Factors influencing the efficacy of nonsteroidal anti-inflammatory drugs for acute low back pain. The results of the multicenter observational «CARAMBOL» (Clinical Analysis of Results of Analgesia by Meloxicam and its Safety in Acute Lumbodynia) study

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a main tool to treat acute nonspecific low back pain (NLBP). However, no factors that influence the efficacy of these drugs have been identified to the present day. Objective : to evaluate the therapeutic effect of and tolerance to NSAIDs (meloxicam) in treating acute NLBS and to identify the factors influencing the efficacy of this drug. Patients and methods . A study group consisted of 2078 patients (mean age 46.3±13.4 years; women 56.6%) with acute NLBS who had been treated in real clinical practice. The level of pain was estimated using a 0–10 point numerical rating scale (NRS). Initially, the pain level averaged 6.69±1.65 scores; 57.0% of patients were noted to have severe pain (≥7 NRS scores). Pain at rest persisted in 32.0% of patients; that at night was in 19.0%; sensation of stiffness in 60.7%, irradiation to the leg in 28.2%, and lumbar ischialgia in 9.6%. 70.2% of patients had been previously treated with NSAIDs for NLBS, while only 28.0% rated their efficacy as good. All the patients were prescribed meloxicam at a dose of 15 mg/day for a period of up to 2 weeks. 86.1% of the patients received meloxicam intramuscular for 2 days, then orally; 13.9% took the drug only orally. 52.3% of the patients also used muscle relaxants; 17.4% received oral or intramuscular B vitamins. The study estimated the rate of complete pain relief when NSAIDs were used for up to 2 weeks. Results and discussion . Complete pain relief was achieved in 75.2% of patients. 83.7% of patients rated the effect of treatment as good or excellent. Undesired drug reactions were recorded in 4.6% of patients. Female gender had no effect on treatment outcome (odds ratio (OR)=0.967; 95% confidence interval (CI), 0.795–1.177; p=0.763). Age over 65 years, the first NLBS episode, and a good NSAID effect in a history were associated with the best treatment result: OR=2.053 (95% CI, 1.5920–2.642), p<0.001; 1.415 (1.09–1.836), p=0.009; and 1.937 (1.513–2.481), p<0.001, respectively. Severe pain (≥7 NRS scores), persistent pain at rest and at night, and especially lumbar ischialgia indicated the worst result: OR=0.481 (95% CI, 0.393–0.588), p<0.001; 0.559 (0.441–0.709), p<0.001; 0.511 (0.413–0.631), p<0.001; and 0.346 (0.256–0.466), p<0.001, respectively. NSAIDs in combination with muscle relaxants and B vitamins versus NSAID monotherapy did not increase the likelihood of pain relief: OR=0.827 (95% CI, 0.594–0.889), p=0.02 and 0.917 (0.804–1.1201), p=0.452, respectively. Conclusion . Meloxicam at a dose of 15 mg/day is an effective and safe drug to treat acute NLBS. Patient gender has no effect on treatment outcome. Age over 65 years, the first NLBS episode, and a good response to NSAIDs in a history are associated with the best treatment results; and severe pain, persistent pain at rest and at night, irradiation to the leg, and lumbar ischialgia are related to the worst result. NSAIDs in combination with muscle relaxants and B vitamins did not improve treatment outcomes.