Lidocaine patches deliver pain relief directly to a specific body area. Containing lidocaine, a local anesthetic absorbed through the skin, they manage localized pain. They offer a targeted alternative to oral medications for certain conditions.
How Lidocaine Relieves Pain
Lidocaine functions as a local anesthetic by interfering with nerve cells’ pain signal transmission. Nerve cells generate electrical signals via sodium ion movement across their membranes, through specialized voltage-gated sodium channels.
When a nerve impulse is generated, sodium channels open, allowing sodium ions to flow into the nerve cell, a process called depolarization. Lidocaine works by physically binding to these sodium channels, effectively blocking the entry of sodium ions into the nerve cells.
By preventing this sodium influx, lidocaine stabilizes the nerve cell membrane, making it more difficult for the nerve to generate and transmit electrical impulses. This halts pain signals from reaching the brain, leading to localized numbing and pain relief. The patch concentrates this pain-blocking action where applied, minimizing systemic absorption.
Applying and Using the Patch
Proper application of a lidocaine patch is important for its effectiveness and safety. Before applying, the skin should be clean, dry, and free from cuts, irritation, or rashes. The patch is placed directly over the most painful area.
For prescription-strength patches, the typical duration of wear is up to 12 hours within a 24-hour period, followed by a 12-hour patch-free interval. Over-the-counter patches may have different instructions, worn for up to 8 hours. Do not exceed three patches at one time for prescription versions. If a smaller area needs treatment, the patch can be cut to size before removing the protective liner.
Conditions Treated by Lidocaine Patches
Lidocaine patches primarily alleviate localized pain, commonly prescribed for neuropathic pain from nerve damage. A prominent condition treated is post-herpetic neuralgia (PHN), persistent nerve pain after a shingles infection. Shingles, caused by the varicella-zoster virus, can damage nerve fibers, leading to ongoing pain even after the rash heals.
Lidocaine patches help manage the burning, stabbing, or aching sensations associated with PHN by directly targeting the overactive nerves in the affected skin area. Their localized action makes them suitable for pain that is sensitive to touch or occurs in a specific region. While PHN is a primary indication, lidocaine patches may also be used for other localized pain conditions where their numbing effect can provide relief.
Safety Considerations and Side Effects
While well-tolerated, lidocaine patches can cause side effects, most often at the application site. Common local reactions include redness, irritation, itching, or a burning sensation. These skin reactions are mild and temporary, resolving within a few minutes to hours after patch removal. If severe or persistent irritation occurs, the patch should be removed.
Systemic side effects are uncommon due to the minimal absorption of lidocaine into the bloodstream when used as directed. However, if too much lidocaine is absorbed, symptoms such as dizziness, lightheadedness, or drowsiness may occur. It is important to keep patches out of reach of children and pets, as ingestion or chewing can lead to serious adverse effects. Consulting a healthcare professional is advisable for specific medical advice, especially if other medications are being used.