Lidocaine patches manage pain by delivering medication directly through the skin. They contain lidocaine, a local anesthetic that temporarily blocks nerve signals where applied. This reduces pain without affecting consciousness or causing widespread numbness.
Optimal Wearing Duration
Lidocaine patches have specific wearing durations for effectiveness and safety. For most prescription-strength lidocaine patches (5%), the recommended schedule involves wearing the patch for 12 hours, followed by a 12-hour patch-free interval. Over-the-counter (OTC) lidocaine patches, typically containing 4% lidocaine, may have slightly different instructions, often suggesting a wear time of 8 to 12 hours per application.
This 12-hour on/off cycle prevents excessive systemic absorption of lidocaine into the bloodstream. Continuous exposure beyond this period can lead to higher concentrations, increasing side effect risk. The patch-free interval also allows the skin to recover, reducing localized irritation, redness, or allergic reactions at the application site. Even during the 12-hour break, the medication continues to provide some pain relief due to its residual presence within the skin tissues.
Proper Application and Removal
Proper application ensures effectiveness and prevents skin irritation. Begin by ensuring the skin at the chosen application site is clean, dry, and intact. Avoid applying the patch to areas with open wounds, cuts, rashes, or irritated skin, as this can increase lidocaine absorption. Select an area with minimal hair for good adhesion; some prescription patches can be cut to fit the affected area.
Remove the backing and apply the adhesive side firmly to the skin, pressing for full contact. Wash hands thoroughly after application to remove residual medication. Gently peel off the patch when it’s time for removal.
Important Safety Precautions
Lidocaine patches are generally safe when used as directed, but require safety precautions. Common side effects often involve the application site, such as mild redness, burning, itching, or swelling. These reactions are usually temporary and resolve after the patch is removed.
More serious, less common systemic side effects can occur if too much lidocaine is absorbed. These can include dizziness, lightheadedness, headache, nausea, vomiting, or confusion. In rare instances, excessive absorption may lead to a serious blood disorder called methemoglobinemia, characterized by symptoms like pale, gray, or blue skin, headache, and shortness of breath. Seek immediate medical attention if you experience signs of a severe allergic reaction, such as hives, difficulty breathing, or swelling of the face, throat, or tongue.
Certain conditions and practices increase the risk of adverse effects. Individuals with a known allergy to lidocaine or other amide-type local anesthetics should not use these patches. Those with severe liver disease may be at higher risk due to reduced ability to process lidocaine.
Avoid applying heat sources, such as heating pads or electric blankets, directly over a lidocaine patch, as this can significantly increase medication absorption and raise the risk of systemic side effects. Do not use other lidocaine-containing products, like creams or gels, on the same area simultaneously without consulting a healthcare professional. Used patches still contain medication and should be folded sticky sides together and disposed of safely, out of reach of children and pets, to prevent accidental exposure.