COCAINE

COCAINE
(koe-kane')
COCAINE HYDROCHLORIDe
Classifications: anesthetic, local;
Therapeutic:topical anesthetics
Prototype: Procaine
Pregnancy Category: C
Controlled Substance: Schedule II

Availability

4%, 10% topical solution

Action

Alkaloid obtained from leaves of Erythroxylon coca. Topical application blocks nerve conduction and produces surface anesthesia accompanied by local vasoconstriction. Exerts adrenergic effect by potentiating action of endogenous (and injected) epinephrine and norepinephrine, possibly by inhibiting reuptake of catecholamines into sympathetic nerve terminals. Topical form of cocaine is a local anesthetic.

Therapeutic Effect

Systemic absorption produces descending CNS stimulation, with intense, short-lived euphoria accompanied by indifference to pain or hunger and with illusions of great strength, endurance, and mental capacity, all the basis for drug abuse.

Uses

Surface anesthesia of ear, nose, throat, rectum, and vagina. Ophthalmic use largely abandoned because of its tendency to cause corneal sloughing. Sometimes used as ingredient in Brompton's cocktail.

Contraindications

Hypersensitivity to local anesthetics; sepsis in region of proposed application; acute MI, history of cardiac arrhythmias, cardiac disease; seizures or seizure disorders; thyrotoxicosis cerebrovascular disease; Tourette's syndrome; MAOI therapy; pregnancy (category C), lactation.

Cautious Use

History of drug sensitivities, history of drug abuse.

Route & Dosage

Surface Anesthesia
Adult: Topical 1–10% solution (use >4% solution with caution), max single dose of 1 mg/kg

Administration

Topical

Exercise caution to ensure that drug is taken as prescribed.
Preserve in tightly closed, light-resistant containers.

Adverse Effects (≥1%)

Body as a Whole: Formication ("cocaine bugs"), hypersensitivity reactions. CV: Tachycardia, ventricular fibrillation, MI, angina pectoris. GI: Nausea, vomiting, anorexia, abdominal pain. CNS: CNS stimulation and CNS depression (respiratory and circulatory failure). Respiratory: pneumonia, lung damage (chronic cocaine smoking). Special Senses: Runny nose, perforated nasal septum; clouding, pitting, and ulceration of cornea.

Interactions

Drug: Epinephrine entails risk of severe hypertension and arrhythmias; mao inhibitors potentiate pharmacologic effects of cocaine.

Pharmacokinetics

Absorption: Readily absorbed from mucous membranes; absorption limited by vasoconstriction. Onset: 1 min. Peak: 15–120 min. Duration: 30 min–2 h. Distribution: Crosses placenta; distributed into breast milk. Metabolism: Hydrolyzed in serum. Elimination: In urine; detectable for up to 30 h. Half-Life: 1–2.5 h.

Nursing Implications

Assessment & Drug Effects

When used for anesthesia of throat, cocaine causes temporary paralysis of cilia of respiratory tract cells, reducing protection against aspiration. It also may interfere with pharyngeal stage of swallowing. Give nothing by mouth until sensation returns.
Monitor cardiovascular status, especially in patients with known cardiac disease. Report promptly cardiac arrhythmias.

Patient & Family Education

Promptly report angina or chest pain or respiratory distress.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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