Analgesic Efficacy and Obstetric Effects of Tramadol, Paracetamol and Placebo in Active Labor (TRAMPA)

February 24, 2026 updated by: Ricardo A Gutierrez Ramirez, MD, MSc, FACOG, Universidad Nacional Autonoma de Honduras

Analgesic Efficacy and Obstetric Effects of Tramadol, Paracetamol and Placebo in Active Labor: A Randomized Double-Blind Controlled Trial

This randomized, double-blind, placebo-controlled trial aims to compare the analgesic efficacy and obstetric effects of tramadol (100 mg IV) versus paracetamol (1 g IV) versus placebo (saline solution) in nulliparous women during active labor. The primary outcome is duration of active labor (minutes). Secondary outcomes include duration of expulsive phase, type of delivery, need for oxytocin augmentation, maternal adverse events (nausea, vomiting, somnolence, hypotension), and neonatal outcomes (Apgar scores at 1 and 5 minutes, NICU admission). The study hypothesizes that tramadol significantly reduces active labor duration compared to paracetamol and placebo, without compromising maternal or neonatal safety. A total of 300 nulliparous women (100 per group) will be enrolled at Hospital Escuela, Tegucigalpa, Honduras.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is a randomized, double-blind, parallel-group, superiority efficacy trial comparing three interventions: tramadol 100 mg IV, paracetamol 1 g IV, and placebo (10 mL 0.9% saline solution) administered at the onset of active labor (cervical dilation ≥4 cm with regular contractions). The study design follows CONSORT guidelines for randomized controlled trials. Randomization will be performed using REDCap's automated randomization module in variable block sizes, ensuring allocation concealment. Double-blinding is maintained: participants, care providers, and outcome assessors are masked to group assignment. The primary endpoint is duration of active labor (minutes from intervention administration to complete cervical dilation). Secondary endpoints include: duration of expulsive phase (minutes), type of delivery (spontaneous vaginal, instrumental, cesarean), need for oxytocin augmentation, maternal adverse events (nausea, vomiting, somnolence, hypotension, pruritus, dizziness), neonatal Apgar scores at 1 and 5 minutes, birth weight, meconium-stained amniotic fluid, NICU admission, and neonatal asphyxia. Data collection includes sociodemographic variables (age, education, marital status, occupation), obstetric variables (gestational age, prenatal care visits, BMI, membrane status, cervical dilation at intervention, baseline fetal heart rate), and pain scores (Visual Analog Scale pre-intervention, 30 min, 1h, 2h post-intervention). Statistical analysis includes ANOVA or Kruskal-Wallis for continuous variables, chi-square for categorical variables, and logistic regression for binary outcomes, with significance set at p<0.05. A Data Safety Monitoring Board will oversee safety every 3 months. The study is funded by Universidad Nacional Autónoma de Honduras and will be conducted at Hospital Escuela, Tegucigalpa, from Feb. 2026 to June 2026.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Honduras
    • Francisco Morazán Department
      • Tegucigalpa, Francisco Morazán Department, Honduras, 11101
        • Recruiting
        • Hospital Escuela
        • Contact:
        • Principal Investigator:
          • Jessica M. Peña Ordoñez, MD
        • Sub-Investigator:
          • Jose A. Mendoza Rodriguez, MD
      • Tegucigalpa, Francisco Morazán Department, Honduras, 11101
        • Recruiting
        • Instituto Hondureño de Seguridad Social
        • Contact:
        • Principal Investigator:
          • Ethel A. Cruz Valdivieso, MD
        • Sub-Investigator:
          • Raphael Amador Umanzor, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Nulliparous pregnant women
  • Age between 15 and 45 years
  • Singleton pregnancy, term (37-41 weeks gestation)
  • Cephalic presentation
  • Active labor defined as cervical dilation ≥4 cm with regular contractions
  • Signed informed consent

Exclusion Criteria:

  • Multiple gestation or high-risk pregnancy (preeclampsia, gestational diabetes, etc.)
  • Known allergy or contraindication to tramadol or paracetamol
  • Recent use (less than 6 hours) of any analgesic medication
  • Previous cesarean section or other uterine surgery
  • Active infection or fever at admission
  • Inability to provide informed consent due to mental or communication conditions
  • Non-cephalic presentation
  • Rupture of membranes >18 hours without labor
  • Participation in another clinical trial within the last 3 months

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Tramadol Group
Participants receive a single dose of tramadol 100 mg intravenously at the onset of active labor (cervical dilation ≥4 cm with regular contractions).
Drug: Tramadol Hydrochloride
Tramadol 100 mg administered as a single intravenous dose at the onset of active labor. Tramadol is an atypical opioid analgesic with serotonin and noradrenaline reuptake inhibition properties. The dose is within standard clinical ranges for obstetric analgesia. Administration is performed by trained medical personnel following institutional protocols. Participants are monitored for adverse effects including nausea, vomiting, somnolence, dizziness, and hypotension.
Experimental: Paracetamol Group
Participants receive a single dose of paracetamol 1 g intravenously (slow infusion) at the onset of active labor (cervical dilation ≥4 cm with regular contractions).
Drug: Paracetamol (acetaminophen)
Paracetamol 1 g administered as a single intravenous slow infusion at the onset of active labor. Paracetamol is a central analgesic acting through COX-3 inhibition in the central nervous system. It is widely used during pregnancy and labor due to its favorable safety profile. Administration is performed by trained medical personnel following institutional protocols. Participants are monitored for adverse effects including nausea, vomiting, and allergic reactions (rare).
Placebo Comparator: Placebo Group
Participants receive a single dose of 10 mL 0.9% saline solution intravenously at the onset of active labor (cervical dilation ≥4 cm with regular contractions).
Drug: Placebo (Saline Solution)
Placebo consisting of 10 mL 0.9% saline solution administered as a single intravenous dose at the onset of active labor. The appearance and administration procedure are identical to the active interventions to maintain blinding. No pharmacological active ingredients are present. Administration is performed by trained medical personnel following institutional protocols.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Duration of Active Labor
Time Frame: From intervention administration (at active labor onset) up to 12 hours.
Time in minutes from administration of study intervention (at onset of active labor defined as cervical dilation ≥4 cm with regular contractions) to complete cervical dilation (10 cm) or delivery, whichever occurs first. Measured and recorded by attending obstetric staff using standardized timing protocols.
From intervention administration (at active labor onset) up to 12 hours.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Duration of Expulsive Phase (Second Stage)
Time Frame: During delivery, from complete cervical dilation up to 120 minutes.
Time in minutes from complete cervical dilation (10 cm) to fetal expulsion. Measured and recorded by attending obstetric staff.
During delivery, from complete cervical dilation up to 120 minutes.
Type of Delivery
Time Frame: At delivery
Classification of delivery outcome: spontaneous vaginal delivery, instrumental delivery (forceps or vacuum), or cesarean section. Assessed by attending obstetrician.
At delivery
Need for Oxytocin Augmentation
Time Frame: During labor (from intervention administration up to 24 hours).
Requirement for additional oxytocin administration to augment uterine contractions during labor. Recorded as yes/no, including dose and timing if applicable.
During labor (from intervention administration up to 24 hours).
Maternal Adverse Events
Time Frame: From intervention administration up to 24 hours postpartum.
Occurrence of any adverse events potentially related to the intervention, including: nausea, vomiting, somnolence, dizziness, headache, pruritus, hypotension (systolic BP <90 mmHg), or allergic reactions. Severity graded as mild, moderate, or severe.
From intervention administration up to 24 hours postpartum.
Neonatal Apgar Score at 5 Minutes
Time Frame: At 5 minutes after birth.
Apgar score assessed at 5 minutes after birth. Score ranges from 0-10, with higher scores indicating better neonatal condition.
At 5 minutes after birth.
Neonatal Complications
Time Frame: From birth up to 48 hours, through hospital discharge.
Occurrence of neonatal complications including: Apgar score <7 at 5 minutes, meconium-stained amniotic fluid, need for neonatal resuscitation, NICU admission, or neonatal asphyxia
From birth up to 48 hours, through hospital discharge.
Pain Scores (Visual Analog Scale)
Time Frame: Pre-intervention, and at 30 minutes, 1 hour, and 2 hours post-intervention.
Maternal pain assessed using Visual Analog Scale (VAS) from 0 (no pain) to 10 (worst imaginable pain). Measured at baseline (pre-intervention), 30 minutes, 1 hour, and 2 hours post-intervention.
Pre-intervention, and at 30 minutes, 1 hour, and 2 hours post-intervention.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Subgroup Analysis by Maternal Age
Time Frame: Throughout study period, average of six months
Comparison of primary and secondary outcomes stratified by maternal age categories (<20 years, 20-35 years, >35 years).
Throughout study period, average of six months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Universidad Nacional Autonoma de Honduras

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 17, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 24, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 27, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PO-UNAH-49-7-2026

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Individual participant data (anonymized) will be shared for scientific purposes related to obstetric analgesia and labor management. Only de-identified datasets will be shared with qualified researchers upon reasonable request and with appropriate ethics committee approval. Participants will be informed of data sharing plans during the informed consent process and may opt out.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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