lidocaine anesthetic

Action and Spectrum

Actions and Spectrum: 

• lidocaine is a local anesthetic that blocks the initiation and conduction of nerve impulses in a specific area of the body. Lidocaine works by inhibiting the voltage-gated sodium channels in nerve cell membranes, which are responsible for the initiation and conduction of nerve impulses. By blocking these channels, lidocaine prevents the nerves from sending signals of pain and discomfort to the brain. 

• lidocaine has a broad spectrum of activity, making it practical for various medical and dental procedures. It is commonly used for topical anesthesia, infiltration anesthesia, nerve block anesthesia, and epidural anesthesia. lidocaine can also treat certain arrhythmias, or irregular heartbeats, by blocking the electrical signals that cause them. 

• lidocaine is effective for sensory and motor nerves, making it useful for various procedures, including surgeries, dental work, and dermatological procedures. It is also commonly used to relieve pain associated with shingles, post-herpetic neuralgia, and other chronic pain conditions. lidocaine is generally well-tolerated but can cause side effects like all medications. These may include numbness, tingling, and allergic reactions in some patients. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Bradycardia 

Edema 

Heart block 

Agitation 

Confusion 

Dizziness 

Euphoria 

Arrhythmias 

Cardiovascular collapse 

Hypotension 

Apprehension 

Coma 

Drowsiness 

Disorientation 

Lightheadedness 

Paresthesia 

Sensations of heat, cold, or numbness 

Seizures 

Tremulousness 

Visual disturbances, including blurred or double vision 

Urticaria 

Difficulty swallowing 

Vomiting 

Dyspnea 

Nervousness 

Slurred speech 

Tinnitus 

Unconsciousness 

Skin lesions 

Anaphylactoid reactions 

Nausea 

Muscle twitching/ tremors 

Respiratory depression/arrest 

Psychosis 

Administration Effects 

intramuscular injection increases serum creatine kinase 

pain at the intramuscular injection site 

Black Box Warning

Contraindication / Caution

Contraindications/caution: 

Contraindications: 

• Allergy: Individuals allergic to lidocaine or any of its components should not use this medication. 

• Severe heart block or heart failure: lidocaine can have adverse effects on the heart and should not be used in individuals with severe heart block or heart failure.

• Hepatic or renal dysfunction: lidocaine is metabolized in the liver and excreted by the kidneys. Individuals with hepatic or renal dysfunction may experience a buildup of lidocaine in their system, which can lead to toxic effects. 

• Pregnancy and breastfeeding: lidocaine should be used cautiously during pregnancy and breastfeeding, as it can cross the placenta and pass into breast milk.

• Neurological disorders: lidocaine can adversely affect the nervous system and should not be used in individuals with certain neurological disorders, such as myasthenia gravis or epilepsy. 

• Infection: lidocaine should not be injected into infected tissues, as it can worsen the infection and spread the bacteria. 

Caution: 

• Cardiovascular disease: lidocaine can adversely affect the heart and should be used cautiously in individuals with cardiovascular disease. 

• Hypotension: lidocaine can cause a drop in blood pressure, mainly when used in larger doses. It should be used with caution in individuals with hypotension. 

• Central nervous system depression: lidocaine can have a soothing effect on the central nervous system and cause dizziness, drowsiness, and confusion in some individuals. It should be used cautiously in individuals operating heavy machinery or driving. 

• Use in children: lidocaine should be used cautiously, as they may be more sensitive to its effects. 

• Use in elderly patients: lidocaine should be used with caution in elderly patients, as they may be more sensitive to its effects and more likely to experience adverse reactions. 

• Drug interactions: lidocaine can interact with other medications, such as beta-blockers and antiarrhythmic drugs, and should be used cautiously in individuals taking these medications. 

Pregnancy / Lactation

Pregnancy consideration: B 

Lactation:  

• Excretion of the drug in human breast milk is known 
• lidocaine should be used cautiously during breastfeeding, as it can cross the placenta and pass into breast milk. 

Pregnancy category: 

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.   

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category 

Pharmacology

Pharmacology: 

lidocaine is a local anesthetic that works by blocking voltage-gated sodium channels in the membranes of nerve cells. This action prevents the initiation and propagation of nerve impulses in a specific area of the body, leading to local anesthesia. 

Pharmacodynamics: 

• The pharmacodynamics of lidocaine involves its ability to block voltage-gated sodium channels in the membranes of nerve cells, leading to a reduction in nerve impulse transmission and the development of local anesthesia. 
• Voltage-gated sodium channels initiate and propagate action potentials in nerve cells. lidocaine blocks these channels by binding to the intracellular portion of the channel, preventing sodium ions from entering the cell and depolarizing the membrane. 
• The blockade of sodium channels by lidocaine leads to a reduction in the excitability of nerve cells and a decrease in the rate of action potential propagation. This results in local anesthesia, characterized by a loss of sensation and numbness in the area surrounding the administration site. 

Pharmacokinetics: 

Absorption 

lidocaine can be administered via various routes, including topical, transdermal, injectable, and oral routes. The absorption of lidocaine depends on the route of administration, with topical and transdermal formulations having slower and less predictable absorption than injectable formulations. Oral formulations of lidocaine have poor bioavailability due to extensive first-pass metabolism in the liver. 

Distribution 

After absorption, lidocaine is distributed throughout the body. lidocaine has a high affinity for binding to plasma proteins, particularly alpha-1 acid glycoprotein (AAG) and albumin. The volume of distribution of lidocaine can vary depending on the formulation and route of administration, with a volume of distribution of 0.7-2.7 L/kg for the patch formulation. 

Metabolism 

The cytochrome P450 enzyme system primarily metabolizes lidocaine in the liver, specifically the CYP3A4 and CYP1A2 isoforms. The primary metabolites of lidocaine are monoethylglycinexylidide (MEGX) and glycinexylidide (GX), less active than lidocaine. MEGX and GX are further metabolized by hydrolysis and excreted in the urine. 

Elimination and Excretion 

lidocaine and its metabolites are excreted primarily in the urine, with a small amount excreted in feces. The elimination half-life of lidocaine can vary depending on the dose and route of administration, with an initial half-life of 7-30 minutes and a terminal half-life of 1.5-2 hours. lidocaine clearance is affected by factors such as liver and kidney function, age, and co-administration of other medications. 

Adminstartion

Administration: 

lidocaine can be administered via several routes, including topical, transdermal, injectable, and oral routes. The administration route of lidocaine depends on the intended use and the patient’s medical condition. Here is a brief overview of the administration of lidocaine for different purposes: 

• Topical administration: lidocaine is available in topical formulations, such as creams, gels, and sprays, for local anesthesia. These formulations are applied directly to the skin or mucous membrane to provide local anesthesia. The duration of action depends on the formulation and the site of administration. 

• Transdermal administration: lidocaine is also available in transdermal patches, which are applied to the skin to manage post-herpetic neuralgia (PHN) or chronic pain. The patch slowly releases lidocaine into the bloodstream, providing prolonged pain relief. 

• Injectable administration: lidocaine is available in injectable formulations, including solutions and suspensions, for regional anesthesia and nerve block. The dose and concentration of lidocaine depend on the intended use and the patient’s medical condition. 

• Oral administration: lidocaine is also available in oral formulations, including solution and capsule, for treating arrhythmias and as an anti-reflux medication. Oral lidocaine has poor bioavailability due to extensive first-pass metabolism in the liver and is primarily used in the hospital setting. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: lidocaine anesthetic 

Why do we use lidocaine anesthetic 

lidocaine is a local anesthetic that is widely used for various medical purposes. Here are some of the common uses of lidocaine: 

• Local anesthesia: lidocaine is commonly used to provide local anesthesia for minor surgical procedures, dental work, and other medical procedures. Topical lidocaine formulations, such as creams and gels, numb the skin or mucous membrane before the procedure. 
• Nerve block and regional anesthesia: lidocaine is used as a nerve block or regional anesthesia for surgical procedures that require a larger area of anesthesia. This may include epidural anesthesia, spinal anesthesia, or peripheral nerve blocks. 
• Pain management: lidocaine is also used for pain management, particularly for chronic conditions such as post-herpetic neuralgia (PHN) and neuropathic pain. lidocaine can be administered via transdermal patches, which provide long-lasting pain relief. 
• Cardiac arrhythmias: lidocaine treats cardiac arrhythmias, particularly ventricular arrhythmias, as it stabilizes the heart rhythm. 
• Gastrointestinal disorders: lidocaine can also treat certain gastrointestinal disorders, such as gastroesophageal reflux disease (GERD) and functional dyspepsia, by reducing esophageal sphincter pressure gastric motility. 
• Allergy testing: lidocaine can be used during skin allergy testing to reduce the pain and discomfort associated with the test.