Efficacy and Safety of Intravenous Paracetamol Compared With Intramuscular Tramadol for Labour Analgesia: A Randomised Comparative Study.

introductionLabour pain is a major source of maternal distress, particularly in settings where epidural analgesia is not routinely available. This study primarily compared the change in labour-pain intensity from baseline to one hour after intravenous paracetamol or intramuscular tramadol and secondarily compared labour, maternal safety and neonatal outcomes.

methodsThis was a prospective, single-blind, randomised controlled trial conducted in the Department of Obstetrics and Gynaecology, Nil Ratan Sircar Medical College and Hospital, Kolkata, India. A total of 11,002 healthy primigravidae aged 18-35 years in spontaneous labour were randomised to receive either intravenous paracetamol 1 g (n = 5,499) or intramuscular tramadol 100 mg (n = 5,503). Pain intensity was assessed using the Visual Analogue Scale before drug administration and at 10 minutes and one hour after administration. Labour duration, mode of delivery, maternal adverse events, and neonatal outcomes were recorded. Analyses were performed using both per-protocol (n = 9,945) and intention-to-treat approaches. Relative risks with 95% confidence intervals were calculated where appropriate.

resultsBoth intravenous paracetamol and intramuscular tramadol significantly reduced labour pain. Tramadol produced slightly lower Visual Analogue Scale scores at 10 minutes and one hour, indicating marginally greater analgesic efficacy. However, tramadol was associated with higher maternal adverse effects, including nausea (35.3% vs 26.7%), vomiting (23% vs 10%), and decreased respiratory rate (6% vs 3%). Neonatal outcomes were also less favourable in the tramadol group, with higher rates of neonatal intensive care unit admission (12% vs 6%), depressed neonatal respiration (20% vs 7%), and lower Apgar scores (p < 0.0001). Intention-to-treat analysis confirmed the direction and magnitude of these findings, supporting the robustness of the results.

conclusionBoth intravenous paracetamol and intramuscular tramadol reduced labour-pain scores. Tramadol was associated with a small additional short-term reduction in pain, whereas intravenous paracetamol was associated with fewer maternal adverse effects and more favourable reported neonatal outcomes. Intravenous paracetamol may therefore represent a useful and better-tolerated non-opioid alternative where neuraxial analgesia is unavailable or unsuitable. However, the findings should be interpreted cautiously because of the single-centre design, incomplete blinding and post-randomisation exclusions and should not be considered definitive practice-changing evidence.