Efficacy and Safety of Bupivacaine, Triamcinolone, and Sodium Chloride in Treating Trapezius Myofascial Syndrome in Fibromyalgia Patients

The primary objective of this study is to compare the **efficacy** in improving both local and generalized pain in patients with fibromyalgia who present with myofascial trapezius pain syndrome. This will be assessed by evaluating the duration of pain relief following regional administration of bupivacaine/triamcinolone versus physiological saline versus placebo in the interfascial space between the trapezius and supraspinatus muscles and between the trapezius and levator scapulae muscles. This is clinically relevant as it aims to identify the most effective treatment for pain management in this patient population, potentially improving their quality of life.

Secondary objectives include: - Analyzing differences in general pain, sleep quality, mood, quality of life, and functional capacity before and after administration of the active drug (bupivacaine and triamcinolone). - Comparing the significant difference in the effect of the active drug (chemical and mechanical action) versus physiological saline (only mechanical action) in reducing symptoms in these patients.

The clinical trial involves participants diagnosed with **fibromyalgia** who also experience trapezius myofascial syndrome. The study population includes both male and female subjects over the age of 18. Participants are required to have a stable health status, specifically those who have not initiated a new treatment or have maintained a consistent treatment regimen over the past three months. The trial population was selected based on the presence of spontaneous, continuous pain in the upper trapezius lasting more than three months, with a pain intensity scale greater than 3 according to the Visual Analogue Scale (VAS). Participants may have been using weak opiates, paracetamol, or metamizol as rescue medication. The sponsor has not provided the total number of participants involved in the study. The trial includes a vulnerable population, and all participants have provided informed consent. Lifestyle factors such as diet and physical activity were not specified in the available data.

The clinical trial is designed to evaluate the **efficacy** and safety of local treatment for trapezius myofascial syndrome in patients with fibromyalgia. This study employs a randomized, double-blind, controlled design to compare the effects of bupivacaine/triamcinolone, physiological saline, and placebo. The trial is expected to last until June 2025, with participant recruitment having commenced in June 2023. Participants will be involved in the study for a maximum treatment period of one day, with follow-up assessments conducted at weeks 2, 4, and 12.

Study visits are structured to ensure comprehensive data collection and participant safety. The inclusion visit, or screening, will confirm eligibility based on criteria such as age, fibromyalgia diagnosis, and pain characteristics. Following randomization, participants will receive intramuscular injections in the interfascial space between the trapezius and supraspinatus muscles and between the trapezius and levator scapulae muscles. Follow-up visits will assess primary and secondary endpoints, including the Visual Analogue Scale (VAS) for regional and general pain, fatigue, sensitivity points, and quality of life measures. The end-of-study visit will conclude the participant's involvement, ensuring all data is collected and any adverse events are addressed.

Participants are expected to remain in the study for the entire duration unless specific conditions necessitate early termination. These conditions include the occurrence of significant adverse events, withdrawal of consent, or non-compliance with study procedures. The trial aims to provide valuable insights into the management of trapezius myofascial syndrome in fibromyalgia patients, contributing to improved therapeutic strategies.

The clinical trial involves the administration of **KENACORT 40 mg/ml**, a **suspension for injection** containing the active substance **triamcinolone acetonide**. This medication is utilized for its anti-inflammatory properties. The pharmaceutical form is a suspension for injection, and it is administered via **intramuscular use**. The maximum daily and total dose is 1 ml, with a treatment period limited to one day. The product is manufactured by Bristol-Myers Squibb S.R.L. and is not a pediatric formulation.

Another component of the trial is the use of **Suero Fisiológico Braun 0.9%**, a **solution for injection** containing **sodium chloride**. This product serves as a solvent for parenteral use and is also administered intramuscularly. The maximum daily and total dose is 10 ml, with a treatment period of one day. It is produced by B.BRAUN MEDICAL, S.A. and is not intended for pediatric use.

**Lidocaína B. Braun 20 mg/ml**, a **solution for injection** containing **lidocaine hydrochloride**, is included in the trial for its anesthetic properties. This solution is administered intramuscularly, with a maximum daily and total dose of 1 ml, and a treatment period of one day. The manufacturer is B.BRAUN MEDICAL, S.A., and the formulation is not pediatric.

Lastly, the trial includes **BUPIVACAÍNA PHYSAN 0.25%**, a **solution for injection** containing **bupivacaine hydrochloride**. This anesthetic is administered intramuscularly, with a maximum daily and total dose of 4.5 ml, and a treatment period of one day. The product is manufactured by LAPHYSAN, S.A.U. and is not a pediatric formulation.

The efficacy of the clinical trial will be assessed through a series of primary and secondary endpoints. The primary endpoint is the evaluation of regional trapezius pain using the Visual Analogue Scale (VAS) at weeks 2, 4, and 12. This scale will provide a quantitative measure of pain intensity, allowing for a comparison of the efficacy of different treatments administered in the interfascial space between the trapezius and supraspinatus muscles and between the trapezius and levator scapulae muscles.

Secondary endpoints include a broader assessment of the patient's condition, such as the VAS for general pain and fatigue, sensitivity points measured by an algometer with a force of 4 kg, and the use of the Widespread Pain Index (WPI) and Symptom Severity Scale (SSS). Additional assessments will be conducted using the Pittsburgh Sleep Quality Index (PSQI) for sleep evaluation, the Fibromyalgia Impact Questionnaire (FIQ) for functional capacity, and the SF-36 for quality of life. The level of anxiety and depression will be measured using the Hospital Anxiety and Depression Scale (HAD).

These assessments will be conducted at specified time points throughout the trial to ensure a comprehensive evaluation of the treatment's impact on patients with **fibromyalgia** and myofascial trapezius pain syndrome. The use of validated scales and instruments ensures the reliability and accuracy of the efficacy data collected during the trial.