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Pronunciation

(PRIL oh kane)

Generic Available (U.S.)

No

Brand Names: U.S.

• Citanest® Plain Dental

Brand Names: Canada

• Citanest® Plain

Pharmacologic Category

• Local Anesthetic

Pharmacologic Category Synonyms

• Anesthetic, Local

Use: Dental

Amide-type anesthetic used for local infiltration anesthesia; injection near nerve trunks to produce nerve block

Pregnancy Risk Factor

B

Breast-Feeding Considerations

Usual infiltration doses of prilocaine given to nursing mothers has not been shown to affect the health of the nursing infant.

Contraindications

Hypersensitivity to local anesthetics of the amide type or any component of the formulation

Warnings/Precautions

Concerns related to adverse effects:

• CNS toxicity: Careful and constant monitoring of the patient's state of consciousness should be done following each local anesthetic injection; at such times, restlessness, anxiety, tinnitus, dizziness, blurred vision, tremors, depression, or drowsiness may be early warning signs of CNS toxicity. Treatment is primarily symptomatic and supportive.

• Methemoglobinemia: Has been reported with prilocaine.

• Respiratory arrest: Local anesthetics have been associated with rare occurrences of sudden respiratory arrest.

• Seizures: Convulsions due to systemic toxicity leading to cardiac arrest have also been reported, presumably following unintentional intravascular injection.

Disease-related concerns:

• Cardiovascular disease: Use with caution in patients with cardiovascular disease.

• Hepatic impairment: Use with caution in patients with hepatic impairment.

Special populations:

• Acutely ill patients: Use with caution in acutely ill; reduce dose consistent with age and physical status.

• Debilitated patients: Use with caution in debilitated patients; reduce dose consistent with age and physical status.

• Elderly: Use with caution in the elderly; reduce dose consistent with age and physical status.

• Pediatrics: Use with caution in children; reduce dose consistent with age and physical status.

Other warnings/precautions:

• Administration: Intravascular injections should be avoided; aspiration should be performed prior to administration; the needle must be repositioned until no return of blood can be elicited by aspiration; however, absence of blood in the syringe does not guarantee that intravascular injection has been avoided.

• Trained personnel: Dental practitioners using local anesthetic agents should be well trained in diagnosis and management of emergencies that may arise from the use of these agents. Resuscitative equipment, oxygen, and other resuscitative drugs should be available for immediate use.

Adverse Reactions

Degree of adverse effects in the central nervous system and cardiovascular system are directly related to the blood levels of local anesthetic. The effects below are more likely to occur after systemic administration rather than infiltration.

Cardiovascular: Myocardial effects include a decrease in contraction force as well as a decrease in electrical excitability and myocardial conduction rate resulting in bradycardia and reduction in cardiac output.

Central nervous system: High blood levels result in anxiety, restlessness, disorientation, confusion, dizziness, tremor, and seizure. This is followed by depression of CNS resulting in somnolence, unconsciousness and possible respiratory arrest. Nausea and vomiting may also occur. In some cases, symptoms of CNS stimulation may be absent and the primary CNS effects are somnolence and unconsciousness.

Hypersensitivity reactions: May be manifest as dermatologic reactions and edema at injection site. Asthmatic syndromes have occurred.

Psychogenic reactions: It is common to misinterpret psychogenic responses to local anesthetic injection as an allergic reaction. Intraoral injections are perceived by many patients as a stressful procedure in dentistry. Common symptoms to this stress are diaphoresis, palpitation, hyperventilation, generalized pallor and a fainting feeling

Metabolism/Transport Effects

None known.

Drug Interactions

Methemoglobinemia Associated Agents: May enhance the adverse/toxic effect of Prilocaine. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Management: Monitor patients for signs of methemoglobinemia (e.g., hypoxia, cyanosis) when prilocaine is used in combination with other agents associated with development of methemoglobinemia. Avoid lidocaine/prilocaine in infants receiving such agents. Risk C: Monitor therapy

Mechanism of Action

Local anesthetics bind selectively to the intracellular surface of sodium channels to block influx of sodium into the axon. As a result, depolarization necessary for action potential propagation and subsequent nerve function is prevented. The block at the sodium channel is reversible. When drug diffuses away from the axon, sodium channel function is restored and nerve propagation returns.

Pharmacodynamics/Kinetics

Onset of action: Infiltration: ~2 minutes; Inferior alveolar nerve block: ~3 minutes

Duration: Infiltration: Complete anesthesia for procedures lasting 20 minutes; Inferior alveolar nerve block: ~2.5 hours

Distribution: V_d: 0.7-4.4 L/kg; crosses blood-brain barrier

Protein binding: 55%

Metabolism: Hepatic and renal

Half-life elimination: 10-150 minutes; prolonged with hepatic or renal impairment

Dosage

Children <10 years: Doses >40 mg (1 mL) as a 4% solution per procedure rarely needed

Children >10 years and Adults: Dental anesthesia, infiltration, or conduction block: Initial: 40-80 mg (1-2 mL) as a 4% solution; up to a maximum of 400 mg (10 mL) as a 4% solution within a 2-hour period. Manufacturer's maximum recommended dose is not more than 600 mg to normal healthy adults. The effective anesthetic dose varies with procedure, intensity of anesthesia needed, duration of anesthesia required and physical condition of the patient. Always use the lowest effective dose along with careful aspiration.

Note: Adult and children doses of prilocaine hydrochloride cited from USP Dispensing Information (USP DI), 17th ed, The United States Pharmacopeial Convention, Inc, Rockville, MD, 1997, 139.

Dental Usual Dosing

Children <10 years: Doses >40 mg (1 mL) as a 4% solution per procedure rarely needed

Children >10 years and Adults: Dental anesthesia, infiltration, or conduction block: Initial: 40-80 mg (1-2 mL) as a 4% solution; up to a maximum of 400 mg (10 mL) as a 4% solution within a 2-hour period. Manufacturer's maximum recommended dose is not more than 600 mg to normal healthy adults. The effective anesthetic dose varies with procedure, intensity of anesthesia needed, duration of anesthesia required and physical condition of the patient. Always use the lowest effective dose along with careful aspiration.

The following numbers of dental carpules (1.8 mL) provide the indicated amounts of prilocaine hydrochloride 4%. See table.

Note: Adult and children doses of prilocaine hydrochloride cited from USP Dispensing Information (USP DI), 17th ed, The United States Pharmacopeial Convention, Inc, Rockville, MD, 1997, 139.

Anesthesia and Critical Care Concerns/Other Considerations

Addition of sodium bicarbonate to local anesthetic solution can increase onset and potency. Only preservative-free solutions should be used for epidural administration. The metabolite o-toluidine can cause methemoglobinemia when large doses of prilocaine >600 mg are administered.

Dental Health: Effects on Dental Treatment

It is common to misinterpret psychogenic responses to local anesthetic injection as an allergic reaction. Intraoral injections are perceived by many patients as a stressful procedure in dentistry. Common symptoms to this stress are diaphoresis, palpitations, hyperventilation, generalized pallor and a fainting feeling.

Degree of adverse effects in the CNS and cardiovascular system is directly related to blood levels of prilocaine (frequency not defined; more likely to occur after systemic administration rather than infiltration): Bradycardia and reduction in cardiac output, hypersensitivity reactions (may be manifest as dermatologic reactions and edema at injection site), asthmatic syndromes

High blood levels: Anxiety, restlessness, disorientation, confusion, dizziness, tremors, and seizures, followed by CNS depression, resulting in somnolence, unconsciousness and possible respiratory arrest; nausea and vomiting

In some cases, symptoms of CNS stimulation may be absent and the primary CNS effects are somnolence and unconsciousness.

Dental Health: Vasoconstrictor/Local Anesthetic Precautions

No information available to require special precautions

Mental Health: Effects on Mental Status

High blood levels result in anxiety, confusion, restlessness, disorientation, and dizziness. This is followed by CNS depression, resulting in somnolence, unconsciousness, and possible respiratory arrest. Symptoms of CNS stimulation may be absent and the primary CNS effects are somnolence and unconsciousness.

Mental Health: Effects on Psychiatric Treatment

None reported

Mental Health: Comment

It is common to misinterpret psychogenic responses to local anesthetic injection as an allergic reaction.

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Injection, solution, as hydrochloride [for dental use]:

Citanest® Plain Dental: 4% [40 mg/mL] (1.8 mL)

References

Jastak JT and Yagiela JA, “Vasoconstrictors and Local Anesthesia: A Review and Rationale for Use,” J Am Dent Assoc, 1983, 107(4):623-30.

MacKenzie TA and Young ER, “Local Anesthetic Update,” Anesth Prog, 1993, 40(2):29-34.

Wynn RL, “Epinephrine Interactions With Beta-Blockers,” Gen Dent, 1994, 42(1):16, 18.

Yagiela JA, “Local Anesthetics,” Anesth Prog, 1991, 38(4-5):128-41.

International Brand Names

• Citanest (BE, ES, FI, GB, LU, NL, NO, NZ, SE)
• Citanest Dental (AU)
• Xylonest (CH, DE)

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Last full review/revision January 2012

Content last modified January 2012