Study of the efficacy and tolerability of injectable muscle relaxants with a central mechanism of action in non-specific back pain with muscle-tonic syndrome and in myofascial back pain syndrome

Abstract

The study aimed to compare the efficacy and tolerability of injectable thiocolchicoside and methocarbamol (Dorsum) in non-specific back pain with muscle-tonic syndrome and myofascial back pain syndrome. Materials and methods. A multicenter comparative study was conducted. Ninety patients with non-specific back pain with muscle-tonic syndrome or myofascial back pain syndrome were examined, who were divided into groups of 30 patients: active group 1 — methocarbamol (Dorsum), active group 2 — thiocolchicoside, group 3 (control) — NSAIDs. The dynamics of pain syndrome were evaluated by VAS; the dynamics by needle ENMG (in half of patients in each group), and tolerability (evaluated only in active groups) were also assessed. Results. After 3 days of treatment, back pain decreased: by 48.9% in the injectable methocarbamol (Dorsum) group, by 35.5 % in the injectable thiocolchicoside group, and by 16.7 % in the NSAIDs group. After 3 days of treatment, the electromyographic signs of muscle spasm according to needle ENMG data disappeared: in 80 % (12 out of 15) of patients in the injectable methocarbamol (Dorsum) group, in 53.3 % (8 out of 15) of patients in the injectable thiocolchicoside group, and in 46.7 % (7 out of 15) of patients in the NSAIDs group. In the injectable methocarbamol (Dorsum) group, no complaints of tolerability were reported; in the injectable thiocolchicoside group, 23.3 % of patients (7 out of 30) reported side effects: 10 % (3 out of 30) — drowsiness, 6.7 % (2 out of 30) — nausea, of which 3.3 % (1 out of 30) —single vomiting and 6.7 % (2 out of 30) — epigastric pain. Conclusions. Injectable methocarbamol (Dorsum) was more effective than injectable thiocolchicoside in patients with non-specific back pain with muscle-tonic syndrome or myofascial back pain syndrome and showed better tolerability.