From the Guidelines
Lidocaine is generally preferred over bupivacaine for trigger point injections due to its rapid onset of action and lower cardiotoxicity risk. Lidocaine (1% or 2% concentration) provides rapid onset of action (within minutes) and typically lasts 1-2 hours, making it suitable for immediate pain relief 1. Bupivacaine (0.25% or 0.5% concentration) has a slower onset but longer duration of action (4-8 hours), which may be beneficial for patients needing extended relief. For standard trigger point injections, 1-2 mL of anesthetic per injection site is typically sufficient.
Key Considerations
- Lidocaine has a lower maximum recommended dose with epinephrine (7.0 mg/kg) compared to bupivacaine (3.0 mg/kg) 1
- Bupivacaine might be preferred in cases where prolonged analgesia is desired or when patients have shown inadequate response to lidocaine
- Both medications work by blocking sodium channels in nerve membranes, preventing action potential generation and transmission of pain signals
- Some clinicians combine the two agents to achieve both rapid onset (lidocaine) and prolonged effect (bupivacaine), though this practice varies by provider preference and patient needs
Safety Profile
- Lidocaine is favored for its safety profile with lower cardiotoxicity risk compared to bupivacaine, especially important when multiple injections are needed 1
- The maximum allowable safe dosage of local anesthetics should be calculated before administration to avoid excessive doses 1
- Lower doses should be used in very vascular areas, and the patient's age and medical history should be considered when selecting a local anesthetic agent 1
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Comparison of Lidocaine and Bupivacaine for Trigger Point Injection
- Lidocaine and bupivacaine are both local anesthetics used for trigger point injections to manage myofascial pain syndrome [(2,3,4)].
- A study comparing lidocaine patch, placebo patch, and anesthetic injection (bupivacaine) found that both lidocaine patch and bupivacaine injection decreased subjective symptoms and increased pain thresholds 2.
- Another study found that trigger point injections with 0.5% lidocaine were effective in reducing pain and tenderness, and had less postinjection soreness compared to dry needling 3.
- A comparison of bupivacaine, etidocaine, and saline for trigger-point therapy found that bupivacaine and etidocaine were generally preferred over saline in several pain-tested categories 4.
Efficacy and Safety
- Lidocaine injections have been shown to be effective in reducing pain intensity and improving range of motion [(3,5,6)].
- Bupivacaine injections have also been shown to be effective in reducing pain and tenderness [(2,4)].
- However, bupivacaine injections may cause more discomfort and local tissue hypersensitivity compared to lidocaine injections 2.
Clinical Implications
- The choice between lidocaine and bupivacaine for trigger point injection may depend on the individual patient's response and the specific clinical scenario [(3,5,4)].
- Lidocaine may be a better option for patients who are sensitive to pain or have a history of postinjection soreness 3.
- Bupivacaine may be a better option for patients who require a longer duration of action or have more severe pain [(2,4)].