• Cocaine (crack, pasta, bazooka, snuff, coke, snow or white lady) is a colorless, odorless, crystalline substance with bitter taste and slightly soluble in water, but freely soluble in alcohol.
• alkaloid deliriant, obtained from dried leaves of  Erythroxylum coca
• Illicit forms: hydrochloride salt and its alkalization products,  freebase or crack.

Action

• Cocaine produces a hyperadrenergic state.
• Increases the synaptic concentrations of the  monoamine neurotransmitters dopamine, norepine-phrine and serotonin by binding to transporter proteins in presynaptic neurons and blocking uptake.
• local anesthetic, as it blocks initiation and conduction of nerve impulse by decreasing axonal
• membrane permeability to sodium ions.

Absorption and Excretion:

• rapidly absorbed from the mucous membranes and subcutaneous tissues.
• 30–50% of cocaine is metabolized by hepatic esterases and plasma pseudocholinesterase.

Signs and Symptoms:

• elevated pulse, blood pressure, respiration and temperature.

Onset occurs within

1. 7 seconds after inhalation.
2. 15  seconds after taking IV
3. 3 minutes after nasal insufflations
4.  10 min in oral ingestion

• Tea colored urine may indicate rhabdomyolysis and potential renal failure.
• In fatal cases, the onset and progression are accelerated, with convulsions and death (from
• respiratory failure, cerebral hemorrhage or cardiac failure) frequently occurring in 2–3 min.

Fatal dose:20 mg IV; 500 mg to 1.2 g orally.

Fatal period:Few minutes to 1–2 h.

Chronic  overuse can cause: 

• Psychotic  episodes: (Cocaine  psychosis)
• Persecutory  delusions with  tactile  hallucinations(formication).
• Tactile hallucinations: are manifested as  bugs  crawling  under  the skin.
• Cocaine  bugs  or magnan’s symptoms.
• Black pigmentation  of tongue  and teeth.

Withdrawal symptoms:

• Fatigue, dysphoria, disturbed  sleep.
• A combination  of  cocaine and heroin taken by  injection  is  called  speed  ball.

Treatment: There is no specific antidote. 

Postmortem Findings:

1. Patients may have linear excoriations, ‘crack pipe’ , burns on the fingers,or thumbs, the face and upper airway.
2. Track marks in the usual sites such as the antecubital fossae, and at unusual sites such as under the tongue and on top of the feet may be seen.
3. Intense asphyxial signs, and cardiac dilatation may be seen.

• Blood should be preserved by adding fluoride.