lidocaine topical

Action and Spectrum

Actions and Spectrum: 

• lidocaine is a local anesthetic that blocks nerve impulses’ initiation and conduction. It does this by inhibiting the influx of sodium ions into the nerve cells, which are necessary for generating and propagating action potentials. 
• When applied topically, lidocaine is absorbed through the skin and into the underlying tissues, where it exerts its anesthetic effects. It is commonly used to relieve pain and discomfort caused by skin irritations, burns, or other injuries. 
• lidocaine is effective against various pain types, including neuropathic pain, postoperative pain, and musculoskeletal pain. It can also alleviate pain associated with specific medical procedures, such as venipuncture or wound debridement. 
• lidocaine has a broad spectrum of activity, making it useful in various medical settings. However, it is generally ineffective for treating pain that originates deep within the body, such as pain associated with internal organs or deep tissue injuries. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Urticaria 

Cutaneous lesions,  

Anaphylactoid reactions 

Edema 

Hypotension 

Bradycardia 

Cardiovascular collapse 

Central Nervous System Disorders: 

Apprehension 

Euphoria 

Dizziness 

Nervousness, 

Confusion 

Tinnitus 

Sensations of heat, cold, or numbness 

Tremors 

Lightheadedness 

Convulsions 

Respiratory depression and arrest 

Drowsiness 

Blurred or double vision 

Vomiting 

Twitching 

Unconsciousness 

Black Box Warning

Black box warning: 

lidocaine can cause serious side effects if misused or in excessive doses. Systemic toxicity, including seizures, respiratory depression, and cardiovascular collapse, can occur if too much lidocaine is absorbed into the bloodstream. 

Contraindication / Caution

Contraindications/caution: 

Contraindications: 

lidocaine topical should not be used in individuals with known hypersensitivity or allergy to lidocaine or other local anesthetics. Additionally, it should not be applied to broken or damaged skin or mucous membranes, as this may increase the risk of systemic absorption and toxicity. 

Other contraindications of lidocaine topical include: 

• Infections or open wounds in the area of application 
• Impaired liver function or severe hepatic disease 
• Porphyria is a rare genetic disorder that affects the production of heme in the body 
• Heart block or other serious heart conditions 
• Severe hypertension or hypotension 
• Use in neonates or premature infants, as they may be more sensitive to the effects of the medication. 

Caution: 

• Use caution in individuals with liver or kidney disease: lidocaine is metabolized by the liver and excreted by the kidneys. Individuals with impaired liver or kidney function may be at increased risk for adverse effects from lidocaine. 
• Avoid use on large areas of skin or for prolonged periods: Prolonged use of lidocaine on large areas of skin may increase the risk of systemic absorption and toxicity. 
• Use caution when applying to sensitive areas: lidocaine can cause irritation or burning when applied to sensitive areas such as the face or genitals. 
• Use caution in children: lidocaine should be used with caution in children, especially those under the age of 2, as they may be more sensitive to the effects of the medication. 
• Avoid use during pregnancy and breastfeeding: The safety of lidocaine during pregnancy and breastfeeding is not well established. It should be used only if the potential benefits outweigh the potential risks. 
• Interactions with other medications: lidocaine may interact with other medications, including other local anesthetics, antiarrhythmics, and beta blockers, and should be used with caution in individuals taking these medications. 

Pregnancy / Lactation

Pregnancy consideration: Insufficient data available 

Lactation:  

• Excretion of the drug in human breast milk is unknown 
• It should be used only if the potential benefits outweigh the potential risks. 

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 agent that works by blocking nerve impulses. When applied topically, lidocaine is absorbed through the skin and into the underlying tissues, where it exerts its anesthetic effects. 

• lidocaine works by blocking voltage-gated sodium channels in nerve cells. This prevents the influx of sodium ions, which are necessary for generating and propagating action potentials. By blocking nerve impulses, lidocaine reduces the sensation of pain and discomfort. 

Pharmacodynamics: 

• lidocaine topical is a local anesthetic that blocks nerve impulses in the application area. The pharmacodynamics of lidocaine topical involve its interaction with voltage-gated sodium channels, which generate and propagate action potentials in nerve cells. 

• lidocaine binds to and blocks these sodium channels, preventing the influx of sodium ions and thereby preventing the generation of action potentials. This results in a local loss of sensation, including pain, temperature, and touch. 

Pharmacokinetics: 

Absorption 

lidocaine topical is absorbed through the skin and into the underlying tissues. The rate and extent of absorption depend on the concentration of the medication, the area of application, and the duration of application. The onset of action for lidocaine topical is 3-5 minutes when applied as a gel, cream, or ointment. 

Distribution 

lidocaine is distributed throughout the body after absorption. The extent of distribution depends on various factors, including the dose, the route of administration, and the presence of tissue binding sites. lidocaine has a relatively small volume of distribution, which means it is primarily distributed in the extracellular fluid and has limited penetration into the central nervous system. 

Metabolism 

the liver rapidly metabolizes lidocaine into several metabolites, including MEGX and GX. These metabolites have pharmacologic activity like, but less potent than, that lidocaine. It is not known if lidocaine is metabolized in the skin. 

Elimination and Excretion 

The half-life of lidocaine following intravenous administration is 81-149 minutes. The total body clearance of lidocaine ranges from 0.33-0.9 L/min. lidocaine and its metabolites are primarily excreted by the kidneys, with less than 10% of the drug excreted unchanged in the urine. 

Adminstartion

Administration: 

lidocaine topical is a medication applied to the skin to produce local anesthesia. It is available in various forms, including gels, creams, ointments, patches, and sprays. Here are some general guidelines for the administration of lidocaine topical: 

• Clean the skin: Before applying topical lidocaine, clean the skin with soap and water, then dry it thoroughly. This helps to remove any dirt or oils that may interfere with the absorption of the medication. 
• Apply the medication: Apply a thin layer of lidocaine topical to the area where local anesthesia is desired. Be sure to cover the entire area evenly. 
• Massage the medication: Massage the medication into the skin until it is fully absorbed. This helps to increase the penetration of the medication into the underlying tissues. 
• Follow instructions: Follow the specific instructions provided with the medication regarding the duration of application, the frequency of application, and any other special precautions. 
• Avoid contact with eyes and mucous membranes: lidocaine topical should not be applied to the eyes or mucous membranes, as this can cause irritation and discomfort. 
• Wash hands after application: After applying lidocaine topical, wash your hands thoroughly with soap and water to remove residual medication. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: lidocaine topical 

Why do we use lidocaine topical? 

lidocaine topical medication produces local anesthesia or numbness in a specific body area. Here are some common uses of lidocaine topical: 

• Pain relief: lidocaine topical can temporarily relieve pain for minor burns, cuts, and insect bites. It can also relieve pain associated with arthritis, neuropathy, and post-herpetic neuralgia. 
• Local anesthesia: lidocaine topical can produce local anesthesia for minor surgical procedures, such as skin biopsies, suturing, and dental work. It can also be used for other medical procedures, such as catheter insertion or endoscopy. 
• Dermatological procedures: lidocaine topical can numb the skin before dermatological procedures, such as laser treatments, dermabrasion, and tattoo removal. 
• Cosmetic procedures: lidocaine topical can numb the skin before cosmetic procedures, such as Botox injections, dermal fillers, and chemical peels.