From the FDA Drug Label
DOSAGE & ADMINISTRATION Table 1 (Recommended Dosages) summarizes the recommended volumes and concentrations of Lidocaine HCl Injection for various types of anesthetic procedures. LIDOCAINE HCI INJECTION, USP 2% 1000 mg/50 mL (20 mg/mL) 50 mL VIAL
2 percent lidocaine can be used for IM. The dosage and concentration of lidocaine to be used depend on several factors, including the type and extent of the surgical procedure, depth of anesthesia, and physical condition of the patient.
- The lowest concentration and smallest dose that will produce the desired result should be given.
- Dosages should be reduced for children and for the elderly and debilitated patients and patients with cardiac and/or liver disease 1. The available concentration of 2% lidocaine is listed in the supplied dosage forms 2.
From the Research
No, 2% lidocaine should not be used for intramuscular (IM) injections. Lidocaine is a local anesthetic intended for local infiltration, nerve blocks, or topical application, not as a vehicle for IM medication administration. For IM injections, you should use appropriate diluents like sterile water, normal saline, or specifically formulated vehicles designed for intramuscular use. Using lidocaine as an IM vehicle could potentially cause tissue irritation, alter the absorption rate of the medication being administered, and may interfere with the therapeutic effects of the injected medication. Additionally, lidocaine itself has systemic effects including potential cardiac conduction changes if absorbed systemically in sufficient quantities 3. If you're concerned about injection pain, proper injection technique, appropriate needle selection, and injection site preparation are better approaches to minimize discomfort during IM administration.
Some key points to consider:
- Lidocaine has anti-inflammatory properties and can inhibit TNF-α secretion in lipopolysaccharide-stimulated leucocytes in human blood samples 4.
- The order of neurotoxicity of local anesthetics is procaine = mepivacaine < ropivacaine = bupivacaine < lidocaine < tetracaine < dibucaine 5.
- Lidocaine spray can be used as a first line of local anesthetic during the closure of I-II-grade perineal lacerations, with comparable efficacy to mepivacaine infiltration 6. However, these points do not support the use of 2% lidocaine for IM injections, and the potential risks and complications associated with its use in this context should be prioritized.
In terms of morbidity, mortality, and quality of life, the use of 2% lidocaine for IM injections is not recommended due to the potential risks and complications associated with its use. Instead, alternative methods for minimizing injection pain and discomfort should be prioritized, such as proper injection technique, appropriate needle selection, and injection site preparation.