Lidocaine
[CAS# 137-58-6]

Identification

• Classification: API >> Anesthetic agents >> Local anesthetics
• Name: Lidocaine
• Synonyms: 2-(Diethylamino)-N-(2,6-dimethylphenyl)-acetamide; Xylocaine
• Molecular Formula: C₁₄H₂₂N₂O
• Molecular Weight: 234.34
• Protein Sequence: G
• CAS Registry Number: 137-58-6
• EC Number: 205-302-8
• SMILES: CCN(CC)CC(=O)NC1=C(C=CC=C1C)C

Properties

• Solubility: 47 mg/mL (DMSO), 9 mg/mL (water)
• Density: 1.0±0.1 g/cm³, Calc.^*
• Melting point: 66-69 °C
• Index of Refraction: 1.512, Calc.^*
• Boiling Point: 372.7±52.0 °C (760 mmHg), Calc.^*, 182 °C (4 mmHg)
• Flash Point: 179.2±30.7 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302
• Safety Statements: P264-P270-P301+P317-P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Reproductive toxicity	Repr.	2	H361
Skin sensitization	Skin Sens.	1	H317
Respiratory sensitization	Resp. Sens.	1	H334
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	3	H331
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	3	H311
Acute toxicity	Acute Tox.	3	H301

Discovery and Applications

Lidocaine, chemically known as 2-(diethylamino)-N-(2,6-dimethylphenyl)acetamide, is a local anesthetic and antiarrhythmic agent widely used in medical practice. Its discovery dates back to the late 1940s when it was first synthesized by Swedish chemist Nils Löfgren. Lidocaine was developed as a safer and more effective alternative to procaine, the then-popular local anesthetic. The introduction of lidocaine marked a significant advancement in the field of anesthesia due to its rapid onset of action and relatively short duration compared to earlier anesthetics.

Lidocaine acts by blocking voltage-gated sodium channels, preventing the initiation and conduction of nerve impulses. This mechanism of action is fundamental to its effectiveness as a local anesthetic. When administered locally, lidocaine provides anesthesia to a specific area, allowing for various medical and dental procedures to be performed without pain. The compound is available in several formulations, including injectable solutions, topical creams, and gels, making it versatile for various clinical applications.

The applications of lidocaine extend beyond local anesthesia. It is commonly used in dental procedures, minor surgical interventions, and various dermatological treatments. Its efficacy in alleviating pain during these procedures has made it a staple in healthcare settings. Furthermore, lidocaine is utilized in the treatment of certain cardiac arrhythmias, particularly ventricular tachycardia and ventricular fibrillation, where it helps stabilize the cardiac membrane and restore normal rhythm.

In addition to its established uses, lidocaine has found applications in pain management strategies. Its topical formulations are often employed for conditions such as postherpetic neuralgia, diabetic neuropathy, and other chronic pain syndromes. The ability to deliver lidocaine directly to the site of pain through topical administration provides patients with effective pain relief while minimizing systemic exposure.

The discovery of lidocaine has also paved the way for further research into the development of new local anesthetics and modifications of existing compounds. Researchers have explored various derivatives of lidocaine to enhance its potency, duration of action, and safety profile. These advancements contribute to ongoing efforts to improve patient care and comfort during medical procedures.

Despite its widespread use, lidocaine is not without risks. Adverse effects may include allergic reactions, cardiovascular complications, and central nervous system toxicity, particularly when administered inappropriately or in excessive doses. Therefore, healthcare providers must be vigilant in monitoring patients during and after lidocaine administration to ensure safety and efficacy.

In summary, lidocaine stands as a cornerstone in the field of local anesthesia and pain management, owing to its rapid onset, effectiveness, and versatility. From its discovery in the 1940s to its current applications in various medical fields, lidocaine has significantly impacted patient care by providing effective pain relief and contributing to the safety of surgical and medical interventions.

References

1979. Penetration Enhancers and Other Factors Governing Percutaneous Local Anaesthesia with Lidocaine. Acta Pharmacologica et Toxicologica, 45(1).
DOI: 10.1111/j.1600-0773.1979.tb02361.x

1979. Therapeutic Blood Lidocaine Concentrations after Local Anesthesia for Cardiac Electrophysiologic Studies. The New England Journal of Medicine, 301(8).
DOI: 10.1056/nejm197908233010808

1979. Cytotoxic Effects of Procaine, Lignocaine and Bupivacaine. British Journal of Anaesthesia, 51(4).
DOI: 10.1093/bja/51.4.273