Lidocaine patches are used for treating an outbreak of shingles (herpes zoster). They block the pain caused by numbing the area that’s affected. Hence, they are also referred to as a local anesthetic. In this article, we talk about the usage and side effects of these patches.
A lidocaine patch is nothing but a topical adhesive strip that contains 5% lidocaine. This lidocaine is applied to a non-woven polyester felt backing, and is then covered with a polyethylene terephthalate (PET) film release liner. It is present in an aqueous base that may also contain many other ingredients, like gelatin, glycerin, kaolin, tartaric acid, etc.
When you want to use a patch, ensure that it is applied to only intact skin and over the most painful area. So, first clean the area of the skin where you intend to place it. Then remove the protective liner, and apply the patch to the skin to cover the most painful area. You can apply up to three in a day, or as directed by your physician. However, make sure that you do not leave one on, for longer than twelve hours.
If the area of application is small, then you may cut the patch. Ensure that you cut it before removing the liner though. If you feel any kind of irritation or a burning sensation, remove it and do not reapply it, until the irritation is gone. If the irritation still persists, then ask your physician for an alternative. As mentioned before, ensure that you apply this product only to intact, non-irritated, and non-infected skin. Avoid contact with eyes, open wounds, or mucous membranes at any cost. If any eye contact does occur, wash your eyes immediately with water, and protect it until the sensation is gone.
Although the use of these patches for pain is a popular option, there are certain points that one needs to keep in mind. Firstly, when it is applied at the site of application, there may be development of blisters, bruising, a burning sensation, depigmentation, dermatitis, the formation of vesicles or papules, erythema, etc. These are mostly transient in nature, and resolve within little time after application. There is also a chance that a person has a true allergy to these patches. In such cases, a person may develop anaphylactoid reactions like angioedema, dyspnea, urticaria, pruritus, bronchospasm, and shock.
It is very rare that a person develops systemic side effects due to the patch. This is because the amount of lidocaine absorbed through the skin is relatively less. However, in some rare cases, a person may develop adverse reactions like those that are seen in case of use of other local anesthesia aids. These symptoms include CNS excitation or depression, confusion, dizziness, drowsiness, nervousness, apprehension, convulsions, tremors, numbness, twitching, etc. Sometimes, there may even be cardiovascular manifestations like bradycardia and hypotension, which could be dangerous.
There are a few other uses of these patches as well. Back pain and muscle pain are also said to be treated with their help. Although this treatment is only symptomatic, the best way to deal with back pain is to treat the underlying root cause. One of the largest hindering factors for using these patches is the cost. It could go up to USD 200 for a pack of thirty! However, more than anything, it is best to ask your health care provider before using these patches, to see whether they are indicated for your case of pain or not.
Disclaimer: This article is for informative purposes only, and should not be used as a replacement for expert medical advice.