Lidocaine patches are transdermal patches that deliver a local anesthetic directly through the skin. They provide targeted, temporary pain relief by releasing lidocaine to a specific area of the body. Their non-invasive nature and ease of application make them a convenient option for managing localized discomfort without injections or oral ingestion.
How Lidocaine Patches Relieve Pain
Lidocaine, the active ingredient, functions as a local anesthetic. When applied to the skin, it temporarily numbs nerve endings in the treated area. This numbing occurs because lidocaine interferes with the transmission of pain signals.
The mechanism involves blocking voltage-gated sodium channels within nerve cells. These channels are crucial for generating and transmitting electrical impulses, including pain signals, along nerve fibers. By binding to these channels, lidocaine prevents sodium ions from entering the nerve cells, which in turn suppresses the initiation and conduction of nerve impulses.
The effect is localized, providing relief only where the patch is applied. It does not provide systemic pain relief throughout the body, distinguishing it from oral pain medications.
Conditions Treated by Lidocaine Patches
A primary approved use for prescription-strength lidocaine patches is for post-herpetic neuralgia (PHN), nerve pain that can persist after a shingles infection. This condition often causes burning, stabbing pains or aches due to nerve damage.
These patches are also applied for other forms of localized neuropathic pain, which arises from nerve damage or dysfunction. Beyond nerve-specific pain, lidocaine patches can address localized musculoskeletal pain, such as discomfort in muscles or joints. They are utilized for general aches, minor burns, insect bites, and certain types of back pain.
For instance, they may be used for pain from a broken bone or discomfort following a fall. While some studies have explored their use for conditions like chronic low back pain and painful diabetic neuropathy, effectiveness can vary, and more research continues in these areas.
Safe and Effective Use of Lidocaine Patches
Before applying a patch, the skin should be clean, dry, and intact, free from cuts, rashes, or irritation. The patch should be placed directly over the painful area, and it can be cut to fit smaller or irregularly shaped areas if needed, while keeping the protective liner in place during cutting.
The duration of wear varies depending on the type of patch. Prescription-strength lidocaine patches are typically worn for up to 12 hours within a 24-hour period, followed by a 12-hour patch-free interval. Over-the-counter patches often have instructions for wear times ranging from 8 to 12 hours. It is important to remove the old patch before applying a new one.
Avoid applying patches to broken or irritated skin, as this can increase lidocaine absorption into the bloodstream, potentially leading to unwanted effects. It is also advisable to avoid applying heat, such as from heating pads or electric blankets, directly over the patch, as this can also increase drug absorption.
Common, mild side effects at the application site can include redness, itching, burning, or irritation. These reactions are usually temporary and often resolve within minutes to hours after patch removal. If severe irritation, blistering, or signs of an allergic reaction like hives or swelling occur, the patch should be removed immediately, and medical attention sought.
Consulting a healthcare professional is recommended to determine if lidocaine patches are appropriate for a specific condition. They can provide personalized instructions, especially concerning the number of patches to use and duration of wear. Proper disposal of used patches involves folding them sticky sides together and placing them out of reach of children and pets, as they may still contain residual medication.