[Open observational study with a retrospective analysis of the efficacy and tolerability of aceclofenac in patients with acute non-specific low back pain].

Objective: To analyze the efficacy and tolerability of aceclofenac in the treatment of patients with acute non-specific musculoskeletal pain in the lower back (ANBP) compared with other NSAIDs (dexketoprofen, nimesulide and lornoxicam), as well as to assess the impact of NSAIDs therapy on the relative risk of recurrence and chronicity of this pathology.

Material And Methods: The study involved 80 patients (47 women and 33 men), average age 52.6 [47.2; 56.9] years, divided into 4 groups: group 1 (20) aceclofenac 200 mg/day 10 days; group 2 (20) dexketoprofen 50 mg/day 5 days; group 3 (20) nimesulide 200 mg/day 10 days; group 4 (20) lornoxicam 16 mg/day 10 days. All patients received basic treatment, including an oral centrally acting muscle relaxant for 14 days and B vitamins for 1 month. Within the framework of 3 visits (start of treatment, 14 days and 1 month) the VAS pain scale, the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), the Back Pain Functional Scale (BPFS), the SF-36 «The Medical Outcomes Study 36-Item Short-Form Health Survey», the Global Rating of Change Scale (GROC), adverse drug reactions were analyzed. The probability of relapse and chronicity of pain syndrome after NSAID treatment was retrospectively assessed in 251 patients: aceclofenac (54), dexketoprofen (62), nimesulide (74) and lornoxicam (61). The duration of the observation period was 20.2±3.5 months.

Results: In visits 2 and 3 there was a significant relief of pain (VAS) and the neuropathic component of pain (LANSS) compared to the initial parameters without significant differences between the groups. At visit 2 and visit 3 in group 4 the BPFS and SF-36 values were significantly lower than in the other groups. In group 2 at visit 2 the SF-36 was significantly lower than in groups 1 and 2. The total number of adverse events was 41.3%. A higher frequency of gastrointestinal adverse events was observed in group 2, and cardiovascular - in group 4 compared to the group 1. At the end of the study, a significantly larger proportion of patients in all groups of patients assessed the improvement from the therapy as «significant», without any differences between the groups. The relative risk of low back pain chronicity was significantly higher with nimesulide (OR=4.378 (0.95% CI 1.022-18.765)) and lornoxicam (OR=4.426 (0.95% CI (1.014-19.316)), and recurrence was higher with dexketoprofen (OR=2.743 (0.95% CI 1.076 - 6.994)) compared to aceclofenac.

Conclusions: The use of NSAIDs for low back pain is effective and safe. Aceclofenac and nimesulide are superior to dexketoprofen and lornoxicam in terms of functional activity associated with low back pain and health-related quality of life. Aceclofenac demonstrated the most favorable safety profile and a lower risk of chronicity (compared to nimesulide and lornoxicam) and recurrence (compared to dexketoprofen) of low back pain.