European Journal of Cardiovascular Medicine

Acute low back pain (LBP) is among the most frequently encountered musculoskeletal conditions in orthopaedic and primary care settings, with significant implications for quality of life and healthcare burden globally. It is characterized by sudden onset of pain lasting less than six weeks, commonly associated with muscle spasm and functional impairment. While the condition is often self-limiting, pharmacologic intervention is necessary in many cases to reduce pain, facilitate early mobilization, and prevent chronicity [4].

Muscle relaxants are widely used as adjuncts to non-steroidal anti-inflammatory drugs (NSAIDs) in the management of acute LBP, especially where muscle spasm is a predominant feature [3,4]. Tizanidine, an α2-adrenergic agonist, exerts its action centrally by reducing spasticity through inhibition of presynaptic motor neurons. It has been shown to provide effective analgesia and muscle relaxation but is often limited by side effects such as sedation and hypotension [1,7].

On the other hand, Thiocolchicoside is a semi-synthetic derivative of colchicoside that acts on GABA-A receptors. It possesses muscle relaxant, analgesic, and anti-inflammatory properties and is known for its minimal sedative effects, making it favorable for daytime use [1,3,6]. Previous studies have reported the efficacy of thiocolchicoside alone or in combination with NSAIDs in acute LBP, with varying degrees of muscle relaxation and tolerability [2,5,6].

Despite widespread use, limited comparative data exist regarding the efficacy and safety profiles of Tizanidine and Thiocolchicoside in the context of acute LBP. This study aims to evaluate and compare the therapeutic benefits and adverse effects of these two agents in orthopaedic patients, thereby guiding clinicians in making evidence-based decisions for optimal patient care.

Study Design and Setting:
This was a prospective, randomized, comparative study conducted in the Department of Orthopaedics at Government Medical College, Khammam, Telangana. The study was carried out over a period of three months, from April 2024 to June 2024.

Study Population:
A total of 100 adult patients (aged 18–65 years) presenting with acute low back pain of less than two weeks’ duration were enrolled after obtaining informed consent. Patients with a history of trauma, neurological deficits, chronic back pain, spinal infections or tumors, pregnancy, hepatic or renal impairment, and known hypersensitivity to the study drugs were excluded.

Randomization and Group Allocation: Patients were randomized into two equal groups (n = 50 each) using a computer-generated random number table:

Group A: Received Tizanidine 2 mg orally twice daily for 7 days.

Group B: Received Thiocolchicoside 4 mg orally twice daily for 7 days.

Outcome Measures:
Pain intensity was assessed using the Visual Analog Scale (VAS) at Day 0 (baseline), Day 3, and Day 7. Muscle spasm was evaluated using the Modified Ashworth Scale on Day 0 and Day 7. Adverse effects were monitored throughout the study period, and patient satisfaction was assessed on Day 7 using a 3-point Likert scale (Very satisfied, Satisfied, Neutral/Dissatisfied).

Statistical Analysis:
Data were analyzed using SPSS software version 26.0 (IBM Corp., Armonk, NY, USA). Continuous variables were expressed as mean ± standard deviation and compared using independent sample t-tests. Categorical variables were analyzed using the chi-square test. A p-value of <0.05 was considered statistically significant.

A total of 100 patients with acute low back pain were enrolled and randomized into two groups: Tizanidine (n = 50) and Thiocolchicoside (n = 50). Both groups were comparable at baseline in terms of demographic characteristics and initial pain scores.

Demographic and Baseline Characteristics

The mean age of participants in the Tizanidine group was 42.3 ± 10.2 years, while in the Thiocolchicoside group it was 41.8 ± 11.0 years (p = 0.782). The gender distribution was also similar, with 58% males in the Tizanidine group and 54% in the Thiocolchicoside group (p = 0.684). Baseline Visual Analog Scale (VAS) pain scores were comparable between the two groups (7.8 ± 1.1 vs. 7.7 ± 1.2; p = 0.742), as shown in Table 1.

Table 1: Demographic and Baseline Characteristics

Pain Intensity (VAS Score) Reduction

Both groups exhibited a reduction in pain intensity over the 7-day treatment period. However, patients in the Tizanidine group showed a statistically significant reduction in VAS scores compared to the Thiocolchicoside group at Day 3 (4.2 ± 1.0 vs. 4.6 ± 1.1; p = 0.048) and Day 7 (2.1 ± 0.9 vs. 2.7 ± 1.0; p = 0.011), indicating better analgesic efficacy of Tizanidine (Table 2).

Table 2: Comparison of Pain Scores (VAS)

Muscle Spasm Relief

Muscle spasm reduction, assessed by the Modified Ashworth Scale, was more pronounced in the Tizanidine group. At Day 7, the mean spasm score in the Tizanidine group was significantly lower than in the Thiocolchicoside group (0.8 ± 0.4 vs. 1.1 ± 0.5; p = 0.027). No significant difference was observed at baseline (p = 0.620), confirming comparability at enrollment (Table 3).

Table 3: Muscle Spasm Relief (Modified Ashworth Scale)

Adverse Events and Patient Satisfaction

Adverse effects were more frequently reported in the Tizanidine group (28%) compared to the Thiocolchicoside group (16%). Drowsiness (16%) and dry mouth (10%) were the most common complaints in the Tizanidine group, whereas gastrointestinal upset (8%) was more frequent in the Thiocolchicoside group. Despite the higher adverse event rate, patient satisfaction was higher in the Tizanidine group, with 60% reporting they were "very satisfied" compared to 46% in the Thiocolchicoside group (Table 4).

Table 4: Adverse Effects and Patient Satisfaction

The present study compared the efficacy and safety of Tizanidine and Thiocolchicoside in patients presenting with acute low back pain. Both drugs demonstrated effectiveness in reducing pain and muscle spasm, but Tizanidine was associated with significantly greater improvement in VAS scores and Modified Ashworth Scale values by Day 7. These findings are in alignment with earlier reports that support the use of muscle relaxants for rapid symptomatic relief in acute musculoskeletal conditions [9].

Thiocolchicoside has long been favored for its muscle relaxant properties and minimal sedative effects, making it suitable for ambulatory patients [6]. In our study, Thiocolchicoside was well tolerated, with fewer central nervous system-related side effects compared to Tizanidine. This corroborates previous findings from Indian and international studies that emphasized the drug’s efficacy in muscle spasm without compromising daytime alertness [6,7].

However, patients in the Tizanidine group reported significantly better pain relief and higher satisfaction scores, despite a higher incidence of drowsiness. This suggests that, for some patients, the sedative effect of Tizanidine may be acceptable when balanced against its superior muscle relaxation and analgesic effects. Similar outcomes were reported in a multicentric study comparing aceclofenac with and without Tizanidine, where the combination group experienced faster and greater symptom relief [7].

Broader literature reviews and evidence maps have also confirmed the utility of centrally acting muscle relaxants like Tizanidine in acute back pain, although they highlight the need for caution regarding side effects [8,9]. Additionally, the Cochrane review and systematic analyses have emphasized that while NSAIDs remain first-line, adjunctive therapies like muscle relaxants are essential in moderate to severe cases [11,12].

In this comparative study, Tizanidine demonstrated greater efficacy than Thiocolchicoside in relieving pain and reducing muscle spasm in patients with acute low back pain. Statistically significant improvements in VAS scores and Modified Ashworth Scale were observed in the Tizanidine group by Day 7. Although Tizanidine was associated with a higher incidence of adverse effects such as drowsiness and dry mouth, patient satisfaction was notably higher, indicating better overall symptom control. Thiocolchicoside, while effective and better tolerated in terms of sedation, showed comparatively slower and lesser improvement. Thus, Tizanidine may be preferred for rapid symptomatic relief, with Thiocolchicoside as an alternative in patients sensitive to sedatives.

1. Ketenci A, Ozcan E, Karamursel S. Assessment of efficacy and psychomotor performances of thiocolchicoside and tizanidine in patients with acute low back pain. Int J Clin Pract. 2005 Jul;59(7):764-70. doi: 10.1111/j.1742-1241.2004.00454.x. PMID: 15963201.
2. Karmakar A, Arora S, Singal R, Mitra S, Gitika, Saha M, Mitra M. The Efficacy and Safety of a Combination of Thiocolchicoside and Etoricoxib in Low Back Pain (ESCoTEL): A Randomized Active-Controlled Trial. Cureus. 2023 Oct 25;15(10):e47621. doi: 10.7759/cureus.47621. PMID: 38021944; PMCID: PMC10681115.
3. Rao R, Panghate A, Chandanwale A, Sardar I, Ghosh M, Roy M, Banerjee B, Goswami A, Kotwal PP. Clinical comparative study: efficacy and tolerability of tolperisone and thiocolchicoside in acute low back pain and spinal muscle spasticity. Asian Spine J. 2012 Jun;6(2):115-22. doi: 10.4184/asj.2012.6.2.115. Epub 2012 May 31. PMID: 22708015; PMCID: PMC3372546.
4. Hong JY, Song KS, Cho JH, Lee JH. An Updated Overview of Low Back Pain Management in Primary Care. Asian Spine J. 2017 Aug;11(4):653-660. doi: 10.4184/asj.2017.11.4.653. Epub 2017 Aug 7. PMID: 28874985; PMCID: PMC5573861.
5. Iliopoulos K, Koufaki P, Tsilikas S, Avramidis K, Tsagkalis A, Mavragani C, Zintzaras E. A randomized controlled trial evaluating the short-term efficacy of a single-administration intramuscular injection with the fixed combination of thiocolchicoside-diclofenac versus diclofenac monotherapy in patients with acute moderate-to-severe low back pain. BMC Musculoskelet Disord. 2023 Jun 10;24(1):476. doi: 10.1186/s12891-023-06599-0. PMID: 37301824; PMCID: PMC10257820.
6. Soonawalla DF, Joshi N. Efficacy of thiocolchicoside in Indian patients suffering from low back pain associated with muscle spasm. J Indian Med Assoc. 2008 May;106(5):331-5. PMID: 18839644.
7. Pareek A, Chandurkar N, Chandanwale AS, Ambade R, Gupta A, Bartakke G. Aceclofenac-tizanidine in the treatment of acute low back pain: a double-blind, double-dummy, randomized, multicentric, comparative study against aceclofenac alone. Eur Spine J. 2009 Dec;18(12):1836-42. doi: 10.1007/s00586-009-1019-4. Epub 2009 May 7. PMID: 19421791; PMCID: PMC2899439.
8. Brasure M, Nelson VA, Scheiner S, et al. Treatment for Acute Pain: An Evidence Map [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2019 Oct. (Comparative Effectiveness Reviews, No. 33.) Appendix H, Evidence Tables: Acute Back Pain. Available from: https://www.ncbi.nlm.nih.gov/books/NBK549322/
9. Chou R, Peterson K, Helfand M. Comparative efficacy and safety of skeletal muscle relaxants for spasticity and musculoskeletal conditions: a systematic review. J Pain Symptom Manage. 2004 Aug;28(2):140-75. doi: 10.1016/j.jpainsymman.2004.05.002. PMID: 15276195.
10. Hong JY, Song KS, Cho JH, Lee JH, Kim NH. An Updated Overview of Low Back Pain Management. Asian Spine J. 2022 Dec;16(6):968-982. doi: 10.31616/asj.2021.0371. Epub 2021 Dec 30. PMID: 34963043; PMCID: PMC9827206.
11. van der Gaag WH, Roelofs PD, Enthoven WT, van Tulder MW, Koes BW. Non-steroidal anti-inflammatory drugs for acute low back pain. Cochrane Database Syst Rev. 2020 Apr 16;4(4):CD013581. doi: 10.1002/14651858.CD013581. PMID: 32297973; PMCID: PMC7161726.
12. Keller A, Hayden J, Bombardier C, van Tulder M. Effect sizes of non-surgical treatments of non-specific low-back pain. Eur Spine J. 2007 Nov;16(11):1776-88. doi: 10.1007/s00586-007-0379-x. Epub 2007 Jul 10. PMID: 17619914; PMCID: PMC2223333.