ztlido

Important safety information

Accidental Exposure : Even a used ZTLIDO topical system contains residual lidocaine after use. It is important for patients to store and dispose of ZTLIDO properly and keep out of the reach of children, pets, and others. ( 5.1 ) Excessive Dosing/Overexposure : Applying ZTLIDO to larger surface areas or for a longer duration than recommended could lead to increased absorption and high blood concentrations of lidocaine, leading to adverse effects. ( 5.2 ) Increased Absorption on Non-Intact Skin : May result in higher blood concentrations of lidocaine. ( 5.2 ) Risk of Overexposure with External Heat Sources : Applying external heat sources to ZTLIDO may result in increased drug exposure. ( 5.2 ) Methemoglobinemia : Cases of methemoglobinemia have been reported in association with local anesthetic use. ( 5.3 ) Application Site Reactions : During or immediately after treatment with ZTLIDO, application site reactions may develop. ( 5.4 ) Hypersensitivity Reactions : Cross sensitivity to ZTLIDO in patients with a history of drug sensitivity to para-aminobenzoic acid (PABA) derivatives is possible. ( 5.5 ) Eye Exposure : Immediately wash out the eye with water or saline and protect the eye until sensation returns. ( 5.6 ). 5.1 Accidental Exposure A used ZTLIDO topical system contains residual lidocaine after use. The potential exists for a small child or a pet to suffer serious adverse effects from chewing or ingesting a new or used ZTLIDO. It is important for patients to store and dispose of ZTLIDO properly, and keep out of the reach of children, pets, and others [see Dosage and Administration (2.1) ]. 5.2 Excessive Dosing/Overexposure to Lidocaine Lidocaine toxicity can be expected at lidocaine blood concentrations above 5 mcg/mL. The blood concentration of lidocaine is determined by the rate and extent of lidocaine absorption and elimination. Longer duration of application, application of more than the recommended number of ZTLIDO, smaller patients, or impaired elimination may all contribute to increasing the blood concentration of lidocaine. If lidocaine overdose is suspected, check drug blood concentration. Management of overdose includes close monitoring, supportive care, and symptomatic treatment [see Overdosage (10) ] . Improper Application and Duration of Use : Application of more than the recommended number of ZTLIDO or applying ZTLIDO for longer than the recommended wearing time (12 hours of every 24 hours) could result in increased absorption and high blood concentrations of lidocaine, leading to adverse reactions. Advise patients on proper application and duration. Hepatic Disease : Impaired elimination may contribute to increasing blood concentrations of lidocaine. Patients with severe hepatic disease are at greater risk of developing toxic blood concentrations of lidocaine because of their inability to metabolize lidocaine normally. Use on Non-Intact Skin : Application to broken or inflamed skin, although not tested, may result in higher blood concentrations of lidocaine from increased absorption. ZTLIDO is only recommended for use on intact skin. Advise patients not to apply ZTLIDO to non-intact skin. External Heat Sources : External heat sources may increase drug exposure, leading to overexposure to lidocaine. Advise patients not to apply external heat sources to ZTLIDO during administration [see Clinical Pharmacology (12.3) ]. 5.3 Methemoglobinemia Cases of methemoglobinemia have been reported in association with local anesthetic use. Although all patients are at risk for methemoglobinemia, patients with glucose-6-phosphate dehydrogenase deficiency, congenital or idiopathic methemoglobinemia, cardiac or pulmonary compromise, infants under 6 months of age, and concurrent exposure to oxidizing agents or their metabolites are more susceptible to developing clinical manifestations of the condition. If local anesthetics must be used in these patients, close monitoring for symptoms and signs of methemoglobinemia is recommended. Signs of methemoglobinemia may occur immediately or may be delayed some hours after exposure, and are characterized by a cyanotic skin discoloration and/or abnormal coloration of the blood. Methemoglobin levels may continue to rise; therefore, immediate treatment is required to avert more serious central nervous system and cardiovascular adverse effects, including seizures, coma, arrhythmias, and death. Discontinue ZTLIDO and any other oxidizing agents. Depending on the severity of the signs and symptoms, patients may respond to supportive care, i.e., oxygen therapy, hydration. A more severe clinical presentation may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. 5.4 Application Site Reactions During or immediately after treatment with ZTLIDO, the skin at the site of application may develop blisters, bruising, burning sensation, depigmentation, dermatitis, discoloration, edema, erythema, exfoliation, irritation, papules, petechia, pruritus, vesicles, or may be the locus of abnormal sensation. These reactions are generally mild and transient, resolving spontaneously within a few minutes to hours. If application site reactions occur while the topical system is being worn, advise the patient to remove ZTLIDO and not to reapply until skin reactions subside. 5.5 Hypersensitivity Reactions Patients allergic to para-aminobenzoic acid (PABA) derivatives (procaine, tetracaine, benzocaine, etc.) have not shown cross-sensitivity to lidocaine. However, be aware of the potential for cross-sensitivity in patients allergic to PABA derivatives, especially if the etiologic agent is uncertain. Manage hypersensitivity reactions by conventional means. The detection of sensitivity by skin testing is of doubtful value. 5.6 Eye Exposure The contact of ZTLIDO with eyes, although not studied, should be avoided based on findings of severe eye irritation with the application of similar products in animals. If eye contact occurs, immediately wash out the eye with water or saline and protect the eye (such as, eye glasses/eye wear) until sensation returns.