Lidocaine is a local anesthetic that provides localized pain relief by temporarily numbing specific areas. Arthritis, a condition characterized by joint inflammation, often results in persistent pain. Understanding how lidocaine interacts with the body’s pain pathways is important for determining its suitability as a pain management option for individuals with arthritis.
How Lidocaine Works
Lidocaine works by altering nerve signal conduction, thereby numbing the sensation of pain in a targeted area. It stabilizes the neuronal membrane, inhibiting the ionic fluxes necessary for electrical impulses along nerve fibers.
Specifically, lidocaine blocks voltage-gated sodium channels on nerve cell membranes. By binding to these channels, lidocaine prevents sodium ions from flowing into the nerve cell, stopping nerve impulses.
When nerve signals are blocked, the brain does not receive pain messages from the affected area. This results in numbing and temporary pain reduction where applied. The effect is temporary and does not cause permanent nerve damage, allowing pain relief without causing unconsciousness, unlike general anesthetics.
Applying Lidocaine for Arthritis Pain
Lidocaine is available in various topical forms, including creams, gels, and patches, applied directly to the skin over an affected joint for targeted arthritis pain relief. Over-the-counter lidocaine products typically contain up to 4% lidocaine, while prescription-strength versions can contain up to 5% or more.
When applied, lidocaine is absorbed through the skin, blocking nerve signals near the surface. This can be beneficial for localized, superficial arthritis pain, such as that experienced in the hands, knees, elbows, or ankles. For example, some studies indicate that 5% lidocaine patches can reduce pain intensity in patients with moderate-to-severe knee osteoarthritis.
While lidocaine can provide relief for minor joint and muscle soreness, its ability to alleviate deep or widespread arthritis pain may be limited. Since it primarily works by blocking signals at nerve endings in the skin, it may not penetrate deeply enough to affect pain originating from within the joint itself. Therefore, expectations regarding its effectiveness should be managed, particularly for severe or deeply seated pain.
Lidocaine patches release medication slowly into the skin over an extended period, providing relief for several hours. Over-the-counter patches can be worn for up to 8 hours, while prescription patches may be used for up to 12 hours within a 24-hour period. This sustained release is convenient for persistent localized pain.
Important Safety Information
Adhere to recommended dosages and application instructions for topical lidocaine to minimize side effects. Common mild reactions at the application site include temporary irritation, redness, itching, or a burning sensation. If these symptoms become bothersome or do not resolve, it is advisable to remove the product.
Applying lidocaine to broken, irritated, or damaged skin, such as cuts, rashes, or severe burns, can increase the amount of medication absorbed into the bloodstream, raising the risk of systemic side effects. Similarly, covering the treated area with bandages or applying heat, such as from heating pads or electric blankets, can accelerate absorption and increase the chance of adverse reactions.
Although rare with proper topical use, excessive absorption of lidocaine can lead to more serious systemic side effects. These can include dizziness, drowsiness, confusion, visual disturbances, ringing in the ears, or speech difficulties. In more severe cases, symptoms such as muscle twitching, seizures, or irregular heart rhythms may occur. A serious blood disorder called methemoglobinemia, where the blood’s ability to carry oxygen is impaired, is also a rare but possible side effect.
It is important to consult a healthcare professional if pain persists or worsens, or if any severe side effects develop. Seeking immediate medical attention is necessary for symptoms like chest tightness, difficulty breathing, swelling of the face or throat, or signs of an allergic reaction. Always keep lidocaine products out of reach of children and pets, as accidental ingestion or exposure, especially to patches, can be harmful.