NSAIDs in sciatica (NIS): study protocol for an investigator-initiated multicentre, randomized placebo-controlled trial of naproxen in patients with sciatica

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to treat sciatica, despite insufficient evidence from placebo-controlled trials. NSAIDs may cause serious side effects; hence, there is a strong need to clarify their potential beneficial effects in patients with sciatica. Methods: This is a multicentre, randomized, placebo-controlled, parallel-group superiority trial. Participants will be recruited among sciatica patients referred to outpatient clinics at hospitals in Norway who have radiating pain below the knee with a severity score of >= 4 on a 0-10 numeric rating scale and clinical signs of nerve root or spinal nerve involvement. The intervention consists of oral naproxen 500 mg or placebo twice daily for 10 days. Participants will report the outcomes and adverse events daily using an electronic case report form. The primary endpoint is change in leg pain intensity from baseline to day 10 based on daily observations. The secondary outcomes are back pain intensity, disability, sciatica symptom severity, rescue medication (paracetamol) consumption, opioid use, ability to work or study, 30% and 50% improvement in leg pain, and global perceived change of sciatica/back problem. The outcomes will be analysed using mixed effects models for repeated measurements. The total duration of follow-up is 12 (+/- 2) days. Discussion: This trial aims to evaluate the benefits of naproxen, a non-selective NSAID, in patients with sciatica. No important differences in efficacy have been demonstrated between different NSAIDs in the management of musculoskeletal disorders; hence, the results of this trial will likely be applicable to other NSAIDs.