RecruitingPhase 4NCT07440069

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

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

Sponsor

Universidad Nacional Autonoma de Honduras

Enrollment

300 participants

Start Date

Feb 15, 2026

Study Type

INTERVENTIONAL

Conditions

Labor Pain

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.

Eligibility

Sex: FEMALEMin Age: 15 YearsMax Age: 45 Years

Inclusion Criteria6

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 Criteria9

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

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Interventions

DRUGTramadol 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.

DRUGParacetamol (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).

DRUGPlacebo (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.