Evaluation of sedative effects of single and repeated doses of 50 mg and 150 mg tolperisone hydrochloride. Results of a prospective, randomized, double-blind, placebo-controlled trial

RESUME-1: a Phase III study of tolperisone in the treatment of painful, acute muscle spasms of the back

Tolperisone is a nonopioid, centrally acting muscle relaxant in clinical development in the USA for the treatment of symptoms associated with acute, painful muscles spasms of the back. CLN-301, RESUME-1, is a 14-day double-blind, randomized, placebo-controlled, parallel-group Phase III study of the efficacy and safety of tolperisone administered orally three-times daily in 1000 male and female subjects at approximately 70 clinical sites in the USA experiencing back pain due to or associated with muscle spasm of acute onset. Tolperisone is a promising therapeutic for managing acute, painful muscle spasms of the back as it appears to lack the off-target CNS effects often seen with conventional skeletal muscle relaxants. Clinical Trials Registration: NCT04671082.

Tolperisone for the Treatment of Acute Muscle Spasm of the Back: Results from the Dose-Ranging Phase 2 STAR Study (NCT03802565)

Objective

Use of skeletal muscle relaxants (SMRs) for acute muscle spasm is confounded by central nervous system adverse events (AEs), including somnolence. Tolperisone is an SMR that does not appear to be associated with somnolence. The aim of this study was to assess the safety and efficacy of tolperisone versus placebo in subjects with acute muscle spasm of the back.

Methods

STAR (NCT03802565) was a double-blind, randomized, placebo-controlled phase 2 study in subjects with back pain due to acute muscle spasm. Subjects were randomized 1:1:1:1:1 to tolperisone 50, 100, 150, or 200 mg three times daily (TID) or placebo for 14 days. The primary efficacy endpoint was subject-rated pain "right now" using a numeric rating scale on day 14.

Results

Subjects (tolperisone, n=337; placebo, n=78) were enrolled at 38 US clinical sites. Tolperisone was well tolerated, with AEs in 18.1% of subjects receiving tolperisone versus 14.1% of subjects receiving placebo. Headache (7.1%) and diarrhea (2.4%) were the most frequent AEs in tolperisone-treated subjects versus 3.8% and 0%, respectively, in placebo-treated subjects. Somnolence was reported in 1.2% and 2.6% of subjects treated with tolperisone and placebo, respectively. Mean change from baseline in numeric rating scale score of pain "right now" on day 14 was -3.5 for placebo versus -4.2, -4.0, -3.7, and -4.4 for tolperisone 50, 100, 150, and 200 mg TID, respectively (linear test of trend on the least-squares mean difference [treatment-placebo]; p=0.0539). In an analysis of pairwise estimates (treatment-placebo), the greatest numerical difference and significance were observed for tolperisone 200 mg TID (p=0.0040). Several secondary endpoints trended toward significance for tolperisone 200 mg TID versus placebo.

Conclusion

Tolperisone 200 mg TID may be a promising treatment for acute muscle spasm, without the somnolence associated with SMRs. The safety and efficacy of tolperisone should be evaluated in a phase 3 trial.

An assessment of the centrally acting muscle relaxant tolperisone on driving ability and cognitive effects compared to placebo and cyclobenzaprine

WHAT IS KNOWN AND OBJECTIVE

Tolperisone is a centrally acting muscle relaxant under development in the United States as a treatment for acute and painful symptoms of muscle spasms. The objective of this three-way, randomized, blinded, three-period crossover study was to assess the safety and cognitive effects of tolperisone compared to placebo and the widely used muscle relaxant cyclobenzaprine in healthy volunteers.

METHODS

Subjects were randomized to 1 of 3 treatment arms to receive tolperisone (150 mg), cyclobenzaprine (10 mg) or placebo 3 times per day (TID) in 3 separate study periods. Subjects completed a driving test on the Cognitive Research Corporation's Driving Simulator (CRCDS Mini-Sim), a validated driving simulator, on day 1 at time to maximum plasma concentration, on day 2 before the morning dose of study drug and on day 3 at steady state following the morning dose. Subjects were assessed on various driving parameters and on a computer-administered digit-symbol substitution test (CogScreen symbol digit coding test). The driving scenario is a monotonous 100 km highway route on which subjects are instructed to maintain speed and lane position.

RESULTS AND DISCUSSION

The performance of subjects who had received tolperisone was not significantly different from those who had received placebo in terms of the primary end point: standard deviation of lateral position, a measure of weaving. Subjects who had received tolperisone also performed comparably to those who had received placebo on a range of secondary measures assessing driving ability, cognition and psychomotor performance. In contrast, subjects who had received cyclobenzaprine showed significant impairment compared to placebo (P < .01) on the primary end point of standard deviation of lateral position and on the majority of the secondary end points of driving ability. Despite their markedly poorer driving performance after receiving cyclobenzaprine, few subjects reported feeling unsafe to drive on day 1 (10.3%) and day 2 (3.4%). The incidence of adverse events was similar for tolperisone (36.4%) and placebo (29.0%) and was greater for cyclobenzaprine (45.4%).

WHAT IS NEW AND CONCLUSION

Subjects who received tolperisone (150 mg TID) experienced no impact on various measures of driving, self-reported sleepiness and cognition measures compared to placebo, in contrast to those who received the widely used muscle relaxant cyclobenzaprine (10 mg TID).

[Results of a randomized double blind parallel study on the efficacy and safety of tolpersione in patients with acute nonspecific low back pain]

AIM

To evaluate the efficacy and safety of tolpersione injection and oral formulations combined with NSAID over NSAID monotherapy in acute non-specific low back pain.

MATERIAL AND METHODS

In this randomized double blind study 239 patients were included in the per protocol analysis. The first 5 days of treatment, patients received tolpersione or placebo injection which was followed by per os administration of tolpersione/placebo tablet up to 14 days. NSAID diclofenac tablet was used in both groups through the study. Functionality assessed by the Roland Morris Disability Questionnaire (RMDQ) at day 5 was the primary endpoint. Secondary endpoints were RMDQ at other time points, pain level change at rest and on movement assessed by the Visual Analogue Scale (VAS), the Clinical Global Impression of Improvement/Patient Global Impression of Improvement (CGI-I and PGI-I), change in the range of motion assessed by the distance from the fingertips to the floor, period of disability days, relative (%) changes in the daily dose of diclofenac from the 7th to the 14th day of therapy.

RESULTS AND CONCLUSION

The primary and secondary endpoints clearly demonstrated the significant superiority of tolpersione added to NSAID monotherapy over NSAID monotherapy. The safety assessment revealed no statistically significant differences between the two groups. Based on the results, tolpersione injection and per os formulations can be considered an effective and safe drugs in the combined therapy for patients with acute nonspecific back pain.

The comparative study of clinical efficacy and safety of baclofen vs tolperisone in spasticity caused by spinal cord injury

In the present study we compared the clinical efficacy and safety of baclofen vs tolperisone in spasticity caused by spinal cord injury. A total of 150 patients were enrolled in the present study and were divided into two groups with 75 patients in each group, receiving baclofen or tolperisone, respectively. We used Modified Ashworth Scale, Medical research council scale, Barthel Index, and Coefficient of efficacy to measure clinical efficacy. After 6-week treatment, both groups demonstrated significant improvement in muscle tone, muscle strength and functional outcome (Group I, 1.55 ± 0.053, 2.79 ± 0.032, 59.31 ± 1.32; Group II, 1.57 ± 0.053, 3.04 ± 0.032, 73 ± 1.32 respectively). There was no significant difference regarding improvement in muscle tone and muscle strength between the two groups (Group I, 1.055 ± 0.053 vs Group II, 1.57 ± 0.053; Group I, 2.79 ± 0.032 vs Group II, 3.04 ± 0.032, p > 0.05). However, the improvement in functional outcomes was greater in group II as compared to that in group I (Group I, 59.31 ± 1.32 vs Group II, 73 ± 1.32, p < 0.05). In addition, overall efficacy coefficient was greater for group II as compared to group I (Group I, 3.6 vs Group II, 2.3, p < 0.05). Group I had more side effects compared to Group II. Compared to baclofen, tolperisone offers greater improvement in activities of daily living compared to baclofen.

Comparative study of therapeutic response to baclofen vs tolperisone in spasticity

BACKGROUND

Spasticity from the upper motor neuron syndrome can result from a variety of conditions affecting the cortex or spinal cord. Some of the more common conditions associated with spasticity include spinal cord injury, cerebral palsy, and post-stroke syndrome. In this study we compared the efficacy and safety of baclofen vs tolperisone in spasticity. One hundred fifty patients with cerebral palsy or post stroke or spinal cord injury associated spasticity were enrolled in present study. Group I comprised of Seventy-five patients receiving baclofen and group II comprised of 75 patients receiving tolperisone. For efficacy measurement 4 evaluation methods were used, 1) Modified Ashworth Scale for muscle tone, 2) Medical research council scale for muscle strength and 3) Barthel Index for functional outcome 4) Coefficient of efficacy. In efficacy evaluation, both groups showed significant improvement in muscle tone, muscle strength and functional outcome at week 6 (Group I, 1.55±0.053, 2.79+0.032, 59.31±1.32; Group II, 1.57±0.053, 3.04±0.032, 73±1.32 respectively). In between the group analysis, there was no significant difference in muscle tone improvement in both the groups after 6 weeks (Group I, 1.055±0.053 vs Group II, 1.57±0.053, p>0.05). Group II showed non-significant but greater improvement in muscle strength (Week 6; Group I, 2.79±0.032 vs Group II, 3.04±0.032, p>0.07). Improvement in functional outcomes was greater in group II as compared to group I (Group I, 59.31±1.32 vs Group II, 73±1.32, p<0.05). Overall efficacy coefficient was greater for group II (3.6) as compared to group I (2.3). Baclofen showed more side effects compared to tolperisone in, asthenia being the most frequent. Tolperisone offers greater improvement in activities of daily living compared to baclofen. Tolperisone is more tolerable drug as compared to baclofen.

[A clinical efficacy of electrode pharmaphoresis in treatment of railway workers with low-back pain]

OBJECTIVE

To evaluate clinical efficacy and tolerability of electrode pharmaphoresis using preparations xefocam and mydocalm-richter in railway workers with low-back pain.

MATERIAL AND METHODS

Authors carried out an open prospective noncomparative study of 16 patients, aged 21-82 years, with spinal osteochondrosis with root syndrome and radiculopathia of the lumbar/sacral spine with pain syndrome regardless of its duration. Treatment efficacy was assessed by the dynamics of pain syndrome severity based on the scores of a self-rated scale completed by the patient and the McGill Pain Questionnaire. Quality-of-life was assessed with the Oswestry Disability Index before and in the end of treatment. Clinical outcome was evaluated with the modified Nurick scale. Electrode pharmaphoresis (the "Farma T.E.B. Trans Epidermal Barrier Physio" apparatus) was administered to all patients using xefocam (solution for injections 8 mg, 2 ml per procedure) and mydocalm-richter (solution for injections 100 mg, 2 ml per injection) in the lumbar/sacral spine.

RESULTS AND CONCLUSION

The high clinical efficacy of electrode pharmaphoresis using xefocam and mydocalm-richter was shown. The complex restoration study resulted in the reduction of pain syndrome in all patients. Pain severity was reduced to mild grade in 68.8% to the middle of treatment and in 93.8% patients in the end of treatment. As a consequence of pain reduction, the functional activity (quality of self-service, daily activities) increased significantly in 68.8% of patients. Positive treatment effect was noted in 100% of patients, good tolerability of this medication in 87.5%.

Basic aspects of the pharmacodynamics of tolperisone, a widely applicable centrally acting muscle relaxant

Tolperisone (2-methyl-1-(4-methylphenyl)-3-piperidin-1-ylpropan-1-one hydro-chloride) was introduced in the clinical practice more than forty years ago and is still evaluated as a widely applicable compound in pathologically elevated skeletal muscle tone (spasticity) and related pains of different origin. In the present review, basic pharmacodynamic effects measured on whole animals, analyses of its actions on cell and tissue preparations and molecular mechanism of action on sodium and calcium channels are summarized as recently significantly new data were reported.

Effect of tolperisone on the resting brain and on evoked responses, an phMRI BOLD study

Tolperisone is a voltage gated sodium channel blocker, centrally acting muscle relaxant drug, with a very advantageous side effect profile. Like other sodium channel blockers, it has weak affinity to the resting state and high affinity to the open/inactivated state of the channel. In this paper, its effect on BOLD responses in rat brain were elucidated both on the resting brain and paw stimulation evoked BOLD responses. Tolperisone did not exert any visible effect on resting brain, but strongly inhibited the paw stimulation evoked BOLD responses, showing somewhat higher efficacy in brain areas involved in pain sensation. This finding is in a good agreement with its sodium channel blocking profile. In the resting brain, most of the channels are in resting state. Electric train stimuli of the paw results in over activated neurons, where most sodium channels are in open or inactivated state. These data suggest that the very advantageous profile of tolperisone can be explained by its selective action on open or inactivated sodium channels of over-activated neurons in various brain regions rather than by a selective effect in the spinal cord as suggested previously.

Enantioselective separation and simultaneous determination of tolperisone and eperisone in rat plasma by LC-MS/MS

Tolperisone and eperisone used as muscle relaxants possess one chiral center each and exist as two optical isomers for each drug. Therefore, enantioselective assays to measure each enantiomer in biological matrices are of great importance. In the present study a simple and complete reverse-phase liquid chromatography tandem mass spectrometric method for separation and enantioselective determination of tolperisone and eperisone in rat plasma was developed. The analytes were extracted from rat plasma by a simple protein precipitation method with acetonitrile as the extraction solvent. The enantioselective separation of analytes was achieved on a Cellulose Tris (4-chloro-3-methylphenylcarbamate) chiral column with a mobile phase of acetonitrile: 10 mM ammonium acetate in an isocratic mode of elution and mass spectrometric detection. The calibration curve for each enantiomer was found to be linear over 0.2 to 20 ng/mL for each enantiomer. The proposed method exhibited good intra- and interday precision (% CV) ranged between 0.95-6.05% and 1.11-8.21%, respectively. The intra- and interday accuracy for the proposed assay method ranged between 94.0-100.5% and 92.7-102.1%, respectively. The proposed method was validated as per regulatory guidelines.

Clinical comparative study: efficacy and tolerability of tolperisone and thiocolchicoside in acute low back pain and spinal muscle spasticity

Study Design

We performed a multicentric, randomized, comparative clinical trial. Eligible patients were randomly assigned to receive 150 mg of Tolperisone thrice daily or 8 mg of Thiocolchicoside twice daily for 7 days.

Purpose

To assess the efficacy and tolerability of Tolperisone in comparison with Thiocolchicoside in the treatment of acute low back pain with spasm of spinal muscles.

Overview of Literature

No head on clinical trial of Tolperisone with Thiocolchicoside is available and so this study is done.

Methods

The assessment of muscle spasm was made by measuring the finger-to-floor distance (FFD), articular excursion in degrees on performing Lasegue's maneuver and modified Schober's test. Assessment of pain on movement and spontaneous pain (pain at rest) of the lumbar spine was made with the help of visual analogue scale score.

Results

The improvement in articular excursion on Lasegue's maneuver was significantly greater on day 3 (p = 0.017) and day 7 (p = 0.0001) with Tolperisone as compared to Thiocolchicoside. The reduction in FFD score was greater on day 7 (p = 0.0001) with Tolperisone. However there was no significant difference in improvement in Schober's test score on day 3 (p = 0.664) and day 7 (p = 0.192). The improvement in pain score at rest and on movement was significantly greater with Tolperisone (^p = 0.0001).

Conclusions

Tolperisone is an effective and well tolerated option for treatment of patients with skeletal muscle spasm associated with pain.

Effectiveness of Tolperisone Hydrochloride with Aceclofenac as Combined Therapy in Acute Low Back Pain

Objective

An open label, non-randomised, prospective study was conducted to evaluate the effectiveness of tolperisone hydrochloride 150mg thrice daily with aceclofenac 100mg twice daily compared to aceclofenac 100mg twice daily alone for the treatment of acute low back pain (LBP) for 14 days. total (n=242) patients recruited for the study were divided into two treatment groups. One of the group (n=124) received oral tolperisone plus aceclofenac and the other (n=118) Aceclofenac alone. The pain intensity was assessed by visual analogue scale. Patients were informed to report any adverse effect encountered during the study period. The overall effect of the drug (global assessment of the study medication) on pain and adverse effects were assessed by the patients at the end of the trial on a categorical scale. There was significant reduction in pain score in the tolperisone group than aceclofenac group with insignificant adverse effects which didn't require discontinuation of the study. Tolperisone when added with aceclofenac can be more effective than aceclofenac alone for relief of acute LBP with minimum adverse effects.

Tolperisone: a typical representative of a class of centrally acting muscle relaxants with less sedative side effects

Tolperisone, a piperidine derivative, is assigned to the group of centrally acting muscle relaxants and has been in clinical use now for decades. The review summarizes the known pharmacokinetics, pharmacodynamics, toxicology and side effects in humans and the clinical use of tolperisone. A future perspective for further exploration of this drug is given.

Choice of delta: requirements and reality--results of a systematic review

An essential problem in planning clinical non-inferiority or equivalence studies is the specification of the 'irrelevant difference' (irrelevance margin; delta). This quantifies the amount of non-inferiority or difference, respectively, between a new test therapy and an established standard treatment which is to be considered as tolerable. In the past, most recommendations and guidelines for clinical non-inferiority and equivalence studies contained only general statements and formulations concerning the specification of delta. The current unsatisfactory situation was the reason for performing a systematic review of published clinical non-inferiority and equivalence studies. It was the aim to gain an overview on the irrelevance margins used in such studies, and on reasons for choosing the particular margins. For the sake of comparability, the irrelevance margins were converted into standardized differences and odds ratios. Overall, there were 332 non-inferiority or equivalence trials obtained by means of an extensive literature search. The results of the systematic review show that current requirements on the choice of delta and the reality of recent clinical non-inferiority and equivalence trials differ substantially. In about one half of the trials a difference of 0.5 standard deviations or more was regarded as 'irrelevant' explicitly or implicitly. Estimates of standard-placebo differences formed the basis of the irrelevance margin in less than every tenth trial. Reasons for this very low proportion might be (1) the possibly resulting very small irrelevance margins, and (2) unsolved problems of the requirements themselves. Overall, it seems that a more global definition of 'irrelevance' might be warranted.

A randomized, double-blind, placebo-controlled study of the efficacy and safety of tolperisone in spasticity following cerebral stroke

To study the efficacy and safety of tolperisone - a centrally acting muscle relaxant with membrane stabilizing activity - in the treatment of stroke-related spasticity. This was a randomized, double-blind, placebo-controlled, multicenter study with parallel groups. Treatment lasted 12 weeks and was started with a titration period of variable length (dose range 300-900 mg tolperisone daily). The degree of spasticity determined on the Ashworth Scale in the most severely affected joint area was defined as primary target parameter. Hundred and twenty patients (43 females, 77 males) in a mean age of 63.3 +/- 10.6 years were recruited and received treatment. In the majority of patients both limbs of each side (right: n = 59; left: n = 56) were affected by the spasticity which on average had been present for 3.3 +/- 4.4 years. A 62% of the patients were treated with a daily dose >/=600 mg tolperisone. Tolperisone reduced the mean Ashworth Score by a mean of 1.03 +/- 0.71 compared with a mean reduction of 0.47 +/- 0.54 in the placebo group (P < 0.0001). A 78.3% of the patients on tolperisone versus 45% of the placebo patients experienced a reduction by at least 1 point on the Ashworth Scale (P < 0.0001). Functional and overall assessments of efficacy confirmed superior efficacy of tolperisone. Adverse events occurred less often on active treatment (n = 19) than on placebo (n = 26) and were mostly of mild-to-moderate intensity. No withdrawals caused by adverse events were reported in the tolperisone group. The findings of the present study demonstrate the efficacy and excellent tolerance of tolperisone in the treatment of spastic hypertonia following cerebral stroke. Study data further suggest that an individual dose titration which may exceed the recommended maximum dose of 450 mg daily results in optimized therapeutic benefit.

Prophylactic tolperisone for post-exercise muscle soreness causes reduced isometric force--a double-blind randomized crossover control study

The role of tolperisone hydrochloride, a centrally acting muscle relaxant in relieving painful muscle spasm is recently being discussed. The present study hypothesizes that the prophylactic use of tolperisone hydrochloride may effectively relieve post-exercise muscle soreness, based on the spasm theory of exercise pain. Twenty male volunteers, aged 25.2 +/- 0.82 years (mean +/- SEM) participated in 10 sessions in which they received oral treatment with placebo or the centrally acting muscle relaxant tolperisone hydrochloride (150 mg) three times daily for 8 days, in randomized crossover double-blind design. Time course assessments were made for pressure pain threshold, Likert's pain score (0-5), pain areas, range of abduction, isometric force, and electromyography (EMG) root mean square (RMS) during maximum voluntary isometric force on day 1 and 6, immediately after an eccentric exercise of first dorsal interosseous muscle, and 24 and 48 h after the exercise. Treatment with placebo or tolperisone hydrochloride was initiated immediately after the assessments on the first day baseline assessments. On the sixth day baseline investigations were repeated and then the subjects performed six bouts of standardized intense eccentric exercise of first dorsal interosseous muscle for provocation of post-exercise muscle soreness (PEMS). Perceived intensity of warmth, tiredness, soreness and pain during the exercise bouts were recorded on a 10 cm visual analogue pain scale. VAS scores and pressure pain thresholds did not differ between tolperisone and placebo treatment. All VAS scores increased during the exercise bouts 2, 3, 4, 5 and 6 as compared to bout 1. Increased pain scores and pain areas were reported immediately after, 24 and 48 h after exercise. Pressure pain thresholds were reduced at 24 and 48 h after the exercise in the exercised hand. Range of abduction of the index finger was reduced immediately after the exercise and was still reduced at 24 h as compared to the non-exercised hand. The EMG RMS amplitude was also reduced immediately after the exercise, but was increased at 24 and 48 h. Isometric force was reduced immediately after the exercise as compared to days 1, 6, and the 24 and 48 h post-exercise assessments with a greater reduction following the tolperisone hydrochloride treatment and the reduction was more in tolperisone group as compared to the placebo group. The results suggest, that the prophylactic intake of tolperisone hydrochloride provides no relief to pain in course of post-exercise muscle soreness but results in reduction in isometric force.

Effect of muscle relaxants on experimental jaw-muscle pain and jaw-stretch reflexes: a double-blind and placebo-controlled trial

A randomised, double-blind, placebo-controlled three-way cross-over study was performed to investigate the effect of two muscle relaxants (tolperisone hydrochloride and pridinol mesilate) on experimental jaw-muscle pain and jaw-stretch reflexes. Fifteen healthy men participated in three randomised sessions separated by at least 1 week. In each session 300 mg tolperisone, 8 mg pridinol mesilate or placebo was administered orally as a single dose. One hour after drug administration 0.3 ml hypertonic saline (5.8%) was injected into the right masseter to produce muscle pain. Subjects continuously rated their perceived pain intensity on an electronic 10-cm visual analogue scale (VAS). The pressure pain threshold (PPT) was measured and short-latency reflex responses were evoked in the pre-contracted (15% maximal voluntary contraction) masseter and temporalis muscles by a standardised stretch device (1 mm displacement, 10 ms ramp time) before (baseline), 1 h after medication (post-drug), during ongoing experimental muscle pain (pain-post-drug), and 15 min after pain had vanished (post-pain). Analysis of variance demonstrated significantly lower VAS peak pain scores (5.9 +/- 0.4 cm) after administration of tolperisone hydrochloride compared with pridinol mesilate (6.8 +/- 0.4 cm) and placebo (6.6 +/- 0.4 cm) (P=0.020). Administration of pridinol mesilate was associated with a significant decrease in PPTs compared with tolperisone hydrochloride and placebo (P=0.002) after medication, but not after experimental jaw-muscle pain. The normalised peak-to-peak amplitude of the stretch reflexes were not significantly influenced by the test medication (P=0.762), but were in all sessions significantly facilitated during ongoing experimental jaw-muscle pain (P=0.034). In conclusion, tolperisone hydrochloride provides a small, albeit significant reduction in the perceived intensity of experimental jaw-muscle pain whereas the present dose had no effect on the short-latency jaw-stretch reflex.