscopic myomectomy due to incomplete fibroid resection caused by early termination of the initial procedure
Time frame: within 3 month post op
Specimen weight
Total specimen weight
Time frame: Immediately post op
Plan to share: No — Plan to present data in aggregate for publication once study completed, individual participant data will not be shared.
Started Dec 2025 (actual). Primary completion is estimated for Dec 2026, 12 months after the start.
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