Lidocaine patches are a topical medication used for localized pain relief. They work by delivering lidocaine, a local anesthetic, directly to nerve endings in the skin, numbing the specific area. While typically associated with back pain or other musculoskeletal issues, their application on the chest is indicated for certain conditions, but requires careful consideration of safety and proper use.
Medical Conditions Treated on the Chest
For pain originating from nerve damage or localized trauma, a healthcare provider may prescribe or recommend lidocaine patches for use on the chest. Common conditions include:
- Postherpetic Neuralgia (PHN): This is a painful, nerve-related condition that can occur after a shingles outbreak. Shingles, caused by the varicella-zoster virus, often produces a rash on one side of the body, including the chest, and the resulting PHN can be treated with lidocaine patches.
- Post-Surgical Pain: After surgeries involving chest incisions, such as a sternotomy (for heart surgery) or thoracotomy (for lung surgery), lidocaine patches may be used as an adjunctive analgesic to manage incisional pain. Studies have shown they can reduce pain and the need for opioids in some patients.
- Post-Mastectomy Pain Syndrome (PMPS): Some breast cancer patients develop PMPS, a neuropathic pain condition following a mastectomy. Topical 5% lidocaine patches have shown effectiveness in managing this localized pain.
- Rib Fractures: Topical lidocaine has been studied as a non-invasive option for managing pain from traumatic rib fractures. While some studies show promising results in reducing pain and opioid use, especially in older patients, research is ongoing.
- Chest Wall Tumors: For localized neuropathic pain related to chest wall tumors, lidocaine patches have been used effectively as part of a pain management plan.
Important Safety Considerations
Using lidocaine patches on the chest or any other part of the body is not without precautions. The proximity to vital organs and the sensitivity of the skin require strict adherence to medical guidance.
Application on Intact Skin
Lidocaine patches should only be applied to clean, dry, intact skin. Applying them to broken, irritated, or inflamed skin can significantly increase the amount of lidocaine absorbed into the bloodstream, potentially leading to toxic levels.
Avoiding Systemic Toxicity
While systemic absorption is minimal when used correctly, excessive use or improper application can lead to a lidocaine overdose. Symptoms of overdose can include dizziness, blurred vision, numbness, confusion, or a slow heartbeat. To prevent this, never use more than the recommended number of patches or wear them for longer than the prescribed duration.
Danger of External Heat
Never apply external heat, such as a heating pad, electric blanket, or hot pack, over a lidocaine patch. Heat can accelerate the absorption of lidocaine, leading to dangerously high blood concentrations and an increased risk of serious side effects.
Risk of Methemoglobinemia
A rare but serious condition called methemoglobinemia has been reported with local anesthetic use, including lidocaine. It affects the blood's ability to carry oxygen and can be fatal if not treated promptly. Symptoms include pale, gray, or blue-colored skin, headache, rapid heart rate, and shortness of breath. Patients with pre-existing heart or lung problems, certain genetic deficiencies (e.g., G6PD), or infants are at higher risk.
Interaction with Other Medications
Inform your doctor and pharmacist of all prescription, over-the-counter, and herbal products you are taking. Certain medications, especially other local anesthetics or heart drugs like tocainide and mexiletine, can interact with lidocaine.
Comparing OTC and Prescription Patches
While both OTC and prescription lidocaine patches are available, they differ significantly in their formulation, strength, and intended use. Here is a comparison:
| Feature | OTC 4% Lidocaine Patches (e.g., Salonpas, Aspercreme) | Prescription 5% Lidocaine Patches (e.g., Lidoderm, ZTLido) |
|---|---|---|
| Strength | 4% Lidocaine | 5% Lidocaine |
| Availability | Over-the-counter at pharmacies | Requires a doctor's prescription |
| Primary Use | Temporary relief of minor pain from general causes like muscle aches, strains, or bruises | Specifically FDA-approved for relieving the nerve pain of postherpetic neuralgia |
| Application | Often recommended for a shorter duration, such as up to 8 hours | Applied to the painful area for up to 12 hours, followed by a 12-hour patch-free period |
| Customization | Can typically be cut to size | Can be cut to fit the affected area |
| Medical Supervision | Does not require a prescription, but medical consultation is recommended for chest pain | Requires a doctor's supervision due to higher concentration |
How to Apply a Lidocaine Patch on the Chest Safely
- Consult a Healthcare Provider: Always discuss the use of lidocaine patches on the chest with a doctor to determine if it is appropriate and safe for your specific condition.
- Choose the Correct Area: Apply the patch to the most painful, sensitive area. For nerve pain, this may be an area of skin that is unusually sensitive to touch.
- Prepare the Skin: Ensure the skin is clean, dry, and free of cuts, scrapes, or irritation.
- Cut to Fit (if necessary): If the painful area is small, you can cut the patch with scissors before removing the protective liner.
- Remove the Liner: Peel away the protective liner, avoiding touching the adhesive surface as much as possible.
- Apply Firmly: Press the patch firmly onto the skin to ensure good contact. Do not bandage it tightly.
- Follow the Schedule: Wear the patch for the prescribed time (e.g., 12 hours) and then remove it for the designated patch-free period. Use a new patch for each application.
- Dispose Properly: Fold used patches in half with the sticky side facing in. Discard them in a trash can where children and pets cannot reach them.
Conclusion
For certain neuropathic pain conditions, such as postherpetic neuralgia, post-thoracotomy pain, post-mastectomy pain, and rib fractures, a medical professional may advise using lidocaine patches on the chest. However, it is paramount to consult a doctor to determine the underlying cause of the chest pain before self-treating. Strict adherence to proper application techniques and dosage is essential to minimize the risk of serious side effects like systemic toxicity or methemoglobinemia. By following medical guidance, lidocaine patches can be a safe and effective component of a targeted pain management strategy.
For more detailed information on proper usage, you can refer to the MedlinePlus drug information page on Lidocaine Transdermal Patch.
