General
Hepatic Disease
Patients with severe hepatic disease are at greater risk of developing toxic blood concentrations of
Lidocaine and menthol, because of their inability to metabolize lidocaine and menthol normally.
Allergic Reactions
Patients allergic to para-aminobenzoic acid derivatives (procaine, tetracaine, benzocaine, etc.) have not
shown cross sensitivity to lidocaine. However, Lidothol Gel should be used with caution in patients
with a history of drug sensitivities, especially if the etiologic agent is uncertain.
Although rare, get emergency medical help if you have signs of an allergic reaction from oral or topical application of menthol: hives, difficulty breathing, or swelling of your face, lips, tongue, or throat.
Non-intact Skin
Application to broken or inflamed skin, although not tested, may result in higher blood concentrations of lidocaine and menthol from increased absorption. Lidothol Gel is only recommended for use on intact skin.
External Heat Sources
Placement of external heat sources, such as heating pads or electric blankets, over Lidothol Gel
is not recommended as this has not been evaluated and may increase plasma lidocaine levels.
Eye Exposure
The contact of Lidothol Gel with eyes, although not studied, should be avoided based on the findings of
severe eye irritation with the use of similar products in animals. If eye contact occurs, immediately
wash out the eye with water or saline and protect the eye until sensation returns.
Information for Patients
Methemoglobinemia
Inform patients that use of local anesthetics may cause methemoglobinemia, a serious condition that must be treated promptly. Advise patients or caregivers to stop use and seek immediate medical attention if they or someone in their care experience the following signs or symptoms: pale, gray, or blue colored skin (cyanosis); headache; rapid heart rate; shortness of breath; lightheadedness; or fatigue.
Drug Interactions
Antiarrhythmic Drugs
Lidothol Gel should be used with caution in patients receiving Class I antiarrhythmic drugs (such as
tocainide and mexiletine) since the toxic effects are additive and potentially synergistic.
Local Anesthetics
When Lidothol Gel is used concomitantly with other products containing local anesthetic agents, the
amount absorbed from all formulations must be considered.
Drugs That May Cause Methemoglobinemia When Used with Lidothol Gel
Patients who are administered local anesthetics are at increased risk of developing methemoglobinemia
when concurrently exposed to the following drugs, which could include other local anesthetics:
Examples of Drugs Associated with Methemoglobinemia:
Class Examples
Nitrates/Nitrites nitric oxide, nitroglycerin, nitroprusside, nitrous oxide
Local anesthetics
articaine, benzocaine, bupivacaine, lidocaine, mepivacaine, prilocaine, procaine, ropivacaine, tetracaine
Antineoplastic agents cyclophosphamide, flutamide, hydroxyurea, ifosfamide, rasburicase, Antibiotics dapsone, nitrofurantoin, para-aminosalicylic acid, sulfonamides, Antimalarials chloroquine, primaquine Anticonvulsants Phenobarbital, phenytoin, sodium valproate, Other drugs acetaminophen, metoclopramide, quinine, sulfasalazine Carcinogenesis, Mutagenesis
Impairment of Fertility
The effect of Lidothol Gel on fertility has not been studied.
Pregnancy
Teratogenic Effects
Pregnancy Category B.
Lidothol Gel has not been studied in pregnancy.
Labor and Delivery
Lidothol Gel has not been studied in labor and delivery.
Nursing Mothers
Lidothol Gel has not been studied in nursing mothers.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.