Astracaine (Articaine HCl – Epinephrine)



Articaine HCl – Epinephrine

Local Anesthetic

Action And Clinical Pharmacology: Articaine is a local anesthetic of the amide type. As with other local anesthetics, it prevents the generation and conduction of the nerve impulse by interfering with the large transient increase in the permeability of the membrane to sodium ions.

Epinephrine acts on alpha-adrenergic receptors in the vasculature of the mucous membranes to produce vasoconstriction, thereby decreasing blood flow in the area of injection. This results in a reduction in the rate of local clearance of articaine which prolongs its duration of action, lowers the peak serum concentration, decreases the risk of systemic toxicity and increases the frequency of complete conduction blocks with low concentrations of the local anesthetic.

Following intraoral injection of a 240 mg dose of articaine 4% with epinephrine 5 µg/mL in healthy volunteers, peak plasma levels (Cmax) of 1.17±0.14 µg/mL were reached at approximately 17 minutes. The elimination half-life (T1/2) was 25.28±3.3 minutes.

Articaine is excreted mainly by the kidneys. Of an epidural dose, approximately 2 to 5% is excreted unchanged, 40 to 70% is excreted as articainic acid and 4 to 15% as articainic acid glucuronide.

When used for infiltration or nerve block anesthesia, the onset of action for articaine hydrochloride with epinephrine is 1 to 2 minutes.

The duration of anesthesia varies depending on the type of block and the amount injected.

Indications And Clinical Uses: For infiltration anesthesia and nerve block anesthesia in clinical dentistry.

Contra-Indications: Patients with a known hypersensitivity to local anesthetics of the amide type. As with all vasoconstrictors, epinephrine is contraindicated in hypertension, thyrotoxicosis, or severe heart disease, particularly when tachycardia is present. Local anesthetics should not be used in severe shock or heart block. They should also not be used when there is inflammation or sepsis in the region of the proposed injection.

Manufacturers’ Warnings In Clinical States: Resuscitative equipment and drugs should be immediately available when any local anesthetic is used.

As with other local anesthetics, articaine is capable of producing methemoglobinemia. This has been observed with epidural anesthesia, but not when used as directed in dental procedures.

Methemoglobinemia values of less than 20% usually do not produce any clinical symptoms. The usual clinical signs of methemoglobinemia are cyanosis of the nail beds and lips. Although the possibility of methemoglobinemia occurring in dental patients is extremely rare it can be rapidly reversed by the use of 1 to 2 mg/kg body weight of methylene blue administered i.v. over a 5-minute period.

Because Astracaine contains a vasoconstrictor, it should be used with extreme caution in patients receiving drugs known to produce blood pressure alterations (for example MAO inhibitors, tricyclic antidepressants, phenothiazines), as either severe and sustained hypotension or hypertension may occur.

Precautions: General: The safety and effectiveness of local anesthetics depend upon proper dosage, correct technique, adequate precautions and readiness for emergencies.

The lowest dose that results in effective anesthesia should be used to avoid high plasma levels and serious undesirable adverse effects. Injections should be made slowly, with frequent aspirations before and during the injection. If blood is aspirated, the needle should be relocated. Tolerance varies with the status of the patient. Debilitated or elderly patients, acutely ill patients and children should be given reduced doses commensurate with their age and physical status.

Pregnancy : Safe use of articaine in pregnant women has not been established; however, animal studies have not demonstrated teratogenic or embryotoxic effects.

Lactation : Articaine is rapidly metabolized and eliminated and is therefore unlikely to be transferred to the mother’s milk.

Patients with Special Diseases and Conditions: Astracaine contains a vasoconstrictor and should therefore be used with caution in the presence of diseases which may adversely affect the patient’s cardiovascular system.

The drug should be used with caution in persons with known drug sensitivities. Astracaine contains sodium metabisulfite. Sulfates may cause allergic reactions in susceptible people. The prevalence of sulfite sensitivity in the general population is unknown and probably low, but it is seen more frequently in patients with bronchial asthma. Reactions can include anaphylactic symptoms and life-threatening or less severe asthmatic episodes.

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.

Drug Interactions: Serious cardiac arrhythmias may occur if preparations containing a vasoconstrictor are employed in patients during or following the administration of chloroform, halothane, cycloproprane, trichloroethylene or other related agents.

Caution should be exercised when administering articaine concomitantly with other medications which are potential producers of methemoglobin (e.g., sulfonamides).

Adverse Reactions: Reactions to articaine are characteristic of those associated with amide-type local anesthetics.

Adverse reactions may result from high plasma levels due to excessive dosage, rapid absorption or inadvertent intravascular injection, or may result from a hypersensitivity, idiosyncrasy or diminished tolerance on the part of the patient. Such reactions are systemic in nature and involve the CNS and/or the cardiovascular system.

CNS: CNS manifestations are excitatory and/or depressant and may be characterized by nervousness, dizziness, blurred vision and tremors, followed by drowsiness, convulsions, unconsciousness and possibly respiratory arrest. The excitatory reactions may be very brief or may not occur at all, in which case, the first manifestations of toxicity may be drowsiness, merging into unconsciousness and respiratory arrest.

Cardiovascular: Cardiovascular reactions are depressant and may be characterized by hypotension, myocardial depression, bradycardia and possibly cardiac arrest.

Allergic: Allergic reactions are characterized by cutaneous lesions, urticaria, edema or anaphylactoid reactions. The detection of sensitivity by skin testing is of doubtful value.

Swelling and persistent paresthesia of the lips and oral tissues have been reported after blocking the inferior alveolar nerve.

Symptoms And Treatment Of Overdose: Symptoms and Treatment: Treatment of a patient with toxic manifestations consists of assuring and maintaining a patent airway and supporting ventilation using oxygen and assisted or controlled respiration as required. This will be sufficient in the management of most reactions. Should circulatory depression occur, vasopressors, such as ephedrine or metaraminol, and i.v. fluids may be used. Should a convulsion persist despite oxygen therapy, small increments of an ultra-short acting barbiturate (thiopental or thiamylal) or a short-acting barbiturate (pentobarbital or secobarbital) may be given i.v.

Dosage And Administration: As with all local anesthetics, the dosage varies and depends on the area to be anesthetized, the vascularity of the tissues, the number of neuronal segments to be blocked, individual tolerance and the technique of anesthesia. The lowest dosage needed to provide effective anesthesia should be administered.

Adults: It is recommended that the dosage should not exceed 7 mg/kg body weight in adults and, in general, the maximum total dose should not exceed 500 mg (12.5 mL or 7 cartridges).

Children: Dosages in children should be reduced commensurate with their age and weight. Experience in children younger than 4 years of age has not been documented. The dosage should not exceed 5 mg/kg body weight in children between the ages of 4 and 12.

Availability And Storage: Astracaine 4%: Each mL of solution contains: articaine HCl 40 mg and epinephrine 5 µg (1:200 000). Nonmedicinal ingredients: sodium chloride, sodium hydroxide and/or hydrochloric acid to adjust pH range to 2.7 to 4.5, sodium metabisulfite and water for injection. Dental cartridges of 1.8 mL, boxes of 50.

Astracaine 4% Forte: Each mL of solution contains: articaine HCl 40 mg and epinephrine 10 µg (1:100 000). Nonmedicinal ingredients: sodium chloride, sodium hydroxide and/or hydrochloric acid to adjust pH range to 2.7 to 4.5, sodium metabisulfite and water for injection. Dental cartridges of 1.8 mL, boxes of 50.

Store at controlled room temperature (15 to 30°C). Protect from light. Do not use if solution is pinkish or darker than slightly yellow or if it contains a precipitate. Solutions are without preservative and are for single use only. Discard unused portion.

ASTRACAINE® ASTRACAINE® FORTE Astra Articaine HCl – Epinephrine Local Anesthetic

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