Cocaine poisoning

Introduction

Cocaine is an alkaloid derived from plant Erythroxylon coca.

It is produced as a salt (cocaine hydrochloride) or as an alkaloid known as freebase or crack.

It is a colorless, odorless, transparent, crystalline substance.

It makes cracking sound when heated, thus also known as crack.

It is usually adulterated with other substances such as caffeine, amphetamine, strychnine etc. When it is adulterated with heroin, it is called as speed ball.

Route of administration

• Chewing – coca leaves
• Pyrolysis (smoking)
• Snorting
• Intravenous injection
• Ingestion

Fatal dose

• Oral — 50 mg
• Mucosal — 100 mg

Fatal period

Few minutes to few hours

Absorption, metabolism and excretion

• Cocaine is well absorbed from oral, nasal and respiratory site.
• With intravenous injection or inhalation, the onset effects are rapid with peak level achieved in 3 to 5 minutes. The half-life is approximately 1 hour.
• It is metabolized by liver and plasma cholinesterase to benzoylecgonine, ecgonine methyl ester and ecgonine.
• The metabolites are excreted through urine.

Mode of Action

Cocaine is CNS stimulant. CNS stimulant effects and euphoria are mediated through inhibition of dopamine reuptake in the nucleus accumbens. However, in chronic cocaine user, it causes dopamine depletion and impairment of dopaminergic function in the brain.

Cocaine potentates’ nor-epinephrine and epinephrine. Cocaine blocks the reuptake of neurotransmitters at the synapse due to which there is increase in the concentration of nor-epinephrine and epinephrine. The increase in concentration of nor-epinephrine and epinephrine causes sympathomimetic effects such as tachycardia, hypertension, hyperthermia, diaphoresis, mydriasis and vasoconstriction.

Sign and symptoms

• Anxiety
• Agitation
• Restlessness
• Tremors
• Hyperthermia
• Tachycardia
• Hypertension
• Convulsions
• Hyperreflexia
• Psychosis
• Auditory or visual hallucinations
• Magnan’s symptom or cocaine bugs (formication).
• Mydriasis
• Pulmonary edema
• Rhabdomyolysis
• Intestinal ischemia/abdominal pain
• vasoconstriction.
• Myocardial ischemia/infarction due to coronary artery vasospasm.
• Intracranial hemorrhage such as subarachnoid hemorrhage.

Post mortem findings

• Signs of asphyxia
• Nasal septum ulceration and perforation may be seen in chronic snorting abuser.
• There may be multiple scar marks at injection site in chronic abuser.
• There may be infective endocarditis as sequelae to septic injection site and practice.
• Hepatic necrosis may be present especially in coca paste smokers.
• Heart may show evidence of myocardial infarction.
• Lymphocytic infiltrate, coagulative necrosis of myocardial fibers and intimal proliferation are also seen.

Medico legal aspects

• Drug of abuse
• Body may get decompose rapidly.
• Accidental deaths are common due to overdose or adulteration.
• Provoke the users for violent behaviour.
• Acute intoxication may cause person to be aggressive and paranoid.
• Prostitutes may place cocaine solution into vagina to produce local constriction and causes intoxication.

Forensic examination

• Thin layer chromatography.
• Gas chromatography
• UV and IR spectrophotometer
• NMR