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Information

Author

Nabil Elkassabany , MD


TREATMENT

DRUGS

  • Usual dose:
    • Topical use 1-10% concentration, applied to desired mucosal area, not to exceed 1 mg/kg
    • Reduce dose in children and the elderly
    • Pregnancy class C, X for non-medical use
    • Breastfeeding contraindicated, excreted in breast milk

Mechanism of Action

  • Esteratic local anesthetic agent
  • Blocks voltage-gated sodium channels and inhibits depolarization, initiation, and conduction of nerve impulses
  • Blocks neuronal reuptake of norepinephrine resulting in CNS stimulation, tachycardia, hypertension, and vasoconstriction
  • Blocks neuronal reuptake of dopamine and serotonin in the midbrain, with resulting euphoria and arousal

Uses

  • Local anesthetic with vasoconstrictor activity, used on mucosal surfaces of the respiratory tract for otorhinolaryngology procedures and bronchoscopy
  • Used in combination with other agents (tetracaine-adrenaline-cocaine) for the repair of minor head and neck lacerations
  • Commonly abused CNS stimulant in the US (National Institute of Drug Abuse NIDA)

Onset

1 minute when applied to mucosa, peak effect in 5 minutes

Duration

Serum half-life of cocaine is 30-90 minutes

Metabolism

  • Non-enzymatic hydrolysis to benzoylecgonine, via hepatic esterases, or plasma pseudocholinesterases to ecgonine methylester, and minimal amounts by CYP3A4 to norcocaine, all of which are active and excreted in urine
  • Benzoylecgonine has the highest concentration in urine and can be detected for 2-3 days after exposure

Adverse Effects

Hypertension, tachycardia, dysrhythmias, myocardial ischemia, CNS stimulation, euphoria, hallucinations, paranoia, seizures, fever, agitation, restlessness, tremor, stroke, mydriasis, rhinitis, tachypnea, vasculitis, Raynaud's phenomenon

CLINICAL PEARLS