Nerve pain, or neuropathic pain, is a persistent condition caused by damage or dysfunction within the nervous system. This damage leads to various uncomfortable sensations. Topical lidocaine is often considered for managing these specific types of pain. This article explains how lidocaine works and its role in treatment.
Understanding Nerve Pain
Neuropathic pain originates from damage or malfunction of the nervous system, affecting either peripheral nerves or the central nervous system, including the spinal cord and brain. This damage causes nerve fibers to send incorrect signals to pain centers.
Individuals experiencing nerve pain often describe sensations such as burning, stabbing, or electric shock-like feelings. Other common symptoms include tingling, numbness, or a “pins and needles” sensation. Heightened sensitivity to touch, where normally painless stimuli cause pain, can also occur.
How Lidocaine Alleviates Nerve Pain
Lidocaine is a local anesthetic that numbs a specific area, blocking nerve signals in the skin to prevent pain messages from reaching the brain. This targeted action reduces or eliminates pain sensation in the treated area.
Lidocaine interferes with electrical impulses along nerve cells by blocking voltage-gated sodium channels in their membranes. These channels are essential for sodium ion flow, which initiates nerve impulses. By inhibiting this influx, lidocaine stabilizes the nerve cell membrane, preventing pain signal transmission.
Nerve Pain Conditions Lidocaine Can Treat
Topical lidocaine is often utilized for specific types of localized nerve pain, providing targeted relief where it is applied. Lidocaine patches are frequently prescribed for post-herpetic neuralgia (PHN), which is chronic nerve pain that can persist after a shingles infection. For PHN, lidocaine works by reducing the abnormal excitability of damaged peripheral nerves and dampening central nervous system hyperexcitability.
Lidocaine may also be beneficial for certain types of diabetic neuropathy, particularly when the pain is localized. In diabetic neuropathy, nerve damage can lead to increased regulation of sodium channels in nerve cell membranes, contributing to spontaneous excitability and nerve hyperexcitability. Lidocaine’s ability to selectively block these sodium channels can help reduce neuronal discharge and alleviate pain in affected areas. Additionally, lidocaine can be used for localized nerve compression, such as carpal tunnel syndrome, where pressure on a nerve causes pain, tingling, or numbness.
Using Lidocaine for Nerve Pain
Lidocaine for nerve pain is available in various topical forms, including patches, creams, gels, and sprays, designed for direct application to the skin. Patches are a common option, with both prescription (e.g., 5% lidocaine) and over-the-counter (e.g., 4% lidocaine) strengths available. These formulations deliver lidocaine locally to the affected area, minimizing systemic absorption.
To use lidocaine patches, they are typically applied to clean, dry, intact skin over the most painful area. Depending on the specific product, patches may be worn for a set duration, often up to 8 or 12 hours within a 24-hour period. Creams, gels, and sprays are applied directly to the skin as directed, with usage frequency varying by product. It is important to carefully follow the instructions provided with the product or by a healthcare professional to ensure proper and safe application.
Important Considerations When Using Lidocaine
Lidocaine is generally safe, but important considerations apply. Common side effects are typically localized to the application site and can include skin irritation, redness, itching, or a burning sensation. If irritation occurs, the product should be removed, and reapplication should be avoided until the irritation subsides.
Systemic absorption of lidocaine is usually low with topical application, but applying it to broken or irritated skin, over large areas, or using excessive amounts can increase absorption and the risk of more serious side effects. These rare but severe reactions can include dizziness, confusion, headache, or heart-related issues. A rare blood disorder called methemoglobinemia is also a potential, though uncommon, risk, particularly in infants under six months or those with certain genetic conditions. It is advisable to consult a healthcare professional before using lidocaine, especially if there are underlying heart or liver conditions, or if pregnant or breastfeeding. Lidocaine is generally considered safe for use during pregnancy and breastfeeding, though medical supervision is recommended. It is also important to recognize that lidocaine may not be effective for all types or severities of nerve pain, and its efficacy can vary among individuals.