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Generic name: prilocaine systemic

Brand names: Citanest HCl Plain

Dosage Forms

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

Solution, Injection, as hydrochloride:

Citanest Plain Dental: 4% (1.8 mL)


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.



190 to 260 L; crosses blood-brain barrier


Primarily metabolized hepatically and to a lesser extent renally; prilocaine hydrolyzed by amidases to produce ortho-toluidine and N-propylalanine; these compounds may also undergo ring hydroxylation


Urine (<5% as unchanged drug)

Onset of Action

Infiltration: <2 minutes; Inferior alveolar nerve block: <3 minutes

Duration of Action

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

Half-Life Elimination

1.6 hours; may be prolonged with hepatic or renal impairment

Protein Binding

40% to 55% (alpha1 acid glycoprotein)

Use: Labeled Indications

Local anesthesia: Production of local anesthesia in dentistry by nerve block or infiltration techniques.


Hypersensitivity to local anesthetics of the amide type or any component of the formulation; patients with congenital or idiopathic methemoglobinemia

Canadian labeling: Additional contraindications (not in US labeling): Citanest Plain Dental: Severe shock or heart block; inflammation or sepsis in the region of proposed injection

Dosage and Administration

Dosing: Adult

Dental anesthesia: Infiltration or conduction block: Initial: 40 to 80 mg (1 to 2 mL) as a 4% solution. AAPD guidelines, 2009 maximum recommended dose within a 2-hour period:

<70 kg: 6 mg/kg (400 mg)

≥70 kg: 400 mg or 5 to 6 cartridges

Note: 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.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Dental anesthesia: Infiltration or conduction block:

Children <10 years: Doses >40 mg (1 mL) as a 4% solution per procedure rarely needed for procedures involving a single tooth, in a maxillary infiltration for 2 to 3 teeth, or for an entire quadrant with a mandibular block.

Children ≥10 years and Adolescents: Refer to adult dosing.


Store at 25°C (77°F). Do not freeze.

Drug Interactions

Bupivacaine (Liposomal): Local Anesthetics may enhance the adverse/toxic effect of Bupivacaine (Liposomal). Management: Liposomal bupivacaine should not be administered with local anesthetics. Liposomal bupivacaine may be administered 20 minutes or more after the administration of lidocaine, but the optimal duration of dose separation for other local anesthetics is unknown Avoid combination

Dapsone (Topical): May enhance the adverse/toxic effect of Methemoglobinemia Associated Agents. Monitor therapy

Hyaluronidase: May enhance the adverse/toxic effect of Local Anesthetics. Monitor therapy

Local Anesthetics: Methemoglobinemia Associated Agents may enhance the adverse/toxic effect of Local Anesthetics. Specifically, the risk for methemoglobinemia may be increased. Monitor therapy

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. Monitor therapy

Neuromuscular-Blocking Agents: Local Anesthetics may enhance the neuromuscular-blocking effect of Neuromuscular-Blocking Agents. Monitor therapy

Nitric Oxide: May enhance the adverse/toxic effect of Methemoglobinemia Associated Agents. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Monitor therapy

Sodium Nitrite: Methemoglobinemia Associated Agents may enhance the adverse/toxic effect of Sodium Nitrite. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Monitor therapy

Technetium Tc 99m Tilmanocept: Local Anesthetics may diminish the diagnostic effect of Technetium Tc 99m Tilmanocept. Management: Avoid mixing and simultaneously co-injecting technetium Tc 99m tilmanocept with local anesthetics. This interaction does not appear to apply to other uses of these agents in combination. Monitor therapy

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.

Frequency not defined.

Cardiovascular: Bradycardia, cardiac arrest, cardiovascular signs and symptoms (stimulation/depression), circulatory shock, edema, hypotension

Central nervous system: Apprehension, confusion, convulsions, dizziness, drowsiness, euphoria, localized warm feeling, loss of consciousness, nervousness, numbness, oral paresthesia (may be persistent), sensation of cold, twitching

Dermatologic: Dermal ulcer, urticaria

Gastrointestinal: Vomiting

Hematologic & oncologic: Methemoglobinemia

Hypersensitivity: Anaphylactoid reaction, hypersensitivity reaction

Neuromuscular & skeletal: Tremor

Ophthalmic: Blurred vision, diplopia

Otic: Tinnitus

Respiratory: Respiratory arrest, respiratory depression


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 local anesthetics; clinically significant methemoglobinemia requires immediate treatment along with discontinuation of the anesthetic and other oxidizing agents. Onset may be immediate or delayed (hours) after anesthetic exposure. Patients with glucose-6-phosphate dehydrogenase deficiency, congenital or idiopathic methemoglobinemia, cardiac or pulmonary compromise, exposure to oxidizing agents or their metabolites, or infants <6 months of age are more susceptible and should be closely monitored for signs and symptoms of methemoglobinemia (eg, cyanosis, headache, rapid pulse, shortness of breath, lightheadedness, fatigue). Use is contraindicated in patients with congenital or idiopathic methemoglobinemia.
  • 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, severe shock, or heart block.
  • Familial malignant hyperthermia: Prilocaine may potentially trigger malignant hyperthermia; follow standard protocol for identification and treatment.
  • Hepatic impairment: Use with caution in patients with hepatic impairment; amide-type anesthetics are metabolized hepatically.

Concurrent drug therapy issues:

  • Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

  • Acutely ill patients: Use with caution in acutely-ill patients; 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.
  • Pediatric: 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.
  • Appropriate dosing: To avoid serious adverse effects and high plasma concentrations, the lowest dosage resulting in effective anesthesia should be administered. Repeated doses may significantly increase blood concentrations of both the drug or its metabolites; tolerance to elevated blood concentrations varies with patient status. Reduced dosages, commensurate with age and physical condition, should be given to patients who are debilitated, elderly, acutely-ill, or pediatric.
  • 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.


Pregnancy Risk Factor


Pregnancy Considerations

Adverse events have not been observed in animal reproduction studies. Prilocaine crosses the placenta.

Patient Education

  • Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
  • Have patient report immediately to prescriber signs of methemoglobinemia (blue or gray color of the lips, nails, or skin; abnormal heartbeat; seizures; severe dizziness or passing out; severe headache; fatigue; loss of strength and energy; or shortness of breath), signs of acidosis (confusion, fast breathing, fast heartbeat, abnormal heartbeat, severe abdominal pain, nausea, vomiting, fatigue, shortness of breath, or loss of strength and energy), burning or numbness feeling, numbness or tingling around the mouth, dizziness, passing out, lightheadedness, fatigue, confusion, blurred vision, slow heartbeat, sweating a lot, change in balance, noise or ringing in the ears, depression, severe anxiety, difficulty breathing, slow breathing, shallow breathing, seizures, tremors, twitching, agitation, or sensations of warmth or cold (HCAHPS).
  • Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Source: Wolters Kluwer Health. Last updated January 15, 2020.