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

NCT07440069 | Recruiting Phase 4 DMC

• 1 other identifier: PO-UNAH-49-7-2026
• Study Type: interventional
• Target: 300
• Locations: 1 country
• Sites: 2

Brief Summary

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.

Conditions

Labor Pain

Keywords

Tramadol; Paracetamol; Acetaminophen; Labor Pain; Labor Duration

Outcome Measures

Primary Outcomes (1)

• Duration of Active Labor

  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 Outcomes (7)

• Duration of Expulsive Phase (Second Stage)

  During delivery, from complete cervical dilation up to 120 minutes.

• Type of Delivery

  At delivery

• Need for Oxytocin Augmentation

  During labor (from intervention administration up to 24 hours).

• Maternal Adverse Events

  From intervention administration up to 24 hours postpartum.

• Neonatal Apgar Score at 5 Minutes

  At 5 minutes after birth.

Other Outcomes (1)

• Subgroup Analysis by Maternal Age

  Throughout study period, average of six months

Study Arms (3)

Tramadol Group

EXPERIMENTAL

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

Paracetamol Group

EXPERIMENTAL

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)

Placebo Group

PLACEBO COMPARATOR

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)

Interventions

Tramadol Hydrochloride DRUG

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.

Tramadol Group

Paracetamol (acetaminophen) DRUG

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).

Paracetamol Group

Placebo (Saline Solution) DRUG

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.

Placebo Group

Eligibility Criteria

• Age: 15 Years - 45 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Universidad Nacional Autonoma de Honduras: lead

Study Sites (2)

Hospital Escuela

Tegucigalpa, Francisco Morazán Department, 11101, Honduras

RECRUITING

Instituto Hondureño de Seguridad Social

Tegucigalpa, Francisco Morazán Department, 11101, Honduras

RECRUITING

Related Publications (1)

• Usman M, Ashraf M, Khokhar MI, Ashiq B, Masood MI, Afzal S, Omer O, Ali M, Qadir MI. Comparative pharmacokinetics of levofloxacin in healthy volunteers and in patients suffering from typhoid Fever. Iran J Pharm Res. 2013 Winter;12(1):147-54.

  PMID: 24250583 BACKGROUND

MeSH Terms

Conditions

Labor Pain

Interventions

Tramadol; Acetaminophen; Saline Solution

Condition Hierarchy (Ancestors)

Pain; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Cyclohexanols; Hexanols; Fatty Alcohols; Alcohols; Organic Chemicals; Dimethylamines; Methylamines; Amines; Lipids; Acetanilides; Anilides; Amides; Aniline Compounds; Crystalloid Solutions; Isotonic Solutions; Solutions; Pharmaceutical Preparations

Central Study Contacts

Ricardo A. Gutierrez-Ramirez, MD, MSc

CONTACT

+50497546940; ricardo.gutierrez@unah.edu.hn

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Coordinator

Study Record Dates

• First Submitted: February 17, 2026
• First Posted: February 27, 2026
• Study Start: February 15, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: February 27, 2026

Record last verified: 2026-02

Locations

HO (2)