- Also known as Xylocaine and sometimes Lignocaine
- Local Anesthetic
- Antiarrhythmic drug – for ventricular arrhythmias (but Amiodarone is mostly used for this)
- The first Amino-Amide local anesthetic
- First marketed in 1949
- Alters signal conduction in neurons by blocking the fast voltage gated sodium channels in the neuronal cell membrane. Thus prevents depolarization of the postsynaptic neuron.
Esters and Amide local anesthetics – way to remember which
- Esters have only one “i” in the name: Procaine, Cocaine
- Amides have over two “i”s in the name: Lidocaine, Bupivicaine, Prilocaine.
Contraindications to using Lidocaine
- Porphyria – rare inherited or aquired disorders of enzymes which produce porphyrins and heme resulting in neurological complications (abdominal pain, vomiting, neuropathy) or skin problems.
- Heme is one the best known porphyrin the pigment in red blood cells and cofactor of the protein hemoglobin.
- Porphyrin means purple
- can occur with topical creams
- Treatment with IV lipid emulsions can reverse the effects of lidocaine toxicity.
- Allergic reactions rare.
- CNS (central nervous system) and cardiovascular effects
- CNS at lower doses, cardiac at higher doses
- CNS: nervousness, tingling around mouth, tinnitus, tremor, dizziness, blurred vision, seizures, depression, loss of consciousness
- Cardiovascular effects: hypotension, bradycardia, arrhythmias
Insensitivity to Lidocaine
- Exists in some patients with ADHD and Ehlers-Danlos syndrome
Lidocaine Safety and Toxic doses
- Particular care in calculating maximum safe dose for young children
- Peak blood levels of lidocaine usually occur 10-25 minutes after injection – the point at which toxic effects are likely to be seen.
- Maximum safe dose of lidocaine without vasoconstrictor (ie. epinephrine) is 3-4.5 mg/kg (duration of action 1 hour). No more than 300 mg (30 cc’s of 1% Lidocaine) at once.
- Maximum safe dose of lidocaine with vasoconstrictor is 5-7 mg/kg (duration of action 2-6 hours)
How to calculate Maximum safe doseage of Lidocaine
- You need to know that 1% Lidocaine solution is 10 mg/mL
- Example Calculation for a 70 Kg man: Lido 1% with Epi: keep under 7 mg/Kg. 7×70 = 490 mg for 70 kg man. Divide 490 mg by 10 mg/ML = 49 ml.
How is this important to our Plastic Surgical and Acupuncture practice?
- We use lidocaine in plastic surgical procedures – topical and subcutaneous – for removal of moles, injection of fillers such as Juvederm, and sometimes for Botox.
- I also use injected lidocaine as part of some trigger point deactivation practices in acupuncture.
Cosmetic Procedures at Surgical Artistry which may use Lidocaine
- Liposuction – tumescent lidocaine
- Mole removal – injected subcutaneous local lidocaine
- Fillers – Juvederm – some formulations have lidocaine within the product
- Fillers and Botox – sometimes we use topical lidocaine
- Face Veins – sometimes we use topical lidocaine
- Minor office surgeries – we use injected lidocaine in the subcutaneous level