Prilocaine (Citanest) is a local anesthetic drug that is used in dental procedures as local infiltration into the skin or as a nerve block. It is also available in combination with epinephrine as Citanest Forte.

Prilocaine Uses:

• Local anesthesia:

  • It is used to produce local anesthesia in dentistry by nerve block or infiltration techniques.

Prilocaine (Citanest) Dose in Adults

Prilocaine (Citanest) Dose in the treatment of Dental anesthesia:

• Infiltration or conduction block:

  • Initial: 40 to 80 mg (1 to 2 mL) as a 4% solution.
  • As per AAPD guidelines, 2009, the maximum recommended dose (according to the weight) within a 2-hour period:
    • <70 kg: 6 mg/kg (400 mg)
    • ≥70 kg: 400 mg or 5 to 6 cartridges

Note:

• The effective dose of the drug varies with the procedure, the duration of anesthesia required, the intensity of anesthesia needed, and the physical condition of the patient. The lowest effective dose should be used.

Prilocaine (Citanest) Dose in Childrens

Prilocaine (Citanest) Dose in the treatment of Dental anesthesia: Infiltration or conduction block:

• Children younger than 10 years:

  • Doses exceeding 40 mg (1 mL) as a 4% solution per procedure are rarely required for procedures that involve a single tooth, procedures 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.

Pregnancy Risk Factor B

• Although it can cross the placental boundary, adverse fetal events have not been observed in animal reproduction studies.

Use during breastfeeding:

• It is unknown whether the drug will be excreted into breastmilk. It is recommended that pregnant women use it with caution.

Dose in Kidney disease:

There are no dosage adjustments provided in the manufacturer’s labeling. It is metabolized in the kidneys and should be used with caution in patients with kidney disease.

Dose in Liver disease:

There are no dosage adjustments provided in the manufacturer’s labeling. Although it is metabolized in the kidneys, it should be used with caution in patients with liver disease.

Side effects of Prilocaine (Citanest):

• 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

Contraindications to Prilocaine (Citanest):

• Allergy to any component or amide-type local anesthetic;
• Patients with congenital and idiopathic methemoglobinemia

Canadian labeling: Additional contraindications not in US labeling: Citanest Plain Dentist:

• Heart block or severe shock;
• Sepsis or inflammation at the injection site.

Warnings and precautions

• CNS toxicity:

  • Local anesthetic drugs can cause central nervous system toxicities. CNS toxicity can be symptomatic in the early stages.
  • These include restlessness, anxiety, dizziness and dizziness. It is important to receive supportive and symptomatic treatment.

• Methemoglobinemia:

  • Local anesthetic drugs have been linked to methemoglobinemia. 
  • Treatment should be stopped if methemoglobinemia is diagnosed as clinically serious.
  • Sometimes, methemoglobinemia can be delayed for hours after drug exposure.
  • Patients with these conditions should be closely monitored, as they could develop methemoglobinemia.
    • Glucose-6-phosphate dehydrogenase deficiency,
    • Congenital and idiopathic methemoglobinemia
    • Cardiac and pulmonary compromise
    • Exposition to oxidizing agents and their metabolites
    • Infants under 6 months old
  • Patients with methemoglobinemia should be closely monitored for symptoms such as fatigue, cyanosis and rapid pulse.
  • Patients with congenital or irreversible methemoglobinemia should avoid it.

• Respiratory arrest

  • Local anesthetics are rarely used to treat sudden respiratory arrest.

• Seizures:

  • It has been linked to systemic and seizures. Unintentional intravascular injections may have caused seizures.

• Cardiovascular disease

  • It should be used with caution for patients with severe shock, cardiovascular disease, and heart block.

• Familial malignant hyperthermia

  • Malignant hyperthermia could be caused by Prilocaine. Patients who have a history of hyperthermia in the family should avoid using it. 
  • Patients without a history of hyperthermia should be screened according to standard protocols.

• Hepatic impairment

  • The liver is responsible for the metabolism of amide-type anesthetics. Patients with liver disease should not use them.

Prilocaine: Drug Interaction

Monitoring parameters:

• Monitor the patient for neurological toxicity such as drowsiness and jitteriness.
• Before starting the procedure, make sure the area is properly anesthetized to avoid patients discomfort.

How to administer Prilocaine?

It is locally infiltrated into the area where the procedure is done or around the nerve in case of the nerve block.

Mechanism of action of Prilocaine (Citanest):

• It is a local anesthetic drug belonging to the amide class.
• It blocks neuronal polarization by blocking intracellular sodium channels and sodium inflow into the axon. 
• This blocks the propagation and generation of nerve impulses. 
• Once the drug is removed from its receptors, it is possible to reverse the action and restore neuronal function.

The beginning of action:

• Infiltration takes less than 2 minutes
• Inferior Alveolar Nerve Block: Less than 3 Minutes

Time:

• Inferior alveolar nerve block: about 2.5 hours
• Infiltration: Complete anesthesia for procedures lasting 20 minutes.

Distribution:

• It can cross the blood-brain barrier

Protein binding:

• 40% to 55% (alpha acid glycoprotein)

Metabolism:

• It is mainly metabolized in the liver and to a less extent in the kidneys.
• It is hydrolyzed by amidases to produce ortho-toluidine and N-propylalanine; these compounds may further undergo ring hydroxylation

Half-life elimination:

• 1.6 hours;
• The half-life may be prolonged in patients with liver or renal impairment.

Excretion:

• Urine (Less than 5% is excreted as unchanged drug)

International Brand Names of Prilocaine:

• Citanest Plain Dental
• 4% Citanest Plain Dental
• Dentsply Prilocaine HCl
• Baritekal
• Citanest
• Citanest Dental
• Prilotekal
• Takipril
• Takiprin
• Xylonest

Prilocaine Brand Names in Pakistan:

No Brands Available in Pakistan.