PainPhase 4NCT07542730
Diphenhydramine as an Adjunct to Moderate Sedation for Procedural First Trimester Abortions
A Phase 4 study testing Diphenhydramine in people with Pain and Abortion, run by University of Rochester at 1 site in United States.
Trial summary
This single center, double blind, randomized controlled trial will evaluate whether adding intravenous diphenhydramine to a standard moderate sedation regimen improves pain control during first trimester procedural abortion. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- What is being tested?
- Diphenhydramine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 98 participants
- Where
- 1 siteUnited States
- Study dates
- 29 Jun 2026to Feb 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults age 18 years and older
- Desire procedural abortion with moderate sedation
- Gestational age less than or equal to 13 weeks
- Intrauterine pregnancy or pregnancy of unknown location
- Body mass index less than or equal to 40
Who cannot join
- Desire medical abortion or desire to continue pregnancy
- Gestational age greater than 13 weeks
- Body mass index greater than 40
- Age younger than 18 years
- Confirmed ectopic pregnancy
- Medical condition that is a contraindication to moderate sedation as determined by the treating clinician
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Gender Wellness OB/GYN
Rochester, New York, 14642
About this study
This single center, double blind, randomized controlled trial will evaluate whether adding intravenous diphenhydramine to a standard moderate sedation regimen improves pain control during first trimester procedural abortion. Participants undergoing uterine aspiration at less than 13 weeks gestation will be randomized 1 to 1 to receive standard moderate sedation with midazolam and fentanyl plus either diphenhydramine 50 mg intravenously or matching placebo. The primary outcome is participant reported pain during uterine aspiration measured by a 100 mm Visual Analog Scale.
Read the detailed description
Surgical abortion is commonly associated with pain and anxiety despite use of local anesthesia and moderate sedation. This study will evaluate the efficacy of intravenous diphenhydramine as an adjunct to a standard moderate sedation regimen for participants undergoing first trimester procedural abortion.
This is a single center, double blind, randomized, placebo controlled trial conducted at the University of Rochester Family Planning Clinic and Strong Memorial Hospital. Participants undergoing first trimester uterine aspiration at less than or equal to 13 weeks gestation will be randomized in a 1 to 1 ratio using a computer generated block randomization scheme to receive either intravenous diphenhydramine 50 mg or matching placebo, in addition to standard moderate sedation with midazolam and fentanyl. Participants, clinical staff, and outcome assessors will remain blinded to treatment assignment.
Pain will be assessed using a 100 mm Visual Analog Scale at baseline, during speculum placement, paracervical block, cervical dilation, uterine aspiration, 10 minutes after the procedure, and 1 hour after the procedure. Sedation depth during uterine aspiration will be assessed using the Modified Observer's Assessment of Alertness Sedation scale. Additional outcomes include total sedative medication dose, time to readiness for discharge, and sedation related adverse events.
- Being tested
- Diphenhydramine, Placebo
- Medical subject headings
- Pain, Anxiety Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DiphenhydramineDrug
Also called Bendaryl
Diphenhydramine 50 mg administered intravenously once prior to the procedure.
PlaceboDrug
Matching placebo composed of normal saline administered intravenously once prior to the procedure.
| Study group | Role | What they receive |
|---|---|---|
| Diphenhydramine plus standard moderate sedation | Experimental | Participants receive intravenous diphenhydramine 50 mg prior to the procedure, in addition to standard moderate sedation with midazolam and fentanyl. Additional doses of midazolam and fentanyl may be administered during the procedure as clinically indicated. Receives: Drug: Diphenhydramine |
| Placebo plus standard moderate sedation | Placebo comparator | Participants receive a matching intravenous placebo (normal saline) prior to the procedure, in addition to standard moderate sedation with midazolam and fentanyl. Additional doses of midazolam and fentanyl may be administered during the procedure as clinically indicated. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Participant-Reported Pain During Uterine Aspiration
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS). The VAS ranges from 0 to 100 mm, where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures the participant's perceived pain during uterine aspiration.
Measured: During the procedure, at the time of uterine aspiration
Secondary outcomes (8)
Sedation Depth During Uterine Aspiration
Sedation depth will be assessed using the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. The MOAA/S scale ranges from 0 to 5, where 5 indicates fully alert and 0 indicates no response to painful stimulus. Lower scores indicate deeper levels of sedation. This outcome measures the level of sedation achieved during uterine aspiration.
Measured: During the procedure, at the time of uterine aspiration
Participant-Reported Pain at Speculum Placement
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS), where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures pain experienced during speculum placement.
Measured: During the procedure, at the time of speculum placement
Participant-Reported Pain at Paracervical Block
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS), where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures pain experienced during administration of the paracervical block.
Measured: During the procedure, at the time of Paracervical Block
Participant-Reported Pain at Cervical Dilation
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS), where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures pain experienced during cervical dilation.
Measured: During the procedure, at the time of Cervical Dilation
Participant-Reported Pain 10 Minutes After Procedure Completion
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS), where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures post-procedure pain at 10 minutes.
Measured: 10 minutes after completion of the procedure
Participant-Reported Pain 1 Hour After Procedure Completion
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS), where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures post-procedure pain at 1 hour.
Measured: 1 hour after completion of the procedure
Time to Readiness for Discharge
Time from procedure completion to when the participant meets discharge criteria, measured in minutes. Higher values indicate longer recovery time.
Measured: From completion of the procedure until discharge readiness, up to approximately 2 hours
Incidence of Sedation-Related Adverse Events
Number and proportion of participants experiencing sedation-related adverse events, including hypoxia, hypotension, use of reversal agents (naloxone or flumazenil), paradoxical agitation, respiratory depression requiring supplemental oxygen beyond nasal cannula, hypotension requiring vasopressors, or unplanned hospital admission. Higher values indicate greater incidence of adverse events.
Measured: From administration of study medication through discharge on the day of procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2026
- Study start29 Jun 2026
- Primary completionFeb 2027 (estimated)
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PainStudies of the same condition, open and under way.
- More trials run by University of RochesterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 98 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Rochester
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Stacy Sun, University of Rochester
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07542730
- Sponsor's protocol ID
- STUDY00011436
- Status last verified
- Aug 2026
- First submitted
- 10 Apr 2026
- Last updated
- 21 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diphenhydramine as an Adjunct to Moderate Sedation for Procedural First Trimester Abortions
- ClinicalTrials.gov ID
- NCT07542730
- Acronym / sponsor ID
- STUDY00011436
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 98 participants (estimated)
- Lead sponsor
- University of RochesterUniversity, hospital or other
- Study start
- 29 Jun 2026 (actual)
- Primary completion
- Feb 2027 (estimated)
- Study completion
- Feb 2027 (estimated)
- First posted
- 21 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This single center, double blind, randomized controlled trial will evaluate whether adding intravenous diphenhydramine to a standard moderate sedation regimen improves pain control during first trimester procedural abortion. Participants undergoing uterine aspiration at less than 13 weeks gestation will be randomized 1 to 1 to receive standard moderate sedation with midazolam and fentanyl plus either diphenhydramine 50 mg intravenously or matching placebo. The primary outcome is participant reported pain during uterine aspiration measured by a 100 mm Visual Analog Scale.
Detailed description
Surgical abortion is commonly associated with pain and anxiety despite use of local anesthesia and moderate sedation. This study will evaluate the efficacy of intravenous diphenhydramine as an adjunct to a standard moderate sedation regimen for participants undergoing first trimester procedural abortion.
This is a single center, double blind, randomized, placebo controlled trial conducted at the University of Rochester Family Planning Clinic and Strong Memorial Hospital. Participants undergoing first trimester uterine aspiration at less than or equal to 13 weeks gestation will be randomized in a 1 to 1 ratio using a computer generated block randomization scheme to receive either intravenous diphenhydramine 50 mg or matching placebo, in addition to standard moderate sedation with midazolam and fentanyl. Participants, clinical staff, and outcome assessors will remain blinded to treatment assignment.
Pain will be assessed using a 100 mm Visual Analog Scale at baseline, during speculum placement, paracervical block, cervical dilation, uterine aspiration, 10 minutes after the procedure, and 1 hour after the procedure. Sedation depth during uterine aspiration will be assessed using the Modified Observer's Assessment of Alertness Sedation scale. Additional outcomes include total sedative medication dose, time to readiness for discharge, and sedation related adverse events.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Diphenhydramine plus standard moderate sedation | Experimental | Drug: DiphenhydramineParticipants receive intravenous diphenhydramine 50 mg prior to the procedure, in addition to standard moderate sedation with midazolam and fentanyl. Additional doses of midazolam and fentanyl may be administered during the procedure as clinically indicated. |
| Placebo plus standard moderate sedation | Placebo comparator | Drug: PlaceboParticipants receive a matching intravenous placebo (normal saline) prior to the procedure, in addition to standard moderate sedation with midazolam and fentanyl. Additional doses of midazolam and fentanyl may be administered during the procedure as clinically indicated. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Adults age 18 years and older
- Desire procedural abortion with moderate sedation
- Gestational age less than or equal to 13 weeks
- Intrauterine pregnancy or pregnancy of unknown location
- Body mass index less than or equal to 40
Key exclusion criteria (6 listed)
- Desire medical abortion or desire to continue pregnancy
- Gestational age greater than 13 weeks
- Body mass index greater than 40
- Age younger than 18 years
- Confirmed ectopic pregnancy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| DiphenhydramineAlso: BendarylDiphenhydramine 50 mg administered intravenously once prior to the procedure. | Drug | Diphenhydramine plus standard moderate sedation |
| PlaceboMatching placebo composed of normal saline administered intravenously once prior to the procedure. | Drug | Placebo plus standard moderate sedation |
Primary outcome
Participant-Reported Pain During Uterine Aspiration
Time frame: During the procedure, at the time of uterine aspiration
Pain intensity will be measured using a 100 mm Visual Analog Scale (VAS). The VAS ranges from 0 to 100 mm, where 0 represents "no pain" and 100 represents "worst pain imaginable." Higher scores indicate greater pain intensity. This outcome measures the participant's perceived pain during uterine aspiration.
8 secondary outcomes
Sedation Depth During Uterine Aspiration
Time frame: During the procedure, at the time of uterine aspiration
Participant-Reported Pain at Speculum Placement
Time frame: During the procedure, at the time of speculum placement
Participant-Reported Pain at Paracervical Block
Time frame: During the procedure, at the time of Paracervical Block
Participant-Reported Pain at Cervical Dilation
Time frame: During the procedure, at the time of Cervical Dilation
Participant-Reported Pain 10 Minutes After Procedure Completion
Time frame: 10 minutes after completion of the procedure
Participant-Reported Pain 1 Hour After Procedure Completion
Time frame: 1 hour after completion of the procedure
Time to Readiness for Discharge
Time frame: From completion of the procedure until discharge readiness, up to approximately 2 hours
Incidence of Sedation-Related Adverse Events
Time frame: From administration of study medication through discharge on the day of procedure
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Aug 2026.
Related trials for Pain
Not yet recruiting
Effect of Stress Ball Use During Femoral Arterial Sheath Removal After Coronary Angiography
Femoral Arterial Sheath Removal, Stress Ball
Recruiting
Empowered Relief® for Cancer Survivors With Chronic Pain
Chronic Pain Due to Cancer, Pain Catastrophizing
RecruitingPhase 4
ESP Blocks for Posterior Spinal Fusion
Postoperative Pain
RecruitingObservational study
Pain Phenotypes in Individuals With Multiple Sclerosis
Multiple Sclerosis, Chronic Pain
Not yet recruiting
Effects of Hip Hinge Exercises on Pain, Range of Motion and Functional Disability in Non-specific Low Back Pain.
Low Back Pain
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Diphenhydramine in people with Pain and Abortion, run by University of Rochester at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sarah Cavegila, MPH (585-273-5734, Sarah_Caveglia@URMC.Rochester.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Participant-Reported Pain During Uterine Aspiration (time frame: During the procedure, at the time of uterine aspiration). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Aug 2026.