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Questions and Answers
Cocaine is an alkaloid derived from the Erythroxylon coca plant.
Cocaine is an alkaloid derived from the Erythroxylon coca plant.
True
Amphetamines are synthetic analogs of ephedrine and have no medical uses.
Amphetamines are synthetic analogs of ephedrine and have no medical uses.
False
Cocaine powder is created by mixing coca paste with hydrochloric acid.
Cocaine powder is created by mixing coca paste with hydrochloric acid.
True
Caffeine is classified as a psychostimulant and is derived from tea leaves.
Caffeine is classified as a psychostimulant and is derived from tea leaves.
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The primary medical use of cocaine is to increase heart rate.
The primary medical use of cocaine is to increase heart rate.
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Methamphetamines and methylphenidate have significantly different chemical structures.
Methamphetamines and methylphenidate have significantly different chemical structures.
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Crack cocaine is a form of cocaine that is made smokable by using baking soda.
Crack cocaine is a form of cocaine that is made smokable by using baking soda.
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Psychostimulants like cocaine do not affect the sympathetic nervous system.
Psychostimulants like cocaine do not affect the sympathetic nervous system.
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Cocaine has a half-life of approximately 50-90 minutes.
Cocaine has a half-life of approximately 50-90 minutes.
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Amphetamines have a longer half-life than cocaine, lasting approximately 5-10 hours.
Amphetamines have a longer half-life than cocaine, lasting approximately 5-10 hours.
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Cocaethylene is formed when cocaine and alcohol are consumed together, and it has a shorter half-life than cocaine.
Cocaethylene is formed when cocaine and alcohol are consumed together, and it has a shorter half-life than cocaine.
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Cocaine primarily acts as an indirect agonist for serotonin with high affinity.
Cocaine primarily acts as an indirect agonist for serotonin with high affinity.
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Dry skin is often associated with sympathomimetic effects.
Dry skin is often associated with sympathomimetic effects.
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Cocaine automatically metabolizes in blood as well as in the liver.
Cocaine automatically metabolizes in blood as well as in the liver.
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Cocaine can lead to dangerous cardiac dysrhythmias, including wide complex tachycardia.
Cocaine can lead to dangerous cardiac dysrhythmias, including wide complex tachycardia.
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It is recommended to administer beta-blockers in cases of cocaine-induced hypertension.
It is recommended to administer beta-blockers in cases of cocaine-induced hypertension.
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Study Notes
Psychostimulants: Cocaine, Amphetamines
- Psychostimulants include cocaine and amphetamines.
- Learning objectives include familiarisation with common types, understanding mechanisms of action, and describing side effects.
- CNS stimulants include cocaine, crack cocaine (freebase or hydrochloride), D-amphetamine, methamphetamine, methylphenidate (Preludin), methylenedioxymethamphetamine ("ecstasy"), cathinone, methcathinone, methylxanthines (caffeine, theophylline, theobromide).
Cocaine Overview
- Cocaine is an alkaloid from the Erythroxylon coca plant, native to South America.
- Coca leaves are used for religious, mystical, social, stimulant, and medicinal purposes.
- Main stimulant uses include endurance, feeling of well-being (euphoria), and alleviating hunger.
- Medical uses include local anesthetic and vasoconstrictor (nasal congestion).
Cocaine Production
- Cocaine paste is extracted from soaked and mashed coca leaves (60-80% cocaine).
- Cocaine powder is made by mixing the paste with hydrochloric acid.
- Freebase/crack cocaine is extracted from the powder with baking soda. It is smokable.
Amphetamine Overview
- Amphetamines are synthetic analogs of ephedrine and are the active ingredient in mahuang.
- Mahuang was historically used in China for asthma.
- Related drugs, like methamphetamine and methylphenidate (Ritalin), are chemically similar.
- Medical uses for amphetamines include obesity, ADHD, and narcolepsy.
Chemical Structure of Stimulants
- Images of the chemical structures for cocaine, amphetamine, methamphetamine, and methylphenidate are provided in the presentation.
Neurophysiology: Cocaine
- Cocaine blocks the reuptake of norepinephrine, causing it to remain at the synaptic membrane.
Cocaine Pharmacology by Route of Administration
- Different routes of administration result in varying onset and peak effect times for cocaine.
- Onset of action and peak effect time for inhalation, intranasal, intravenous, and oral consumption are presented.
- Subcutaneous administration stays longer compared to other routes.
Effects on Mind, Brain, Behavior
- Psychostimulant effects are shown in an increase/decrease table. Increases include alertness, concentration, sensory awareness, euphoria, brain electrical activity, self-confidence, and decreased appetite, brain blood flow, glucose metabolism.
- Decreases include: anxiety, suspiciousness, paranoia, convulsions, tremor, seizures, psychosis, delirium, difficulty with multitasking, judgment and difficulty staying in one place. Reinforcement and addiction are also listed as possible consequences.
Peripheral Effects (sympathomimetic)
- Psychostimulants can trigger the fight-or-flight response (sympathetic nervous system arousal).
- Increases include blood pressure, blood sugar, heart rate, irregular heartbeats, vasoconstriction, body temperature, and bronchodilation. Impaired breathing is also a potential side effect.
- The cause of death from excessive stimulant use can be ventricular tachycardia, triggered by effects on the AV node and sodium channels.
Sympathomimetic Toxidrome
- Avoid beta-blockers during this condition, as unopposed alpha receptor stimulation results in hypertension, tachycardia, hyperthermia, and mydriasis.
- A related anticholinergic toxicrome is identifiable with dry skin and reduced bowel sounds.
- Different effects on the central nervous system are noted.
Cocaine Cardiac Features
- Cocaine can induce various cardiac dysrhythmias due to sodium and potassium blockade. These can include supraventricular tachycardia, atrial fibrillation/flutter, and wide complex tachycardia.
- Note that wide or prolonged QRS complexes are a significant danger.
Cocaine Pharmacokinetics: Absorption
- Routes of administration include insufflation, IV, inhalation, and oral.
Pharmacokinetics: Distribution and Metabolism
- Cocaine and amphetamines readily penetrate the blood-brain barrier (BBB).
- Cocaine has a half-life of roughly 50-90 minutes.
- Amphetamine half-life and meth half-life are noted.
- Metabolism produces active and inactive compounds, and cocaine also autometabolizes. Metabolites include norcocaine, ecgonine methyl ester, benzoylecgonine.
Cocaethylene
- Alcohol inhibits cocaine metabolism, increasing duration of action.
- Alcohol and cocaine react to create cocaethylene, a new psychoactive compound.
- Cocaethylene has effects similar to cocaine but greater potential cardiac toxicity.
Cocaine Pharmacodynamics
- Cocaine is an indirect agonist for dopamine, norepinephrine, and serotonin (5-HT). It blocks monoamine reuptake.
Amphetamine Pharmacodynamics
- Amphetamines are indirect agonists for dopamine and norepinephrine
- They have lower affinity for serotonin
- Amphetamines block monoamine reuptake, inhibit vesicular storage, inhibit MAO metabolism, and reverse reuptake.
Withdrawal
- Withdrawal from psychostimulants can include mild to moderate physical symptoms, and a dysphoric syndrome. Dysphoric syndrome is characterized by decreased activity, low motivation, and intense cravings.
- Symptom duration varies greatly, and can last from one week to several.
KHAT
- Khat (Catha edulis) ingestion in large quantities can lead to sympathomimetic effects, seizures, and cardiac arrhythmias.
- Addiction is often physiological.
Causes of Stimulant-Induced Chest Pain
- Stimulant use can result in noncardiac conditions (e.g. pneumothorax, foreign body aspiration, infections)
- Cardiac ischemia (or infarction) from vasoconstriction is a major concern.
Sympathomimetic Treatment
- First-line treatment for stimulant-related toxicity is benzodiazepines.
- Seizures - benzodiazepines (or propofol)
- Beta-blockers are contraindicated for unopposed alpha stimulation. Use phentolamine to block alpha effects.
- Cocaine-induced wide complex tachycardia requires sodium bicarbonate plus alprazolam (or other benzodiazepines to treat panic attacks).
- Hypertension unresponsive to benzodiazepines may require phentolamine.
- Treatment for decontamination (e.g. whole bowel irrigation) can be required when a large quantity of cocaine is involved.
- Activated charcoal can be used for prevention of amphetamine toxicity.
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Description
This quiz explores psychostimulants including cocaine and amphetamines. You will learn about their mechanisms of action, side effects, and various types used both recreationally and medically. Delve into the origins of cocaine and its production process.
