Muscle Strength Decline Caused by Eperisone Hydrochloride: A Case Report.

A 65-year-old female with thoracic spinal stenosis and incomplete paraplegia underwent T11-T12 posterior thoracic interbody fusion. During postoperative rehabilitation, she experienced thigh pain, involuntary lower limb convulsions, and muscle fatigue. Despite being prescribed eperisone hydrochloride for relief, her muscle strength decreased after 14 doses. This adverse effect, not listed in the latest Chinese medication instructions, subsided 4 days after discontinuation. This case suggests eperisone hydrochloride potentially caused reversible muscle strength decline, highlighting its potential unsuitability for incomplete paraplegia patients due to possible further muscle strength reduction. We propose updating the medication instructions to alert clinicians to this risk.

Bilateral tonic seizures probably induced by eperisone hydrochloride: a case report.

Eperisone hydrochloride is a central muscle relaxant used to treat osteoporosis. Seizures are rare side effects of eperisone hydrochloride and have been previously reported in the medical literature in overdose situations but not at regular doses. This case report describes a 42-year-old male painter who developed severe bilateral tonic seizures after the initiation of eperisone hydrochloride at regular doses for low back pain. Symptoms gradually eased in the days following the discontinuation of eperisone hydrochloride and antiepileptic treatment, with no recurrence. This rare adverse drug reaction warrants clinical awareness; however, the mechanisms underlying these adverse reactions remain to be clarified.

Effects of Eperisone Hydrochloride and Non-Steroid Anti-Inflammatory Drugs (NSAIDs) for Acute Non-Specific Back Pain with Muscle Spasm: A Prospective, Open-Label Study.

BACKGROUND: Low back pain (LBP) occurs as a common condition and may harm the patient's quality-of-life. Non-steroid anti-inflammatory drugs (NSAIDs) and eperisone form a drug regiment that has been reported as effective in improving low back pain, yet the evidence for its efficacy and safety is lacking. OBJECTIVE: The aim of this study was to evaluate the effect of eperisone hydrochloride and ibuprofen compared with ibuprofen alone in reducing symptoms of patients with acute non-specific back pain with a muscle spasm. METHODS: This was an open-label, prospective study involving 100 subjects with symptoms of back pain and muscle spasm. Eligible participants were randomly allocated to an experimental group (54 patients) and a control group (46 patients). The experimental group received eperisone 50 mg three times daily + ibuprofen 400 mg twice daily, and the control group received ibuprofen 400 mg twice daily over a 4-week duration. The primary outcomes were measured with the visual analog scale (VAS), and finger-to-floor (FTF) distance at baseline, week 2, and week 4. RESULTS: After 4 weeks of follow-up, results from 59 subjects were collected. In both groups, VAS and FTF were decreased compared to baseline. Clinically significant pain reduction (>50% than baseline) was observed to be higher in the experimental group compared with the control group in the fourth week (72.4% vs 46.7%, P<0.05). At the end of the study, pain reduction in the experimental group was more significant compared to the control group (28.13±24.72 vs 34.42±28.47) and participants mobility (FTF distance <10 cm) improved in both groups, especially in the experimental group (75.9% vs 70%). There was no difference in adverse events between groups (P>0.05). CONCLUSION: The combination of eperisone hydrochloride and ibuprofen effectively reduces pain and improves functional outcomes over ibuprofen alone with a similar safety profile in these patients with acute non-specific back pain with muscle spasm.

Biophysical Study on the Interaction between Eperisone Hydrochloride and Human Serum Albumin Using Spectroscopic, Calorimetric, and Molecular Docking Analyses.

Eperisone hydrochloride (EH) is widely used as a muscle relaxant for patients with muscular contracture, low back pain, or spasticity. Human serum albumin (HSA) is a highly soluble negatively charged, endogenous and abundant plasma protein ascribed with the ligand binding and transport properties. The current study was undertaken to explore the interaction between EH and the serum transport protein, HSA. Study of the interaction between HSA and EH was carried by UV-vis, fluorescence quenching, circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, Förster's resonance energy transfer, isothermal titration calorimetry and differential scanning calorimetry. Tryptophan fluorescence intensity of HSA was strongly quenched by EH. The binding constants (Kb) were obtained by fluorescence quenching, and results show that the HSA-EH interaction revealed a static mode of quenching with binding constant Kb ≈ 104 reflecting high affinity of EH for HSA. The negative ΔG° value for binding indicated that HSA-EH interaction was a spontaneous process. Thermodynamic analysis shows HSA-EH complex formation occurs primarily due to hydrophobic interactions, and hydrogen bonds were facilitated at the binding of EH. EH binding induces α-helix of HSA as obtained by far-UV CD and FTIR spectroscopy. In addition, the distance between EH (acceptor) and Trp residue of HSA (donor) was calculated 2.18 nm using Förster's resonance energy transfer theory. Furthermore, molecular docking results revealed EH binds with HSA, and binding site was positioned in Sudlow Site I of HSA (subdomain IIA). This work provides a useful experimental strategy for studying the interaction of myorelaxant with HSA, helping to understand the activity and mechanism of drug binding.

Eperisone hydrochloride-induced maculopapular rash.

Here, we report a case of a 30-year-old male who was prescribed eperisone hydrochloride for body pain and loose stools after which he developed severe maculopapular rash. Eperisone hydrochloride is an analgesic and antispastic drug used for spastic diseases such as spastic paralysis in cerebrovascular diseases, cervical spondylosis, and periarthritis. The drug is marketed in most of the Asian countries including India, but it is not licensed. Studies show the history of hypersensitivity in other countries, but this is the first reported case in India.

Simultaneous determination of eperisone hydrochloride and paracetamol in mouse plasma by high performance liquid chromatography-photodiode array detector.

This paper reports the validation of a quantitative high performance liquid chromatography-photodiode array (HPLC-PDA) method for the simultaneous analysis, in mouse plasma, of eperisone hydrochloride and paracetamol by protein precipitation using zinc sulphate-methanol-acetonitrile. The analytes were resolved on a Gemini C18 column (4.6 mm × 250 mm; 5 µm particle size) using a gradient elution mode with a run time of 15 min, comprising re-equilibration, at 60°C (± 1°C). The method was validated over the concentration range from 0.5 to 25 µg/mL for eperisone hydrochloride and paracetamol, in mouse plasma. Ciprofloxacin was used as Internal Standard. Results from assay validations show that the method is selective, sensitive and robust. The limit of quantification of the method was 0.5 µg/mL for eperisone hydrochloride and paracetamol, and matrix-matched standard curves showed a good linearity, up to 25 µg/mL with correlation coefficients (r(2))≥ 0.9891. In the entire analytical range the intra and inter-day precision (RSD%) values were ≤ 1.15% and ≤ 1.46% for eperisone hydrochloride, and ≤ 0.35% and ≤ 1.65% for paracetamol. For both analytes the intra and inter-day trueness (bias%) values ranged, respectively, from -5.33% to 4.00% and from -11.4% to -4.00%. The method was successfully tested in pharmacokinetic studies after oral administration in mouse. Furthermore, the application of this method results in a significant reduction in terms of animal number, dosage, and improvement in speed, rate of analysis, and quality of pharmacokinetic parameters related to serial blood sampling.

Development and Validation of UV-Visible Spectrophotometric Method for Simultaneous Determination of Eperisone and Paracetamol in Solid Dosage Form.

PURPOSE: Eperisone Hydrochloride (EPE) is a potent new generation antispasmodic drug which is used in the treatment of moderate to severe pain in combination with Paracetamol (PAR). Both drugs are available in tablet dosage form in combination with a dose of 50 mg for EPE and 325 mg PAR respectively. METHODS: The method is based upon Q-absorption ratio method for the simultaneous determination of the EPE and PAR. Absorption ratio method is used for the ratio of the absorption at two selected wavelength one of which is the iso-absorptive point and other being the λmax of one of the two components. EPE and PAR shows their iso-absorptive point at 260 nm in methanol, the second wavelength used is 249 nm which is the λmax of PAR in methanol. RESULTS: The linearity was obtained in the concentration range of 5-25 µg/mL for EPE and 2-10 µg/mL for PAR. The proposed method was effectively applied to tablet dosage form for estimation of both drugs. The accuracy and reproducibility results are close to 100% with 2% RSD. RESULTS of the analysis were validated statistically and found to be satisfactory. The results of proposed method have been validated as per ICH guidelines. CONCLUSION: A simple, precise and economical spectrophotometric method has been developed for the estimation of EPE and PAR in pharmaceutical formulation.

Pharmacokinetic interactions between eperisone hydrochloride and aceclofenac: a randomized, open-label, crossover study of healthy Korean men.

BACKGROUND: Eperisone hydrochloride, a centrally acting muscle relaxant, is a calcium antagonist that causes vasodilation and antispastic actions. Aceclofenac, an anti-inflammatory analgesic and antipyretic drug, has similar efficacy and improved gastrointestinal tolerance compared with other nonsteroidal anti-inflammatory drugs, such as diclofenac. Although eperisone hydrochloride and aceclofenac are frequently coadministered, no published studies have reported on the pharmacokinetic interactions between these 2 drugs. OBJECTIVE: The aim of this study was to investigate any pharmacokinetic interactions between eperisone hydrochloride and aceclofenac in healthy Korean men. METHODS: This was a randomized, open-label, crossover study. Each participant was randomly assigned to 1 of 6 treatment sequences and received eperisone hydrochloride (3 doses of 50 mg each), aceclofenac (2 doses of 100 mg each), or both as a single dose with a 7-day washout period between each dose. Blood samples were collected ≤ 24 hours after dosing, and plasma eperisone hydrochloride and aceclofenac concentrations were determined using validated LC/MS-MS. Pharmacokinetic analyses were conducted using noncompartmental methods. A safety profile was determined using the measurement of vital signs, ECG, and clinical laboratory tests. RESULTS: A total 24 of men were enrolled, and all completed the study. The geometric mean ratios (90% CIs) of the Cmax and AUC0-∞ values for eperisone were 1.18 (0.828-1.673) and 1.12 (0.836-1.507), respectively. The geometric mean ratios (90% CIs) of the Cmax and AUC0-∞ for aceclofenac were 0.93 (0.847-1.022) and 1.01 (0.979-1.036), respectively. A total of 7 adverse events were reported in 7 men. All adverse events were mild, and no significant differences were found between treatment groups. CONCLUSION: No clinically significant pharmacokinetic differences exist between 150 mg eperisone hydrochloride and 200 mg aceclofenac when administrated as a monotherapy or in combination.

Relative bioavalability of hydrochloride eperisone granule in healthy volunteers / 中国临床药理学与治疗学

Aim The relative bioavalability of hydrochloride eperisone granule in 10 healthy volunteers was studied. Methods The time-plasma concentrations of hydrochloride eperisone granule, as test drug, and myonal, as reference drug, were determined by GC-MS, with tolperisone senuing as internal standard.The pharmacokinetic parameters of both reference and test drug were calculated and analyzed with two-one side test and confidential interval test. Results The results showed that the AUC0-8, AUC0-∞, Cmax, Tpeak, t1/2(?) and t1/2(?) were (17.9?1.3)ng?h?ml-1 and(18.6?1.6)ng?h?ml-1, (19.1?1.2)ng?h?ml-1 and (20.2?1.6)ng?h?ml-1, (5.2?0.5)ng?ml-1 and (5.4?0.5) ng?ml-1, (1.05?0.18)h and (1.08?0.23)h, (0.78? 0.13)h and ( 0.82?0.14)h,( 1.8?0.3)h and (1.8?0.3)h, respectively. The relative bioavalability of test drug was (105? 5)%. Conclusion It can be concluded that the test and reference are bioequivalented between individuals, preparations and periods.

The Clinical Evaluation Of Eperisone Hydrochloride (Mulex) / 대한류마티스학회지

Conservative treatment is the main therapy for cervicobrachial syndrome, scapulohumeral periarthritis, and lumbago as diseases with both pain and myotonia. The-conservative treatment mainly consists of medication, physiotherapy, and kinesiotherapy. In the recent years, attempts have been made to give relief to myotonia through combination therapy with antiinflammatory analgesics and muscle relaxants. The muscle relaxants using in general are tolperisone hydrochloride, chlormezanone, and diazepam. Eperizone hydrochloride(Mulex tablet) is a beta-propriophenone derivatives and a central acting muscle relaxant, And it benefited subjective symptoms such as muscular pain (lumbago, neck pain) and a stiff muscle sensation (shoulder tension, tension feeling of lower limb). Among 22 patients, there were 14 lumbagos, two cephalobrachial syndromes, one scapulohumeral periarthritis, and five combined patients were chosen and duration of symptom was 5 years (3months-15years) in average. Mulex tablet was administered in a dose of 3 tablets (150rag) per day in 22 patients for 6 weeks prospectively. We analysed general improvement rating (GIR), general usefulness rating(GUR), and overall safety rating. The general improvement rate was 78% and the aggravation rate was 4%. The complication after, madication was infrequently gastrointestinal trouble. Incidence of side effect was 22%, but all these complications were insignificant. Hematology, blood chemistry, and urinalysis after medication were normal.