SUMMARY PRODUCT INFORMATION

Last updated on RxList: 5/8/2008

Adults ( > 18 years of age):

XYLOCAINE Viscous 2% (lidocaine hydrochloride) is indicated to provide relief of pain and discomfort in connection with:

• Irritated or inflamed mucous membranes of the mouth and pharynx, e.g. lesions following tonsillectomy;
• Introduction of instruments and catheters into the respiratory and digestive tracts, e.g. bronchoscopy, esophagoscopy;
• Painful diseases of the upper gastrointestinal tract e.g. esophagitis.

Geriatrics ( > 65 years of age)

Elderly patients should be given reduced doses commensurate with their age and physical condition (see DOSAGE AND ADMINISTRATION-Special Populations).

Pediatrics ( < 18 years of age)

Children should be given reduced doses commensurate with their age, weight and physical condition (see DOSAGE AND ADMINISTRATION-Special Populations).

Lidocaine should be used with caution in children younger than two years of age as there are insufficient data to support the safety and efficacy of this product in this patient population at this time (see WARNINGS AND PRECAUTIONS-Special Populations).

Dosing Considerations

General

When XYLOCAINE Viscous 2% (lidocaine hydrochloride) is used concomitantly with other products containing lidocaine, the total dose contributed by all formulations must be kept in mind.

The degree of absorption from mucous membranes is variable but especially high from the bronchial tree. The degree of systemic absorption depends on whether the lidocaine viscous is swallowed or expectorated. It is therefore important to expectorate in order to avoid unnecessary absorption. After a swallowed single dose of 300 mg (15 mL) of lidocaine viscous, the resulting blood concentrations are low.

Special Populations

Lidocaine should also be used with caution in patients with epilepsy, impaired cardiac conduction, bradycardia, impaired hepatic or renal function and in severe shock (See WARNINGS AND PRECAUTIONS).

Debilitated, elderly patients, acutely ill patients, patients with sepsis, and children should be given reduced doses commensurate with their age, weight and physical condition.

XYLOCAINE Viscous 2% should be used with caution in children under the age of 2 as there is insufficient data to support the safety and efficacy of this product in this patient population at this time.

Mode of Administration

Xylocaine Viscous 2%

XYLOCAINE VISCOUS 2% IS FOR TOPICAL USE ONLY AND MUST NOT BE USED FOR INJECTION (see WARNINGS AND PRECAUTIONS).

For oral analgesia, the solution should be swished around in the mouth and spat out or swallowed slowly.

For use in the pharynx, the solution should be gargled and may be swallowed.

Recommended Dose and Dosage Adjustment

Adults

For treatment of pain from irritated or inflamed mucous membranes of the mouth and throat, 5-10 mL of lidocaine viscous (100 - 200 mg lidocaine) is recommended. Six doses may be given in 24 hours. Total dosage of XYLOCAINE Viscous 2% in 24 hours should not exceed 60 mL or 1200 mg lidocaine.

For topical anesthesia before introduction of instruments and catheters into the upper respiratory or digestive tracts, 10 - 15 mL of lidocaine viscous (200 - 300 mg lidocaine) is recommended. When combined with other lidocaine products (e.g. for bronchoscopy), the total dosage of lidocaine should not exceed 400 mg.

For diseases of the upper gastrointestinal tract, 5 - 15 mL of lidocaine viscous (100 - 300 mg of lidocaine) should be swallowed quickly in one gulp. Six doses may be given in 24 hours. Total dosage of XYLOCAINE Viscous 2% in 24 hours should not exceed 60 mL or 1200 mg lidocaine.

Children (Under 12 Years)

In children under the age of 12, for treatment of irritated or inflamed mucous membranes of the mouth and throat, the dose should not exceed 4 mg/kg. It is recommended that excess lidocaine viscous solution is spat out. No more than four doses should be given during 24 hours.

For children over 12 years of age doses should be commensurate with weight and physical condition.

Children (Under 3 Years)

In children under the age of 3, the dose should be accurately measured and applied to the affected area with a cotton tip applicator. The same procedure is also recommended for older children having problems in expectorating. No more than four doses should be given during 24 hours.

At the present time there is not enough documentation to allow recommendations for a more prolonged use of viscous lidocaine in children under the age of 3.

Storage And Stability

Store at 15 - 30°C. Protect from freezing.

HOW SUPPLIED

Dosage Forms, Composition And Packaging

Dosage Forms

XYLOCAINE Viscous 2% (lidocaine hydrochloride) is a clear to almost clear slightly coloured viscous liquid with an odour of cherries.

XYLOCAINE Viscous 2% has a low surface tension which provides for an even film over the mucous membrane. Prolonged contact is possible due to its high viscosity.

Composition
lidocaine hydrochloride 20 mg/mL
methylparaben
propylparaben
cherry essence
saccharin sodium
sodium carboxymethylcellulose to adjust viscosity.
sodium hydroxide to adjust pH to 6.0 - 7.0.
purified water

Packaging

XYLOCAINE Viscous 2% is supplied in 100 mL plastic bottles.

This leaflet was prepared by: AstraZeneca Canada Inc. Mississauga, Ontario L4Y 1M4. Last revised: April 2, 2008. FDA revision date: 5/31/1996

Last updated on RxList: 5/8/2008

Adverse experiences following the administration of lidocaine are similar in nature to those observed with other amide local anesthetic agents. These adverse experiences are, in general, dose-related and may result from high plasma levels caused by overdosage or rapid absorption, or may result from a hypersensitivity, idiosyncrasy or diminished tolerance on the part of the patient.

Serious adverse experiences are generally systemic in nature. The following types are those most commonly reported:

Central Nervous System: CNS manifestations are excitatory and/or depressant and may be characterized by the following signs and symptoms of escalating severity: circumoral paresthesia, lightheadedness, apprehension, euphoria, confusion, dizziness, drowsiness, hyperacusis, tinnitus, blurred vision, vomiting, sensations of heat, cold or numbness, twitching, tremors, convulsions, unconsciousness, respiratory depression and arrest. The excitatory manifestations (e.g., twitching, tremors, convulsions) may be very brief or may not occur at all, in which case the first manifestation of toxicity may be drowsiness merging into unconsciousness and respiratory arrest.

Drowsiness following the administration of lidocaine is usually an early sign of a high lidocaine plasma level and may occur as a consequence of rapid absorption.

Cardiovascular System: Cardiovascular manifestations are usually depressant and are characterized by bradycardia, hypotension, arrhythmia and cardiovascular collapse, which may lead to cardiac arrest.

Allergic: Allergic reactions are characterized by cutaneous lesions, urticaria, edema or, in the most severe instances, anaphylactic shock. Allergic reactions of the amide type are rare ( < 0.1%) and may occur as a result of sensitivity either to the local anesthetic agent or to other components in the formulation (See DOSAGE FORM, COMPOSITION AND PACKAGING).

Overview

Lidocaine is mainly metabolized in the liver by CYP1A2 and CYP3A4 to its two major metabolites, monoethylglycinexylidine (MEGX) and glycinexylidine (GX), both of which are pharmacologically active. Lidocaine has a high hepatic extraction ratio. Only a small fraction (2%) of lidocaine is excreted unchanged in the urine. The hepatic clearance of lidocaine is expected to depend largely on blood flow.

Strong inhibitors of CYP1A2, such as fluvoxamine, given concomitantly with lidocaine, can cause a metabolic interaction leading to an increased lidocaine plasma concentration. Therefore, prolonged administration of lidocaine should be avoided in patients treated with strong inhibitors of CYP1A2, such as fluvoxamine. When co-administered with intravenous lidocaine, two strong inhibitors of CYP3A4, erythromycin and itraconazole, have each been shown to have a modest effect on the pharmacokinetics of intravenous lidocaine. Other drugs such as propranolol and cimetidine have been reported to reduce intravenous lidocaine clearance, probably through effects on hepatic blood flow and/or metabolism.

When lidocaine is used topically, plasma concentrations are of importance for safety reasons (see WARNINGS AND PRECAUTIONS, General; ADVERSE REACTIONS). However, with the low systemic exposure and short duration of topical application, the abovementioned metabolic drug-drug interactions are not expected to be of clinical significance when XYLOCAINE Viscous 2% is used according to dosage recommendations.

Clinically relevant pharmacodynamic drug interactions may occur with lidocaine and other local anesthetics or structurally related drugs, and Class I and Class III antiarrhythmic drugs due to additive effects.

Drug-Drug Interactions

Local anesthetics and agents structurally related to amide-type local anesthetics

Lidocaine should be used with caution in patients receiving other local anesthetics or agents structurally related to amide-type local anesthetics (e.g. antiarrhythmics such as mexiletine), since the toxic effects are additive.

Antiarryhythmic Drugs

Class I Antiarrhythmic drugs

Class I antiarrhythmic drugs (such as mexiletine) should be used with caution since toxic effects are additive and potentially synergistic.

Class III Antiarrhythmic drugs

Caution is advised when using Class III antiarrhythmic drugs concomitantly with lidocaine due to potential pharmacodynamic or pharmacokinetic interactions with lidocaine, or both. A drug interaction study has shown that the plasma concentration of lidocaine may be increased following administration of a therapeutic dose of intravenous lidocaine to patients treated with amiodarone (n=6). Case reports have described toxicity in patients treated concomitantly with lidocaine and amiodarone. Patients treated with Class III antiarrhythmic drugs (e.g. amiodarone) should be kept under close surveillance and ECG monitoring should be considered, since cardiac effects of these drugs and lidocaine may be additive.

Strong Inhibitors of CYP1A2 and CYP3A4

Cytochrome CYP1A2 and CYP3A4 are involved in the formation of the pharmacologically active lidocaine metabolite MEGX.

Fluvoxamine: Strong inhibitors of CYP1A2, such as fluvoxamine, given during prolonged administration of lidocaine to areas with a high extent of systemic absorption (e.g., mucous membranes) can cause a metabolic interaction leading to an increased lidocaine plasma concentration. The plasma clearance of a single intravenous dose of lidocaine was reduced by 41 to 60% during co-administration of fluvoxamine, a selective and potent CYP1A2 inhibitor, to healthy volunteers.

Erythromycin and Itraconazole: Erythromycin and itraconazole, which are strong inhibitors of CYP3A4, have been shown to reduce clearance of lidocaine by 9 to 18%, following a single intravenous dose of lidocaine to healthy volunteers.

During combined co-administration with fluvoxamine and erythromycin the plasma clearance of lidocaine was reduced by 53%.

β-blockers and cimetidine

Following a single intravenous dose of lidocaine, administered to healthy volunteers, the clearance of lidocaine has been reported to be reduced up to 47% when co-administered with propanolol and up to 30% when co-administered with cimetidine.Reduced clearance of lidocaine when co-administered with these drugs is probably due to reduced liver blood flow and/or inhibition of microsomal liver enzymes. The potential for clinically significant interactions with these drugs should be considered during long-term treatment with high doses of lidocaine.

Drug-Food Interactions

Interactions of lidocaine with food have not been established.

Drug-Herb Interactions

Interactions of lidocaine with herbal products have not been established.

Drug-Laboratory Tests Interactions

Interactions of lidocaine with laboratory tests have not been established.

Drug-Lifestyle Interactions

Interactions of lidocaine with lifestyle have not been established.

Last updated on RxList: 5/8/2008

Included as part of the PRECAUTIONS section.

General

EXCESSIVE DOSAGE, OR SHORT INTERVALS BETWEEN DOSES, CAN RESULT IN HIGH PLASMA LEVELS OF LIDOCAINE OR ITS METABOLITES AND SERIOUS ADVERSE EFFECTS. Following too high or repeated doses of viscous lidocaine in children under the age of three, serious side effects have been reported. Absorption from the wound surfaces and mucous membranes is variable but is especially high from the bronchial tree. Such applications may therefore result in rapidly rising or excessive plasma concentrations, with an increased risk for toxic symptoms, such as convulsions. PATIENTS SHOULD BE INSTRUCTED TO STRICTLY ADHERE TO THE RECOMMENDED DOSAGE. This is especially important in children where doses vary with weight. The management of serious adverse reactions may require the use of resuscitative equipment, oxygen and other resuscitative drugs (see OVERDOSAGE).

The lowest dosage that results in effective anesthesia should be used to avoid high plasma levels and serious adverse effects. Tolerance to elevated blood levels varies with the status of the patient.

XYLOCAINE VISCOUS 2% (lidocaine hydrochloride) IS FOR TOPICAL USE ONLY AND MUST NOT BE USED FOR INJECTION.

Lidocaine should be used with caution in patients with sepsis and/or traumatized mucosa at the area of application, since under such conditions there is the potential for rapid systemic absorption.

XYLOCAINE Viscous 2% should be used with caution in children under the age of 2 as there is insufficient data to support the safety and efficacy of this product in this patient population at this time.

In patients under general anesthesia who are paralyzed, higher plasma concentrations may occur than in spontaneously breathing patients. Unparalyzed patients are more likely to swallow a large proportion of the dose, which then undergoes considerable first-pass hepatic metabolism following absorption from the gut.

Avoid contact with eyes.

Many drugs used during the conduct of anesthesia are considered potential triggering agents for familial malignant hyperthermia. It has been shown that the use of amide local anesthetics in malignant hyperthermia patients is safe. However there is no guarantee that neural blockade will prevent the development of malignant hyperthermia during surgery. It is also difficult to predict the need for supplemental general anesthesia. Therefore a standard protocol for the management of malignant hyperthermia should be available.

When topical anesthetics are used in the mouth, the patient should be aware that the production of topical anesthesia may impair swallowing and thus enhance the danger of aspiration. Numbness of the tongue or buccal mucosa may enhance the danger of unintentional biting trauma. Food or chewing gum should not be taken while the mouth or throat area is anesthetized. See also Part III: Consumer Information.

XYLOCAINE Viscous 2% is ineffective when applied to intact skin.

Lidocaine has been shown to be porphyrinogenic in animal models. XYLOCAINE Topical 4% should only be prescribed to patients with acute porphyria on strong or urgent indications, when they can be closely monitored. Appropriate precautions should be taken for all porphyric patients.

Cardiovascular

Lidocaine should be used with caution in patients with bradycardia or impaired cardiovascular function since they may be less able to compensate for functional changes associated with the prolongation of A-V conduction produced by amide-type local anesthetics. Lidocaine should be used with caution in patients in severe shock.

Neurologic

Epilepsy: The risk of central nervous system side effects when using lidocaine in patients with epilepsy is very low, provided that the dose recommendations are followed (See DOSAGE AND ADMINISTRATION).

Locomotion and Coordination: Topical lidocaine formulations generally result in low plasma concentrations because of a low degree of systemic absorption. However, depending on the dose, local anesthetics may have a very mild effect on mental function and coordination even in the absence of overt CNS toxicity and may temporarily impair locomotion and alertness.

Renal

Lidocaine is metabolized primarily by the liver to monoethylglycinexylidine (MEGX, which has some CNS activity), and then further to metabolites glycinexylidine (GX) and 2,6-dimethylaniline (see ACTION AND CLINICAL PHARMACOLOGY). Only a small fraction (2%) of lidocaine is excreted unchanged in the urine. The pharmacokinetics of lidocaine and its main metabolite were not altered significantly in haemodialysis patients (n=4) who received an intravenous dose of lidocaine. Therefore, renal impairment is not expected to significantly affect the pharmacokinetics of lidocaine when XYLOCAINE Viscous 2% is used for short treatment durations, according to dosage instructions (see DOSAGE AND ADMINISTRATION). Caution is recommended when lidocaine is used in patients with severely impaired renal function because lidocaine metabolites may accumulate during long term treatment (see DOSAGE AND ADMINISTRATION). Hepatic

Because amide-type local anesthetics such as lidocaine are metabolized by the liver, these drugs, especially repeated doses, should be used cautiously in patients with hepatic disease. Patients with severe hepatic disease, because of their inability to metabolize local anesthetics normally, are at greater risk of developing toxic plasma concentrations.

Sensitivity

Lidocaine should be used with caution in persons with known drug sensitivities. XYLOCAINE Viscous 2% is contraindicated in patients with known hypersensitivities to local anesthetics of the amide type, to other components in the formulation, methylparaben and/or propylparaben (preservatives) and their metabolite para amino benzoic acid (PABA). The use of paraben-containing lidocaine preparations should also be avoided in patients who are allergic to ester local anesthetics (see CONTRAINDICATIONS).

Special Populations

Debilitated patients, acutely ill patients and patients with sepsis should be given reduced doses commensurate with their age, weight and physical condition because they may be more sensitive to systemic effects due to increased blood levels of lidocaine following repeated doses.

Pregnant Women: There are no adequate and well-controlled studies in pregnant women on the effect of lidocaine on the developing fetus.

It is reasonable to assume that a large number of pregnant women and women of child-bearing age have been given lidocaine. No specific disturbances to the reproductive process have so far been reported, e.g. no increased incidence of malformations. However, care should be given during early pregnancy when maximum organogenesis takes place.

Labour and Delivery: Should XYLOCAINE Viscous 2% be used concomitantly with other products containing lidocaine during labour and delivery, the total dose contributed by all formulations must be kept in mind.

Nursing Women: Lidocaine and its metabolites are excreted in the breast milk. At therapeutic doses the quantities of lidocaine and its metabolites in breast milk are small and generally are not expected to be a risk for the infant.

Pediatrics: Children should be given reduced doses commensurate with their age, weight and physical condition because they may be more sensitive to systemic effects due to increased blood levels of lidocaine following repeated doses (see DOSAGE AND ADMINISTRATION).

XYLOCAINE Viscous 2% should be used with caution in children under the age of 2 as there is insufficient data to support the safety and efficacy of this product in this patient population at this time.

Geriatrics: Elderly patients may be more sensitive to systemic effects due to increased blood levels of lidocaine following repeated doses and may require dose reductions.

Carcinogenesis and Mutagenesis

Genotoxicity tests with lidocaine showed no evidence of mutagenic potential. A metabolite of lidocaine, 2,6-dimethylaniline, showed weak evidence of activity in some genotoxicity tests. A chronic oral toxicity study of the metabolite 2,6-dimethylaniline (0, 14, 45, 135 mg/kg) administered in feed to rats showed that there was a significantly greater incidence of nasal cavity tumors in male and female animals that had daily oral exposure to the highest dose of 2,6-dimethylaniline for 2 years. The lowest tumor-inducing dose tested in animals (135 mg/kg) corresponds to approximately 50 times the amount of 2,6-dimethylaniline to which a 50 kg subject would be exposed following the application of 20 g of lidocaine viscous 2% for 24 hours on the mucosa, assuming the highest theoretical extent of absorption of 100% and 80% conversion to 2,6-dimethylaniline. Based on a yearly exposure (once daily dosing with 2,6-dimethylaniline in animals and 5 treatment sessions with 20 g lidocaine viscous 2% in humans), the safety margins would be approximately 3400 times when comparing the exposure in animals to man.

Last updated on RxList: 5/8/2008

Acute systemic toxicity from local anesthetics is generally related to high plasma levels encountered during therapeutic use of local anesthetics and originates mainly in the central nervous and the cardiovascular systems (see ADVERSE REACTIONS and WARNINGS AND PRECAUTIONS). It should be kept in mind that clinically relevant pharmacodynamic drug interactions (i.e., toxic effects) may occur with lidocaine and other local anesthetics or structurally related drugs, and Class I and Class III antiarrhythmic drugs due to additive effects (see DRUG INTERACTIONS).

Symptoms

Central nervous system toxicity is a graded response with symptoms and signs of escalating severity. The first symptoms are circumoral paresthesia, numbness of the tongue, lightheadedness, hyperacusis and tinnitus. Visual disturbance and muscular tremors are more serious and precede the onset of generalized convulsions. Unconsciousness and grand mal convulsions may follow, which may last from a few seconds to several minutes. Hypoxia and hypercarbia occur rapidly following convulsions due to the increased muscular activity, together with the interference with normal respiration. In severe cases apnea may occur. Acidosis, hyperkalaemia, hypocalcaemia and hypoxia increase and extend the toxic effects of local anesthetics.

Recovery is due to redistribution and metabolism of the local anesthetic drug. Recovery may be rapid unless large amounts of the drug have been administered.

Cardiovascular effects may be seen in cases with high systemic concentrations. Severe hypotension, bradycardia, arrhythmia and cardiovascular collapse may be the result in such cases.

Cardiovascular toxic effects are generally preceded by signs of toxicity in the central nervous system, unless the patient is receiving a general anesthetic or is heavily sedated with drugs such as a benzodiazepine or barbiturate.

Treatment

The first consideration is prevention, best accomplished by careful and constant monitoring of cardiovascular and respiratory vital signs and the patient's state of consciousness after each local anesthetic administration. At the first sign of change, oxygen should be administered.

The first step in the management of systemic toxic reactions consists of immediate attention to the maintenance of a patent airway and assisted or controlled ventilation with oxygen and a delivery system capable of permitting immediate positive airway pressure by mask. This may prevent convulsions if they have not already occurred.

If convulsions occur, the objective of the treatment is to maintain ventilation and oxygenation and support circulation. Oxygen must be given and ventilation assisted if necessary (mask and bag or tracheal intubation). Should convulsions not stop spontaneously after 15-20 seconds, an anticonvulsant should be given iv to facilitate adequate ventilation and oxygenation. Thiopental sodium 1-3 mg/kg iv is the first choice. Alternatively diazepam 0.1mg/kg bw iv may be used, although its action will be slow. Prolonged convulsions may jeopardise the patient's ventilation and oxygenation. If so, injection of a muscle relaxant (e.g. succinylcholine 1mg/kg bw) will facilitate ventilation, and oxygenation can be controlled. Early endotracheal intubation is required when succinylcholine is used to control motor seizure activity.

If cardiovascular depression is evident (hypotension, bradycardia), ephedrine 5 - 10 mg i.v. should be given and repeated, if necessary, after 2 - 3 minutes.

Should circulatory arrest occur, immediate cardiopulmonary resuscitation should be instituted. Optimal oxygenation and ventilation and circulatory support as well as treatment of acidosis are of vital importance, since hypoxia and acidosis will increase the systemic toxicity of local anesthetics. Epinephrine (0.1 - 0.2 mg as intravenous or intracardial injections) should be given as soon as possible and repeated, if necessary.

Children should be given doses of epinephrine commensurate with their age and weight.

XYLOCAINE Viscous 2% (lidocaine hydrochloride) is contraindicated in:

• patients with a known history of hypersensitivity to local anesthetics of the amide type or to other components of the solution (see DOSAGE FORMS, COMPOSITION AND PACKAGING).
• patients with a known hypersensitivity to methylparaben and/or propylparaben (preservatives used in XYLOCAINE Viscous 2%), or to their metabolite para amino benzoic acid (PABA).

Formulations of lidocaine containing parabens should also be avoided in patients with a history of allergic reactions to ester local anesthetics, which are metabolized to PABA.

Last updated on RxList: 5/8/2008

Mechanism of Action

Lidocaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby, effecting local anesthetic action. Local anesthetics of the amide type are thought to act within the sodium channels of the nerve membrane.

Onset of Action

After application of XYLOCAINE Viscous 2% (lidocaine hydrochloride), local anesthesia is achieved within 5 minutes. Duration of anesthesia is approximately 20 - 30 minutes. XYLOCAINE Viscous 2% is ineffective when applied to intact skin.

Hemodynamics

Lidocaine, like other local anesthetics, may also have effects on excitable membranes in the brain and myocardium. If excessive amounts of drug reach the systemic circulation rapidly, symptoms and signs of toxicity will appear, emanating from the central nervous and cardiovascular systems.

Central nervous system toxicity (see OVERDOSAGE) usually precedes the cardiovascular effects since it occurs at lower plasma concentrations. Direct effects of local anesthetics on the heart include slow conduction, negative inotropism and eventually cardiac arrest.

Pharmacokinetics

Absorption: The rate and extent of absorption depends upon concentration and total dose administered, the specific site of application and duration of exposure. In general, the rate of absorption of local anesthetic agents, following topical application to wound surfaces and mucous membranes is high, and occurs most rapidly after intratracheal and bronchial administration. Lidocaine is also well absorbed from the gastrointestinal tract, although little of the intact drug may appear in the circulation because of biotransformation in the liver.

Distribution: Lidocaine has a total plasma clearance of 0.95 L/min and a volume of distribution at steady state of 91 L.

Lidocaine readily crosses the placenta, and equilibrium in regard to free, unbound drug will be reached. Because the degree of plasma protein binding in the fetus is less than in the mother, the total plasma concentration will be greater in the mother, but the free concentrations will be the same.

The plasma binding of lidocaine is dependent on drug concentration, and the fraction bound decreases with increasing concentration. At concentrations of 1 to 4 µg of free base per mL, 60 to 80 percent of lidocaine is protein bound. Binding is also dependent on the plasma concentration of the alpha-1-acid glycoprotein.

Metabolism: Lidocaine is metabolized rapidly by the liver, and metabolites and unchanged drug are excreted by the kidneys. Biotransformation includes oxidative N-dealkylation, ring hydroxylation, cleavage of the amide linkage, and conjugation. Only 2% of lidocaine is excreted unchanged. Most of it is metabolized first to monoethylglycinexylidide (MEGX) and then to glycinexylidide (GX) and 2,6-dimethylaniline. Up to 70% appears in the urine as 4-hydroxy- 2,6-dimethylaniline.

Excretion: Lidocaine has an elimination half-life of 1.6 h and an estimated hepatic extraction ratio of 0.65. The clearance of lidocaine is almost entirely due to liver metabolism, and depends both on liver blood flow and the activity of metabolizing enzymes.

The elimination half-life of lidocaine following an intravenous bolus injection is typically 1.5 to 2.0 hours. The elimination half-life in neonates (3.2 h) is approximately twice that of adults. The half-life may be prolonged two-fold or more in patients with liver dysfunction. Renal dysfunction does not affect lidocaine kinetics but may increase the accumulation of metabolites.

Special Populations and Conditions

Acidosis increases the systemic toxicity of lidocaine while the use of CNS depressants may increase the levels of lidocaine required to produce overt CNS effects. Objective adverse manifestations become increasingly apparent with increasing venous plasma levels above 6.0mg free base per ml.

Last updated on RxList: 5/8/2008

XYLOCAINE® VISCOUS 2%
(lidocaine hydrochloride solution)

This leaflet is part III of a two-part “Prescribing Information” published when XYLOCAINE Viscous 2% was approved for sale in Canada and is designed specifically for Consumers. This leaflet is a summary and will not tell you everything about XYLOCAINE Viscous 2%. Contact your doctor or pharmacist if you have any questions about the drug.

Before using XYLOCAINE Viscous 2%, read this leaflet carefully.

Please keep this leaflet to refer to until you have used up all your XYLOCAINE Viscous 2%.

This medicine has been prescribed for you personally and you should not pass it on to others. It may harm them, even if their symptoms are the same as yours.

ABOUT THIS MEDICATION

WHAT THE MEDICATION IS USED FOR:

XYLOCAINE Viscous 2% is used to produce a temporary loss of feeling or numbness of the area where it is applied in adults and children 2 years of age and older, and can be used:

• before certain types of examinations done by your doctor.

XYLOCAINE Viscous 2%could also:

• relieve the pain and discomfort of a sore throat, such as after the tonsils are removed;
• provide relief in other painful diseases of the mouth, throat or esophagus;
• cause a loss of feeling in the throat area, before certain types of examinations are performed by your doctor.

WHAT IT DOES:

XYLOCAINE Viscous 2%is the brand name for a topical anesthetic that contains the drug lidocaine. Topical anesthetics are used to produce a temporary loss of feeling or numbness on the area where they are applied.

XYLOCAINE Viscous 2%should start to work within 5 minutes after you apply it. The effect usually lasts 20 to 30 minutes.

WHEN IT SHOULD NOT BE USED:

Do not use XYLOCAINE Viscous 2%if you:

• are allergic to lidocaine, any other “-caine” type anesthetics, or any of the non-medicinal ingredients in the product (see NONMEDICINAL INGREDIENTS below)
• are allergic to methylparaben and/or propylparaben (preservatives used in XYLOCAINE Viscous 2%) or PABA.

WHAT THE MEDICINAL INGREDIENT IS:

lidocaine hydrochloride 2%

NONMEDICINAL INGREDIENTS:

XYLOCAINE Viscous 2%also contains sodium carboxymethylcellulose, methylparaben, propylparaben, cherry essence, saccharin sodium, purified water and sodium hydroxide.

Tell your doctor if you think you may be sensitive to any of the above ingredients.

WHAT DOSAGE FORMS IT COMES IN:

XYLOCAINE Viscous 2%, 100 mL bottles.

BEFORE you use XYLOCAINE Viscous 2% tell your doctor or pharmacist:

• about all health problems you have now or have had in the past;
• about other medicines you take, including ones you can buy without a prescription;
• if you are taking other medicines such as drugs used to treat irregular heart activity (anti-arrhythmics);
• if you have ever had a bad, unusual or allergic reaction to XYLOCAINE Viscous 2%or any other medicines ending with “caine”;
• if you think you may be allergic or sensitive to any ingredients in XYLOCAINE Viscous 2%(see above);
• if there is an infection, skin rash, cut or wound at or near the area you want to apply XYLOCAINE Viscous 2%;
• if you have a skin condition that is severe or that covers a large area;
• if you have a severe heart, kidney or liver disease (see PROPER USE OF THIS MEDICATION);
• if you have epilepsy (there is very low risk if used as per PROPER USE OF THIS MEDICATION section);
• If you or someone in your family has been diagnosed with porphyria;
• if you are experiencing severe shock;
• if you are pregnant, plan to become pregnant or are breastfeeding.

INTERACTIONS WITH THIS MEDICATION

Tell your doctor or pharmacist about any other drugs you take, or have recently taken, including:

• drugs you can buy without a prescription;
• anti-arrhythmic drugs for heart problems (e.g. mexiletine, amiodarone) (see PROPER USE OF THIS MEDICATION);
• other anesthetics (see PROPER USE OF THIS MEDICATION);
• propranolol for heart problems or cimetidine for gastrointestinal problems, if you are going to use high doses of XYLOCAINE Viscous 2% for a long time;
• fluvoxamine, for depression, if you are going to use high doses of XYLOCAINE Viscous 2% for a long time.

Usage of such medicines at the same time as XYLOCAINE Viscous 2% may increase the risk of serious side effects.

PROPER USE OF THIS MEDICATION

This medication is for topical use only.

USUAL DOSE:

If this medicine is recommended by your doctor, be sure to follow the directions for use that have been given. If you are treating yourself, follow the directions below. Check with your doctor or pharmacist if you have any questions about your directions.

The following are general guidelines for the maximum amount of XYLOCAINE Viscous 2%that should be used without a doctor's advice. These guidelines apply only to otherwise healthy people. If you have a special skin condition or other condition that requires a doctor's supervision, ask your doctor about the maximum amount of XYLOCAINE Viscous 2%that you should use.

Do not use more XYLOCAINE Viscous 2%; or more often or for a longer period of time than either your doctor ordered or than these package directions recommend as this may cause unwanted side effects (see SERIOUS SIDE EFFECTS, HOW OFTEN THEY HAPPEN AND WHAT TO DO ABOUT THEM).

Shake the bottle well before using this medicine, so that you get an even dose each time you use it.

• Use the smallest amount needed to control your symptoms.
• When used in the mouth or throat try to increase the length of time XYLOCAINE Viscous 2%is in contact with the affected area. For example, if you are treating mouth sores, swish the liquid around in your mouth and then spit it out. For a sore throat, roll the liquid around at the back of your throat or gargle, and then swallow the liquid.
• Do not drink water or other liquids right after you use XYLOCAINE Viscous 2%, as this will decrease the amount of relief you get from the medicine.
• Avoid contact with your eyes.

Use only an accurate measuring device, such as a measured cup or a measured teaspoon to dose this medicine.

Conditions where dose adjustments may be required:

• elderly patients
• acutely ill patients
• patients with severe liver disease
• patients with severe kidney disease
• patients also treated with other anesthetics or certain antiarrhythmic drugs (such as amiodarone or mexiletine)

Dose for Adults

The usual effective dose for adults is 5 - 10 mL at a time. Do not use this amount more than six times in a 24-hour period.

The total dose for a 24-hour period should be no more than 60 mL.

Dose for Children 2-12 Years of Age

The dose depends on the child's weight. No more than 1 mL per 5 kilogram of the child's weight should be used per dose. Excess solution should be spat out. No more than four doses should be given during a 24-hour period.

Dose for Children Under 3 Years of Age

There may be special considerations for children under 3 years of age. DO NOT use XYLOCAINE Viscous 2%for children in this age group without a doctor's supervision. The solution should be applied to the affected area with a cotton tip applicator. No more than four doses should be given during a 24-hour period.

• For use in children under 2 years of age, consult a doctor.
• If you have any questions about how to measure the above amounts, be sure to ask your pharmacist.
• If you are treating yourself and your condition does not seem to improve within three to five days, check with your doctor about continuing to use XYLOCAINE Viscous 2%.

OVERDOSE:

Early signs of overdosage are numbness of the lips and around the mouth, lightheadedness, dizziness and sometimes blurred vision. In the event of a serious overdosage, trembling, seizures or unconsciousness may occur.

If the early signs of overdosage are noticed and no further XYLOCAINE Viscous 2% is given, the risk of serious side effects occurring rapidly decreases. If you think you or anyone else is experiencing any of the above signs, telephone your doctor or go to the nearest hospital right away.

SIDE EFFECTS AND WHAT TO DO ABOUT THEM

Like any medication, XYLOCAINE Viscous 2%may cause side effects in some people.

Avoid eating or chewing gum when XYLOCAINE Viscous 2%is used in the mouth or throat since numbness in these areas may interfere with swallowing and could potentially cause choking. Numbness of the tongue or gum may also increase the danger of injury due to biting.

Avoid exposure to extreme hot or cold temperatures (e.g. food, drink) until complete sensation has returned.

Avoid contact with the eyes because numbness in the eyes may prevent you from noticing if you get something in your eye.

With the recommended doses, XYLOCAINE Viscous 2%has no effect on the ability to drive and use machines.

Medicines affect different people in different ways. Just because side effects have occurred in some patients, does not mean that you will get them. If any side effects bother you, or if you experience any unusual effects while you are using XYLOCAINE Viscous 2%, stop using it and check with your doctor or pharmacist as soon as possible.

SERIOUS SIDE EFFECTS, HOW OFTEN THEY HAPPEN AND WHAT TO DO ABOUT THEM

This is not a complete list of side effects. For any unexpected effects while taking XYLOCAINE Viscous 2% contact your doctor or pharmacist.

XYLOCAINE Viscous 2%can cause serious side effects if too much is used. These include: drowsiness, numbness of your tongue, light-headedness, ringing in your ears, blurred vision, vomiting, dizziness, unusually slow heart beat, fainting, nervousness, unusual sweating, trembling or seizures.

The above are extremely rare and usually require large amounts of XYLOCAINE Viscous 2%over a long period of time.

Consult your doctor immediately if any of these symptoms appear.

HOW TO STORE IT

Remember to keep XYLOCAINE Viscous 2% well out of the reach of children when you are not using it.

Keep XYLOCAINE Viscous 2%at room temperature. Protect from freezing. Do not keep XYLOCAINE Viscous 2%in the bathroom medicine cabinet or other warm, moist places. Store in the original package.

Do not use XYLOCAINE Viscous 2%after the expiry date marked on the package.

MORE INFORMATION

Important Note: This leaflet alerts you to some of the times you should call your doctor. Other situations which cannot be predicted may arise. Nothing about this leaflet should stop you from calling your doctor with any questions or concerns you have about using XYLOCAINE Viscous 2%.

NOTE: This CONSUMER INFORMATION leaflet provides you with the most current information at the time of printing.

For the most current information, the Consumer Information Leaflet plus the full Prescribing Information, prepared for health professionals can be found at: www.astrazeneca.ca or by contacting the sponsor, AstraZeneca Canada Inc. at: Customer Inquiries - 1 (800) 668-6000, Renseignements - 1 (800) 461-3787.

Last updated on RxList: 5/8/2008

IMPORTANT NOTE: This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your health care professional. Always seek the advice of your health care professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your health care professional. This information does not contain any assurances that this product is safe, effective, or appropriate for you.

LIDOCAINE VISCOUS

(LIE-doh-cane)

COMMON BRAND NAME(S): Xylocaine Viscous

USES: Viscous lidocaine is used to relieve pain and discomfort from a sore throat/mouth. It is also used to numb the lining of the mouth and throat before certain medical/dental procedures (e.g., dental impressions). This numbing helps prevent the urge to close the throat (gag reflex), which might make the procedure more difficult. Lidocaine is an amide-type local anesthetic that starts to numb the area minutes after application.

HOW TO USE: Shake the bottle well before measuring each dose carefully. Use a special measuring spoon or device to measure your dose. Do not use a household spoon since you may get an incorrect dose.

Do not mix with other liquid or food unless directed by your doctor. For mouth pain, swish the prescribed amount in your mouth and spit out. Do not swallow the medication. Viscous lidocaine is usually used as needed when you have pain or soreness, but do not use it more often than every 3 hours or as directed by your doctor. The usual maximum dose for an adult is 15 milliliters for each dose and no more than 8 doses in 24 hours.

Dosage is based on your medical condition and response to therapy. Be very careful to measure the dose carefully, especially if you are using this medication in a child. Accidental overdose has occurred in children when the dose was not correct. Dosage in children may also be based on age and weight and is less than the adult dose.

For infants and children younger than 3 years, carefully measure the prescribed dose and apply to the area to be treated with a cotton swab.

To treat a sore throat, gargle with the medication, then swallow it to numb the throat, or spit out, as directed by your doctor.

This medication numbs the nose and throat. This will make swallowing difficult and increase your risk of choking or swallowing the wrong way. Do not eat or chew gum for 1 hour after using this product or until your mouth/throat is no longer numb. It is especially important to make sure children do not eat or chew gum for at least 1 hour after use. Be careful not to accidentally bite your tongue or mouth.

Follow your doctor's instructions carefully, and do not increase your dose or use this more often than prescribed without your doctor's approval. Using too much product or using it too often can increase the risk of very serious side effects.

Tell your doctor if your condition persists or worsens.

SIDE EFFECTS: Mild nausea, stinging, and burning may occur. Dizziness and drowsiness may also occur. If these effects persist or worsen, notify your doctor promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these rare but very serious side effects occur: slow/shallow breathing, slow/irregular heartbeat, mental/mood changes (e.g., severe drowsiness, confusion, nervousness), seizures, vision changes (e.g., double or blurred vision).

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction: rash, itching, swelling, severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Contact your doctor for medical advice about side effects. The following numbers do not provide medical advice, but in the US you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088. In Canada, you may call Health Canada at 1-866-234-2345.

PRECAUTIONS: Before using lidocaine, tell your doctor, dentist, or pharmacist if you are allergic to it; or to other anesthetics (e.g., bupivacaine, prilocaine); or to PABA; or if you have any other allergies.

Before using this medication, tell your dentist, doctor, or pharmacist your medical history, especially of: bites/cuts/scrapes/sores in your mouth or throat, heart problems (e.g., slow/irregular heartbeat), severe infection with high fever (e.g., sepsis), liver disease.

To minimize dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

This drug may make you dizzy or drowsy. Use caution while driving, using machinery, or doing any activity that requires alertness. Limit alcoholic beverages.

Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug, especially the effects on the heart.

Caution is advised when using this drug in children because they may be more sensitive to the effects of the drug, especially dizziness and drowsiness.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is not known if this medication passes into breast milk. Consult your doctor before breastfeeding.

DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

Before using this medication, tell your dentist, doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: class I antiarrhythmic drugs (e.g., disopyramide, procainamide, quinidine), pimozide.

Other drugs besides lidocaine and those listed above that may affect the heart rhythm (QTc prolongation in the EKG) include amiodarone, dofetilide, sotalol, and erythromycin, among others. QTc prolongation can infrequently result in a serious (rarely fatal) irregular heartbeat. Consult your doctor or pharmacist for more details and for instructions on how you may minimize this risk of this effect.

Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-seizure drugs (e.g., carbamazepine), medicine for sleep or anxiety (e.g., alprazolam, diazepam, zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., chlorpromazine, risperidone, amitriptyline, trazodone).

Check the labels on all your medicines (e.g., cough-and-cold products) because they may contain drowsiness-causing ingredients. Ask your pharmacist about using those products safely.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If overdose is suspected, contact your local poison control center or emergency room immediately. US residents should call the US National Poison Hotline at 1-800-222-1222. Canada residents should call a provincial poison control center. Symptoms of overdose may include: severe dizziness/drowsiness, seizures, slow/irregular heartbeat.

NOTES: Do not share this medication with others.

This medication has been prescribed for your current condition only. Do not use it later for another condition unless told to do so by your doctor. A different medication may be necessary in that case.

MISSED DOSE: Not applicable.

STORAGE: Store at room temperature away from sunlight and moisture. Do not freeze. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised July 2008 Copyright(c) 2008 First DataBank, Inc.