An interventional study of Lidocaine 2 % and Lidocaine + Sodium Bicarbonate in Myofacial Pain, Myofacial Pain Syndrome and Myofacial Pain Syndromes, sponsored by Cairo University. Recruiting at 1 site in Egypt. Open to participants aged 16 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by Cairo University · Not applicable, Interventional, and Treatment
This study is designed to evaluate a method to improve the treatment of myofascial pain syndrome (MPS), a common condition that causes muscle pain, tenderness, and reduced movement due to the presence of trigger points in muscles.
A commonly used treatment for this condition is the injection of a local anesthetic called lidocaine into these trigger points to relieve pain. However, the pain relief from lidocaine alone may be temporary.
In this study, we are investigating whether adding a small amount of sodium bicarbonate to lidocaine can improve its effectiveness. Sodium bicarbonate may reduce the pain during injection and help the anesthetic work faster and possibly last longer.
Participants in this study will be randomly assigned into one of two groups:
One group will receive lidocaine alone. The other group will receive lidocaine mixed with sodium bicarbonate.
The injection will be performed once into the painful muscle trigger points under sterile conditions.
Pain levels will be assessed using a simple pain scale, and muscle activity will be measured using a non-invasive technique called surface electromyography (sEMG), which records muscle electrical activity. These measurements will be taken before the injection, immediately after, and during follow-up visits.
Participants may experience mild discomfort during or after the injection, but all procedures are routinely used in clinical practice. Safety measures will be in place to manage any possible side effects.
The goal of this study is to determine whether the combined injection provides better pain relief, improves muscle function, and enhances patient comfort compared to lidocaine alone.
Study Overview
This study is a randomized, parallel-group, single-blind clinical trial designed to evaluate the clinical effectiveness of adding sodium bicarbonate to lidocaine in the treatment of myofascial pain syndrome (MPS). The study compares outcomes between lidocaine alone and buffered lidocaine using surface electromyography (sEMG) and pain assessment tools.
Background
Myofascial pain syndrome is a prevalent musculoskeletal disorder characterized by the presence of myofascial trigger points, leading to localized or referred pain, functional limitation, and reduced quality of life. Although trigger point injections with lidocaine are widely used and provide rapid pain relief, their effects are often temporary and may require repeated administration.
Buffered lidocaine, achieved by adding sodium bicarbonate, has been proposed to enhance anesthetic performance by increasing the pH of the solution. This increases the proportion of the non-ionized form of lidocaine, facilitating faster onset of action, improved tissue penetration, and reduced pain during injection. However, its role in managing MPS has not been sufficiently established.
Rationale
There is currently no consensus regarding the optimal injectable solution for trigger point therapy. This study aims to determine whether buffering lidocaine with sodium bicarbonate improves clinical outcomes in terms of pain reduction, patient comfort, and muscle function compared to lidocaine alone.
Objectives
The primary objective is to evaluate the effect of adding sodium bicarbonate to lidocaine on pain reduction in patients with myofascial pain syndrome.
Secondary objectives include:
Assessing pain experienced during injection Evaluating changes in muscle activation patterns and functional recovery Study Design Type: Randomized controlled clinical trial Design: Parallel, two-arm Allocation ratio: 1:1 Blinding: Single-blind (participants blinded) Framework: Superiority Participants
Participants will be recruited from outpatient clinics of the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Cairo University.
Eligible participants include patients diagnosed with myofascial pain syndrome presenting with active trigger points and moderate to severe pain.
Interventions
Participants will be randomly assigned into two groups:
Control Group: Injection with 2% lidocaine alone Intervention Group: Injection with 2% lidocaine buffered with sodium bicarbonate (8.4%)
The buffered solution will be freshly prepared immediately prior to injection under aseptic conditions.
All injections will be administered into identified trigger points using a standardized technique.
Outcome Measures Primary Outcome
Pain reduction assessed using:
Visual Analog Scale (VAS) Surface electromyography (sEMG) Secondary Outcome Pain during injection (VAS) Tertiary Outcome Changes in muscle activation during voluntary contraction (sEMG)
Assessments will be conducted at baseline, immediately after injection, and at follow-up visits.
Safety Considerations
All procedures will follow strict aseptic protocols. Patients will be monitored immediately after injection for any adverse reactions.
Possible risks include:
Pain at injection site Vasovagal reactions Local tissue injury Rare allergic reactions
Risk mitigation measures include proper injection technique, dose calculation, aspiration before injection, and availability of emergency equipment.
Data Collection and Analysis
Data will be collected using standardized forms and stored securely. Statistical analysis will be performed to compare outcomes between both groups, with significance set at p ≤ 0.05.
Ethical Considerations
The study will be conducted following ethical guidelines and will require approval from the institutional ethics committee. Written informed consent will be obtained from all participants prior to enrollment. Participant confidentiality will be strictly maintained.
Expected Impact
This study aims to provide evidence on whether buffering lidocaine with sodium bicarbonate improves treatment outcomes in myofascial pain syndrome. The findings may help guide clinical practice toward more effective and comfortable treatment options.
182 studies on the registry are indexed under Facial Pain; 61 are open to participants now.
This study's planned enrollment of 30 is below the median of 50 across 132 interventional studies indexed under Facial Pain.
Browse Facial Pain studies →Cairo University is the lead sponsor of 4,941 studies on the registry; 1,458 are open to participants now.
Of its 37 completed or terminated interventional studies of FDA-regulated products, 5 (14%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patients aged 16 to 70 years Clinical diagnosis of myofascial pain syndrome (MPS) Presence of active myofascial trigger points Pain duration ≥ 3 months Pain intensity ≥ 4 on the Visual Analog Scale (VAS) Trigger points located in accessible muscles No trigger point injection in the affected area within the past 3 months Ability and willingness to provide Willingness to comply with study procedures and follow-up visits
Exclusion Criteria:
Known allergy or to lidocaine, sodium bicarbonate, or other amide-type local anesthetics Current use of anticoagulants or presence of bleeding disorders Local or systemic infection at or near the injection site History of fibromyalgia, cancer-related pain, or central pain syndromes Major psychiatric disorders (e.g., schizophrenia, severe depression) Recent trauma or surgery to the neck, shoulder, or back within the past 6 months Use of analgesics (e.g., NSAIDs, opioids) within 5 days prior to injection Severe systemic diseases (e.g., uncontrolled diabetes, liver failure, kidney failure, severe cardiovascular disease)
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Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants in this group will receive a single-session trigger point injection using 2% lidocaine without any additives. The injection will be administered into the identified myofascial trigger points using a standardized technique under aseptic conditions.
Drug: Lidocaine 2 %
Participants in this group will receive a single-session trigger point injection using 2% lidocaine combined with sodium bicarbonate. The buffered solution is intended to reduce injection pain and enhance anesthetic effectiveness.
Drug: Lidocaine + Sodium Bicarbonate
2% lidocaine (preservative-free, without vasoconstrictor) will be administered via intramuscular injection into the identified trigger points. Approximately 1.8 mL will be injected per point using a sterile 25-27 gauge needle. The injection will be performed using a standardized "fast-in, fast-out" (peppering) technique.
Drug pages: Lidocaine · Sodium Bicarbonate
A buffered anesthetic solution will be prepared immediately before injection by mixing 2% lidocaine with 8.4% sodium bicarbonate in a ratio of 9:1 (1.8 mL lidocaine + 0.2 mL sodium bicarbonate per injection point). The solution will be administered via intramuscular injection into trigger points using a sterile 25-27 gauge needle and standardized injection technique.
Reduction in Pain Intensity
Pain intensity will be assessed using the Visual Analog Scale (VAS) (0-10). In addition, surface electromyography (sEMG) will be used to objectively evaluate muscle activity at rest (MVC%). A reduction in VAS scores and sEMG activity indicates improvement.
Time frame: Baseline, immediately after injection, and 2 weeks post-injection
Pain During Injection
Pain experienced during the injection procedure will be measured using the Visual Analog Scale (VAS) (0-10), immediately after completion of the injection.
Time frame: Immediately after injection
Change in Muscle Activation Pattern
Changes in muscle activation during voluntary contraction will be assessed using surface electromyography (sEMG) (MVC%). Improvement indicates better functional muscle recovery.
Time frame: Baseline and 2 weeks post-injection
Plan to share: No
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Studies of the drugs tested here: Lidocaine · Sodium Bicarbonate