Oral vs. IV paracetamol for pain control in patients with femur fracture in the emergency department: a practical randomized controlled trial

Femur fracture (FF) is a common reason for admission to the Emergency Department (ED) and pain is a frequent symptom. Effective and timely pain control is essential for these patients, however, the most appropriate analgesic therapy for quick pain relief in the ED setting is not well established. This is a single-center pragmatic randomized controlled study. We have enrolled 171 consecutive patients with FF and severe pain. They were randomized 1:5 to receive treatment with paracetamol 1000 mg orally (OR) or with paracetamol 1000 mg intravenously (IV). The effect on pain relief was measured with the Visual Analogue Scale for Pain (VAS) at baseline (T0), after 1 hour (T1), 2 hours (T2), and 4 hours (T4). The primary endpoint was the reduction of pain of 1 point of the VAS at T1. This target was reached by 75% of patients treated with paracetamol IV and 44% treated with paracetamol OR (p = 0.001). The secondary endpoint was the reduction of pain of at least 2 points of the VAS at T4, the need for rescue therapy, and the number of adverse events. At T4 the efficacy of paracetamol IV and OR resulted in 89.5% and 88.9%, respectively (p = 0.914). The 17.5% of patients treated with paracetamol IV vs. the 3.7% treated with paracetamol OR required rescue therapy (p = 0.082), with prevalence among women (p = 0.057). No adverse effects were reported. The treatment with paracetamol 1000 mg IV and OR resulted effective and safe for patients with FF waiting for surgery. IV administration was faster in reducing pain in the first 2 hours compared to oral administration but the latter required less rescue therapy. Interestingly, our study highlighted gender differences in pain relief opening the way for a gender-tailored therapy.