Efficacy and safety of loxoprofen sodium topical patch for the treatment of pain in patients with minor acute traumatic limb injuries in Brazil: a randomized, double-blind, noninferiority trial

Abstract Posttraumatic injury pain is commonly treated with oral nonsteroidal anti-inflammatory drugs. However, oral nonsteroidal anti-inflammatory drugs cause several adverse events, with topical formulations arising as an important alternative. Therefore, we aimed at evaluating the efficacy and safety of loxoprofen patch (LX-P) in the treatment of patients with posttraumatic pain. This phase III, randomized, double-blind, noninferiority study enrolled Brazilian patients aged 18 to 65 years diagnosed with lower and upper limb posttraumatic injury who were experiencing moderate or severe pain. Patients were assigned to active LX-P or to loxoprofen tablet (LX-T), and pain intensity was measured based on a visual analog scale score variation after 7 days of treatment. Data on clinical symptoms, rescue medication use, and adverse events were also collected. Visual analog scale score variation was compared using a 10% noninferiority margin. Two hundred forty-two patients were randomly assigned to LX-P (n = 123) or to LX-T (n = 119). The results showed a reduction in pain after 7 days of treatment: −49.96 (n = 118; SE 1.7) in the LX-P and −47.71 (n = 117; SE 1.6) in the LX-T groups (difference of −2.25; 95% CI: −5.97 to 1.47; P = 0.23). On the safety analysis, the LX-T group presented twice as many patients with treatment-emergent adverse events as the LX-P group (30.8% and 14.2%, respectively). A sensitivity analysis demonstrated that rescue medication use has not affected the primary end point. This study showed that LX-P has a comparable efficacy to LX-T, but with a better safety profile, being a therapeutic option for the treatment of posttraumatic injury pain.