Overview
Lidothol is a prescription topical patch, packaged with 15 medicated patches: 5 per re-sealable pouch, 3 pouches. Lidocaine is present in a 4% concentration (w/w). It is chemically designated as 2-‐(diethylamino)-‐N-‐(2,6-‐ dimethylphenyl) acetamide and has an empirical formula of C14H22N2O. The molecular weight of Lidocaine is 234.34 g/mol. Menthol is present in a 1% concentration (w/w).
Mechanism of Action
Lidocaine is a topical anesthetic and stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby effecting local anesthetic action. Menthol has local anesthetic and counterirritant qualities. It also acts as a weak kappa (ĸ) opioid receptor agonist. Menthol chemically triggers the cold-‐sensitive TRPM-‐8 receptors in the skin, which are responsible for the well-‐documented cooling sensation that occurs when applied to the skin. Menthol’s analgesic properties are not fully understood; however, they are mediated through a selective activation of ĸ-‐opioid receptors. Menthol also blocks voltage-‐sensitive sodium channels, reducing neural activity that may stimulate muscle tissue.
Indications
- Lidothol is a formulation used to assist patients in the treatment of mild to moderate acute or chronic aches or pain. Muscle or joint pain can be due to muscle or ligament strains, simple backache, tendonitis, osteoarthritis, rheumatoid arthritis, peripheral neuropathies such as diabetic neuropathy or post herpetic neuralgia, and other complex regional pains. It can also be used to help with certain types of headaches, but use with caution when applying in order to avoid eye contact. Other uses may be considered if deemed clinically relevant.
Common Doses
- Refer to label
Dosage
Apply Lidothol to intact skin to cover the most painful area. Apply no more than four patches per day. Each patch should not be applied for more than 12 hours in a given 24-‐ hour period. Patches may be cut into smaller sizes with scissors prior to removal of the protective film. Clothing may be worn over the area of application. Smaller areas of treatment are recommended in a debilitated patient, or a patient with impaired elimination. If irritation or a burning sensation occurs during application, remove the patch and do not reapply until the irritation subsides.
Contraindications
- Lidothol is contraindicated in patients with a known history of sensitivity to local anesthetics of the amide type, or to any other component of the product.
Side Effects
- The most common adverse reactions occur at the application site, including dermatitis, itching or scaling. These tend to be dose-‐limiting and diminish with time. Serious adverse experiences following the administration of Lidothol are similar in nature to those observed in other amide anesthetic-‐containing agents. These adverse experiences are, in general, dose-‐related and may result from high plasma levels caused by excessive dosage, rapid absorption, or may result from hypersensitivity, idiosyncrasy, or a diminished tolerance on the part of the patient.
Interactions
- Patients that are administered local anesthetics may be at increased risk of developing methemoglobinemia when concurrently exposed to the following oxidizing agents Class Nitrates/Nitrites Local Anesthetics Antineoplastic agents Antibiotics Antimalarials Anticonvulsants Other drugs Examples nitroglycerin, nitroprusside, nitric oxide, nitrous oxide benzocaine, lidocaine, bupivacaine, mepivacaine, tetracaine, prilocaine, procaine, articaine, ropivacaine cyclophosphamide, flutamide, rasburicase, ifosfamide, hydroxyurea dapsone, sulfonamides, nitrofurantoin, para-aminosalicyclic acid...