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What is the primary cardiovascular effect of cocaine following initial exposure?
What is the primary cardiovascular effect of cocaine following initial exposure?
Which mechanism explains the cardio-stimulatory effect of cocaine?
Which mechanism explains the cardio-stimulatory effect of cocaine?
What contributes to hyperthermia in cocaine acute poisoning?
What contributes to hyperthermia in cocaine acute poisoning?
Which of the following is NOT a CNS effect of cocaine poisoning?
Which of the following is NOT a CNS effect of cocaine poisoning?
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What is one potential ophthalmologic effect of smoking crack cocaine?
What is one potential ophthalmologic effect of smoking crack cocaine?
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Which cardiovascular condition can result from chronic cocaine use?
Which cardiovascular condition can result from chronic cocaine use?
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Which statement about cocaine's sympathomimetic effects is false?
Which statement about cocaine's sympathomimetic effects is false?
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What condition can result from cocaine-induced coronary artery vasoconstriction?
What condition can result from cocaine-induced coronary artery vasoconstriction?
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What is a common use of cocaine in medicine?
What is a common use of cocaine in medicine?
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What form of cocaine is most popularly used recreationally?
What form of cocaine is most popularly used recreationally?
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Which method of cocaine intake is less common?
Which method of cocaine intake is less common?
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What is the typical purity range of street cocaine?
What is the typical purity range of street cocaine?
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What neurotransmitter's reuptake is primarily inhibited by cocaine?
What neurotransmitter's reuptake is primarily inhibited by cocaine?
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What effect does cocaine have on excitatory amino acids?
What effect does cocaine have on excitatory amino acids?
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How do dopamine receptor agonists affect cocaine craving?
How do dopamine receptor agonists affect cocaine craving?
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Which mechanism allows cocaine to produce a local anesthetic effect?
Which mechanism allows cocaine to produce a local anesthetic effect?
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What serious cardiovascular event can occur as a complication of cocaine use?
What serious cardiovascular event can occur as a complication of cocaine use?
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What is a pulmonary effect of cocaine use?
What is a pulmonary effect of cocaine use?
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What can cause rhabdomyolysis associated with cocaine use?
What can cause rhabdomyolysis associated with cocaine use?
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What limitation does urine testing for cocaine have?
What limitation does urine testing for cocaine have?
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How long can benzoylecgonine, a metabolite of cocaine, be detected in urine after use?
How long can benzoylecgonine, a metabolite of cocaine, be detected in urine after use?
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Which factor can lead to false-negative urine testing for cocaine?
Which factor can lead to false-negative urine testing for cocaine?
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Which of the following is true regarding testing for cocaine?
Which of the following is true regarding testing for cocaine?
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Which condition can be a result of thermal injuries due to cocaine-related incidents?
Which condition can be a result of thermal injuries due to cocaine-related incidents?
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What does a conversion from a negative study on admission to a positive study suggest?
What does a conversion from a negative study on admission to a positive study suggest?
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Which testing method is emphasized as more useful than urine drug screening for suspected cocaine toxicity?
Which testing method is emphasized as more useful than urine drug screening for suspected cocaine toxicity?
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What initial intervention should be prioritized for patients with cocaine toxicity?
What initial intervention should be prioritized for patients with cocaine toxicity?
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Why is succinylcholine considered a relative contraindication in cocaine toxicity cases?
Why is succinylcholine considered a relative contraindication in cocaine toxicity cases?
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What should be administered if hypotension is present in a cocaine toxicity patient?
What should be administered if hypotension is present in a cocaine toxicity patient?
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Which cardiac condition may be indicated by an ECG in patients with cocaine toxicity?
Which cardiac condition may be indicated by an ECG in patients with cocaine toxicity?
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What is the primary reason for monitoring core temperature in cocaine toxicity patients?
What is the primary reason for monitoring core temperature in cocaine toxicity patients?
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Which cardiac markers are preferred over others in assessing cocaine-related muscle injury?
Which cardiac markers are preferred over others in assessing cocaine-related muscle injury?
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What is the preferred method for cooling an individual with hyperthermia?
What is the preferred method for cooling an individual with hyperthermia?
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Why are antipyretics not appropriate for treating hyperthermia?
Why are antipyretics not appropriate for treating hyperthermia?
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Which benzodiazepine is preferable for rapid onset and easy titration?
Which benzodiazepine is preferable for rapid onset and easy titration?
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What should be avoided in the management of hypertension and tachycardia in hyperthermic patients?
What should be avoided in the management of hypertension and tachycardia in hyperthermic patients?
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What is a potential adverse effect of using chlorpromazine in hyperthermic patients?
What is a potential adverse effect of using chlorpromazine in hyperthermic patients?
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What is the primary reason for using phentolamine in vasospasm management?
What is the primary reason for using phentolamine in vasospasm management?
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What could be a consequence of using phenothiazines in a patient with hyperthermia?
What could be a consequence of using phenothiazines in a patient with hyperthermia?
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How is diazepam administered when treating hyperthermia?
How is diazepam administered when treating hyperthermia?
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Study Notes
Cocaine Toxicity
- Cocaine is a naturally occurring alkaloid with local anesthetic and sympathomimetic activity.
- Cocaine is found in the leaves of Erythroxylum coca.
- Cocaine is usually abused by chewing coca leaves, smoking coca paste, or snorting cocaine hydrochloride.
- Cocaine hydrochloride is the most popular form of cocaine intake.
- Street cocaine is often impure, with pure cocaine content ranging from 10 to 50 percent, most commonly 15 to 20 percent.
- Cocaine is often adulterated with compounds like talc, lactose, sucrose, glucose, mannitol, inositol, caffeine, procaine, phencyclidine, lignocaine, strychnine, amphetamine, or heroin.
Neurotransmitter Effects
- Cocaine blocks the reuptake of biogenic amines, including serotonin and catecholamines (dopamine, norepinephrine, and epinephrine).
- Cocaine's CNS stimulant effects are mediated through the inhibition of dopamine reuptake.
- Cocaine binds strongly to the dopamine-reuptake transporter, blocking reuptake and leading to high dopamine concentrations in the synapse.
- Cocaine also increases the concentrations of excitatory amino acids (aspartate and glutamate), which further increase dopamine levels.
Cardiovascular Effects
- The initial effect of cocaine on the cardiovascular system is bradycardia, but it is too transient to be clinically evident.
- Tachycardia becomes the prominent effect due to central sympathetic stimulation.
- The cardio-stimulatory effect of cocaine is due to sensitization to adrenaline and noradrenaline, preventing their reuptake and increasing their release from adrenergic nerve terminals.
- Cocaine's sympathomimetic effects lead to increased myocardial oxygen demand, alpha-adrenergic mediated coronary vasoconstriction, inhibition of endogenous fibrinolysis, and increased thrombogenicity.
Clinical Features
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Acute Poisoning:
- Hyperthermia: Results from increased heat production, diminished heat dissipation, direct pyrogenic effect, and stimulation of calorigenic activity of the liver.
- Body Temperature: Often reaches 42.2 to 44.4°C and doesn't respond to conventional antipyretics. Associated with rhabdomyolysis, seizures, and renal failure.
- CNS Effects: Headache, anxiety, agitation, hyperactivity, restlessness, tremor, hyperreflexia, convulsions, and pseudo-hallucinations.
- Ophthalmologic Effects: Mydriasis, loss of eyebrow and eyelash hair from smoking crack cocaine, corneal abrasions/ulcerations, central retinal artery occlusion, and bilateral blindness.
- CVS Effects: Tachycardia, systemic arterial hypertension, coronary artery vasoconstriction with myocardial ischemia and infarction, tachyarrhythmia, chronic dilated cardiomyopathy, aortic dissection and rupture, and sudden cardiac death.
- Pulmonary Effects: Thermal injuries to the upper airway, exacerbation of asthma, non-cardiogenic pulmonary edema, and diffuse alveolar hemorrhage.
- Musculoskeletal Effects: Rhabdomyolysis with hyperthermia, massive elevation of creatine phosphokinase, and acute renal failure.
Diagnostic Testing
- Cocaine and benzoylecgonine, its primary metabolite, can be detected in blood, urine, saliva, hair, and meconium.
- Routine drug-of-abuse testing relies on urine testing using immunologic techniques.
- Cocaine is rapidly eliminated within hours, but benzoylecgonine can be detected in urine for 2-3 days.
- Cocaine metabolites can be identified for weeks in chronic users with sophisticated testing.
Urine Testing Limitations
- Offers limited information for managing patients with presumed cocaine toxicity.
- Can't distinguish recent from remote cocaine use.
- False-negative testing may occur with large urine volume, recent cocaine use, or intentional dilution.
- False-positive tests are more common with hair testing due to external contamination.
Management
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General Supportive Care:
- Initial focus on stabilizing the patient's airway, breathing, and circulation.
- Succinylcholine use may be contraindicated in the setting of rhabdomyolysis due to potential hyperkalemia.
- For hypotension, infuse intravenous 0.9% sodium chloride solution as many patients are volume depleted.
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Elevated Temperature:
- Critical vital sign abnormality.
- Rapid cooling with ice water immersion or mist and fanning is required to achieve a rapid return to normal core body temperature.
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Pharmacotherapy:
- Antipyretics, drugs preventing shivering, and dantrolene are not indicated.
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Benzodiazepines:
- Parenteral therapy with a rapid onset and peak action is preferred for titration (midazolam or diazepam).
- Large doses may be necessary (on the order of 1 mg/kg of diazepam).
-
Phenothiazines or Butyrophenones:
- Contraindicated as they enhance toxicity, increase lethality, interfere with heat dissipation, exacerbate tachycardia, prolong the QT interval, induce torsade de pointes, and precipitate dystonic reactions.
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Hypertension and Tachycardia:
- Usually respond to sedation and volume repletion.
- If persistent, direct-acting vasodilators (nitroglycerin, nitroprusside, nicardipine) or alpha-adrenergic antagonists (phentolamine) may be considered.
Specific Management
- End-organ manifestations of vasospasm not resolving with sedation, cooling, and volume resuscitation can be treated with vasodilators (phentolamine).
- Phentolamine can be dosed intravenously in increments of 1-2.5 mg and repeated until symptom resolution or systemic hypotension develops.
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Description
This quiz explores the toxicity of cocaine, its forms, and methods of use. Additionally, it discusses its impact on neurotransmitters, particularly focusing on dopamine reuptake inhibition. Test your knowledge on this powerful stimulant and its implications on the central nervous system.
