Lidocaine patches deliver anesthetic medication through the skin. The patch may improve back pain, but research is limited about how well the patch works. The patch also has a range of potential side effects.

Older research suggests that 5% lidocaine patches may significantly reduce lower back pain.

This article discusses the lidocaine patch for back pain, including how it works, the dosage, safety instructions, and side effects. It also explains when to call a doctor in the event of an overdose.

A person applying a lidocaine patch.Share on Pinterest
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Prescription-strength lidocaine patches are adhesive fabric patches that contains a 5% solution of the local anesthetic lidocaine. A person can also buy lidocaine 4% patches over the counter.

Lidocaine patches stick to the skin and slowly deliver the medication, which stops nerve cell pain signals from reaching the brain.

The Food and Drug Administration (FDA) has approved lidocaine 5% patches for the treatment of postherpetic neuralgia. This is a complication of shingles that affects the skin and nerve fibers.

However, research suggests that these patches may be effective for other types of pain, including diabetic peripheral neuropathy, carpal tunnel syndrome, osteoarthritis, and chronic lower back pain.

Lidocaine binds to and blocks voltage-gated channels, or proteins, in the nerve cell membrane, which enable the passage of sodium ions.

Because these channels are responsible for initiating and transmitting nerve impulses, blocking them suppresses these actions. This results in reversible numbing of a specific part of the body.

An older 2004 study evaluated the effectiveness of the lidocaine patch on 71 people with moderate-to-severe low back pain. After 2 and 6 weeks of treatment, the results indicated that the patch significantly decreased pain intensity.

A 2021 review found evidence in favor of using lidocaine to manage chronic lower back pain. However, the authors noted that many of the studies had limitations and that more research is necessary to explore the effectiveness of lidocaine for back pain.

If a person’s back pain is a result of inflammation, lidocaine may not be as effective. The authors of a 2021 overview of the medication note that this may be because inflammation can reduce the concentration of lidocaine due to increased blood flow or because of an inflammation-induced increase of certain ions that interact with sodium ions.

A person should not rely on lidocaine alone to manage or treat back pain. A person should work with a doctor to determine the cause of back pain and discuss their options for treatment and symptom management.

Within a 24-hour period, people may apply up to three 5% patches for up to 12 hours. A person should apply each patch only once.

A person should not exceed the recommended dosage. If they are using other products that contain local anesthetic ingredients alongside lidocaine, they should consider the total dose they will be getting from all the products.

A person can speak with a doctor about how many patches they should use.

The instructions below indicate how a person can safely use lidocaine for back pain.

Application

To apply the patch:

  1. Wash hands.
  2. Cut off any hairs in the application area using scissors, but do not shave them.
  3. If the application area is small, cut the patch to size before removing the release liner.
  4. Apply the patch to dry skin that is free of cuts and spots.
  5. Wash hands again.

People should also be aware of the following guidelines on using the patch:

  • Do not apply the patch on unhealed shingles blisters, on an open wound, or on the mouth or eyes.
  • Remove the patch if a rash, itching, irritation, or burning occurs.
  • Do not use the patch alongside an external source of heat, such as an electric blanket or heating pad.
  • Avoid water contact with the patch, as it may not stick properly. Schedule showers, baths, and swimming for times when not wearing the patch.

Duration

To avoid exceeding the recommended dose, follow these directions:

  • Apply the patches only once per 24-hour period. It is permissible to leave the patches on for up to 12 hours.
  • If someone forgets to remove the patches after 12 hours, they should immediately remove them once they remember.

Removal

To remove and dispose of lidocaine patches:

  1. Take the patch off the skin, fold it in half with the sticky sides together, and throw it away.
  2. Keep the patches out of reach of children and pets. Chewing or swallowing lidocaine patches could cause serious side effects, as used lidocaine patches can still contain large amounts of anesthetic.
  3. Do not reuse a patch.
  4. Wash hands after removing and disposing of the patch.

Lidocaine patches can cause side effects that manifest at the application site and throughout the body (systemically).

Application site side effects

These effects usually disappear within a few minutes to hours. Effects may include:

Systemic side effects

Users have also reported systemic side effects, including:

Additionally, an allergic reaction or anaphylaxis may happen, although it is rare. Symptoms include:

Lidocaine also carries a risk of methemoglobinemia, a condition in which the tissues do not receive enough oxygen. This can cause:

A person should not apply lidocaine patches to broken skin, as doing so may result in higher blood concentrations of the drug.

People with severe liver conditions have a higher risk of developing a toxic buildup of lidocaine in their blood because the liver cannot metabolize it well.

Additionally, people who are pregnant or breastfeeding should consult a doctor before using lidocaine, because not much research has investigated lidocaine’s safety in these cases. Lidocaine can be present in breast milk.

A lidocaine overdose can affect the heart muscle and brain and lead to dramatic changes in a person’s pulse, breathing rate, and blood pressure.

A severe overdose is life threatening.

If someone experiences severe side effects, they should seek immediate medical advice.

However, because toxic lidocaine effects may progress, people should go to an emergency room immediately if they have any doubt about the severity of their symptoms.

The lidocaine patch for back pain is a sticky fabric patch a person can apply to their skin at the site of pain. It works by blocking pain signals from reaching the brain.

Some scientific evidence supports its effectiveness, but recent and high quality research is limited.

Many side effects from lidocaine patches are mild and do not last long. However, there is a risk of serious adverse effects.

Individuals with back pain should work with a doctor to find the cause of their pain and choose an appropriate treatment.

A person should seek immediate medical advice if they experience severe reactions to lidocaine patches.