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Amphetamine Poisoning, Emergency Medicine

Basics

Description

- "Designer drugs"пїЅ: - Variants of illegal parent drugs - Often synthesized in underground labs - "Crystal,"пїЅ "Ice"пїЅ: - Crystalline methamphetamine hydrochloride - Smoked, insufflated, or injected - Rapid onset; duration several hours

- "Crank"пїЅ - "Ecstasy"пїЅ (3,4-methylenedioxymethamphetamine, MDMA, XTC, E): - Often used at dances and "rave"пїЅ parties - Dehydration can lead to hyperthermia, hyponatremia, fatality

- MDA (3,4,-methylenedioxyamphetamine) - Methcathinone ("cat,"пїЅ "Jeff,"пїЅ "mulka"пїЅ): - Derivative of cathinone, found in the evergreen tree Catha edulis - Frequently synthesized in home labs - Does not show up on urine toxicology screens

- Determine the type, amount, timing, and route of amphetamine exposure - Assess for possible coingestions - Evaluate for symptoms of end organ injury: - Chest pain - Shortness of breath - Headache, confusion, and vomiting

- Common findings include: - Agitation - Tachycardia - Diaphoresis - Mydriasis

- Hypotension and respiratory distress may precede cardiovascular collapse - Evaluate for associated conditions: - Cellulitis and soft tissue infections - Diastolic cardiac murmurs or unequal pulses - Examine carefully for trauma - Pneumothorax from inhalation injury - Focal neurological deficits

- Vital signs: - Temperature >40 пїЅC: - Core temperature recording essential - Peripheral temperature may be cool - Indication for urgent cooling - Ominous prognostic sign

- ECG: - Signs of cardiac ischemia - Ventricular tachydysrhythmias - Reflex bradycardia

- Hyperthermia: - Benzodiazepines if agitated - Active cooling if temperature >40 пїЅC: - Tepid water mist - Evaporate with fan.

- Paralysis: - Indicated if muscle rigidity and hyperactivity contributing to persistent hyperthermia - Nondepolarizing agent (e.g., vecuronium) - Avoid succinylcholine. - Intubation; mechanical ventilation

  • Increased release of norepinephrine, dopamine, and serotonin
  • Decreased catecholamine reuptake
  • Direct effect on О±- and β-adrenergic receptors

Etiology

  • Prescription drugs:Amphetamine (Benzedrine)Dextroamphetamine (Dexedrine)Diethylpropion (Tenuate)Fenfluramine (Pondimin)MethamphetamineMethylphenidate (Ritalin)Phenmetrazine (Preludin)Phentermine
  • "Designer drugs"пїЅ:Variants of illegal parent drugsOften synthesized in underground labs"Crystal,"пїЅ "Ice"пїЅ:Crystalline methamphetamine hydrochlorideSmoked, insufflated, or injectedRapid onset; duration several hours"Crank"пїЅ"Ecstasy"пїЅ (3,4-methylenedioxymethamphetamine, MDMA, XTC, E):Often used at dances and "rave"пїЅ partiesDehydration can lead to hyperthermia, hyponatremia, fatalityMDA (3,4,-methylenedioxyamphetamine)Methcathinone ("cat,"пїЅ "Jeff,"пїЅ "mulka"пїЅ):Derivative of cathinone, found in the evergreen tree Catha edulisFrequently synthesized in home labsDoes not show up on urine toxicology screensMephedroneMay be contained in "bath salts"пїЅ

Diagnosis

Signs and Symptoms

  • CNS:AgitationDeliriumHyperactivityTremorsDizzinessMydriasisHeadacheChoreoathetoid movementsHyperreflexiaCerebrovascular accidentSeizures and status epilepticusComa
  • Psychiatric:EuphoriaIncreased aggressivenessAnxietyHallucinations (visual, tactile)Compulsive repetitive actions
  • Cardiovascular:PalpitationsHypertensive crisisTachycardia or (reflex) bradycardiaDysrhythmias (usually tachydysrhythmias)Cardiovascular collapse
  • Other:RhabdomyolysisMyoglobinuriaAcute renal failureAnorexiaDiaphoresisDisseminated intravascular coagulation (DIC)

History

  • Determine the type, amount, timing, and route of amphetamine exposure
  • Assess for possible coingestions
  • Evaluate for symptoms of end organ injury:Chest painShortness of breathHeadache, confusion, and vomiting

Physical Exam

  • Common findings include:AgitationTachycardiaDiaphoresisMydriasis
  • Severe intoxication characterized by:TachycardiaHTNHyperthermiaAgitated deliriumSeizuresDiaphoresis
  • Hypotension and respiratory distress may precede cardiovascular collapse
  • Evaluate for associated conditions:Cellulitis and soft tissue infectionsDiastolic cardiac murmurs or unequal pulsesExamine carefully for traumaPneumothorax from inhalation injuryFocal neurological deficits

Essential Workup

  • Vital signs:Temperature >40 пїЅC:Core temperature recording essentialPeripheral temperature may be coolIndication for urgent coolingOminous prognostic signBP:Severe hypertension can lead to cardiac and neurologic abnormalities.Late in course, hypotension may supervene due to catecholamine depletion
  • ECG:Signs of cardiac ischemiaVentricular tachydysrhythmiasReflex bradycardia

Diagnosis Tests & Interpretation

Lab

  • Urinalysis:
  • Electrolytes, BUN/creatinine, glucose:Hypoglycemia may contribute to altered mental status.Acidosis may accompany severe toxicity.Rhabdomyolysis may cause renal failure.Hyperkalemia-life-threatening consequence of acute renal failure
  • Coagulation profile to monitor for potential DIC:
  • Creatine phosphokinase (CPK):Markedly elevated in rhabdomyolysis
  • Urine toxicology screen:For other toxins with similar effects (e.g., cocaine)Some amphetamine-like substances (e.g., methcathinone) may not be detected.
  • Aspirin and acetaminophen levels if suicide attempt is a possibility
  • Arterial blood gas (ABG)

Imaging

  • Chest radiograph:Adult respiratory distress syndromeNoncardiogenic pulmonary edema
  • Head CT for:Significant headacheAltered mental statusFocal neurologic signsFor subarachnoid hemorrhage, intracerebral bleed

Diagnostic Procedures/Surgery

Lumbar puncture for: пїЅ

  • Suspected meningitis (headache, altered mental status, hyperpyrexia)
  • Suspected subarachnoid hemorrhage and CT normal

Differential Diagnosis

  • Sepsis
  • Thyroid storm
  • Serotonin syndrome
  • Neuroleptic malignant syndrome
  • Pheochromocytoma
  • Subarachnoid hemorrhage
  • Drugs that cause delirium:Anticholinergics:Belladonna alkaloidsAntihistaminesTricyclic antidepressantsCocaineEthanol withdrawalSedative/hypnotic withdrawalHallucinogensPhencyclidine
  • Drugs that cause HTN and tachycardia:SympathomimeticsAnticholinergicsEthanol withdrawalPhencyclidineCaffeinePhenylpropanolamineEphedrineMonoamine oxidase inhibitorsTheophyllineNicotine
  • Drugs that cause seizures:Carbon monoxideCarbamazepineCyanideCocaineCholinergics (organophosphate insecticides)CamphorChlorinated hydrocarbonsEthanol withdrawalSedative/hypnotic withdrawalIsoniazidTheophyllineHypoglycemicsLeadLithiumLocal anestheticsAnticholinergicsPhencyclidinePhenothiazinesPhenytoinPropoxypheneSalicylatesStrychnine

Treatment

Pre-Hospital

  • Patient may be uncooperative or violent.
  • Secure IV access.
  • Protect from self-induced trauma.

Initial Stabilization/Therapy

  • ABCs
  • Establish IV 0.9% NS access.
  • Cardiac monitor
  • Naloxone, dextrose (or Accu-Chek), and thiamine if altered mental status

Ed Treatment/Procedures

  • Decontamination:Administration of activated charcoalWhole-bowel irrigation with polyethylene glycol solution for body packers
  • Hypertensive crisis:Initially administer benzodiazepines if agitated.О±-blocker (phentolamine) as second-line agentNitroprusside for severe, unresponsive hypertensionAvoid β-blockers, which may exacerbate hypertension.
  • Agitation, acute psychosis:Administer benzodiazepines.
  • Hyperthermia:Benzodiazepines if agitatedActive cooling if temperature >40 пїЅC:Tepid water mistEvaporate with fan.Paralysis:Indicated if muscle rigidity and hyperactivity contributing to persistent hyperthermiaNondepolarizing agent (e.g., vecuronium)Avoid succinylcholine.Intubation; mechanical ventilationApply cooling blankets.
  • Rhabdomyolysis:Administer benzodiazepines.Hydrate with 0.9% NS.Maintain urine output at 1-2 mL/min.Hemodialysis (if acute renal failure and hyperkalemia occur)
  • Seizures:Maintain airway.Administer benzodiazepines.Phenobarbital if unresponsive to benzodiazepinesPhenytoin contraindicated
  • Hypotension:May be late finding due to catecholamine depletionInitially bolus with isotonic crystalloid solutionIf no response, administer norepinephrine.Dopamine may not be effective

Medication

  • Activated charcoal: 1-2 g/kg up to 100 g PO
  • Dextrose: D50W 1 amp: 50 mL or 25 g (peds: D25W 2-4 mL/kg) IV
  • Diazepam (benzodiazepine): 5-10 mg (peds: 0.2-0.5 mg/kg) IV
  • Lorazepam (benzodiazepine): 2-6 mg (peds: 0.03-0.05 mg/kg) IV
  • Nitroprusside: 1-8 Ојg/kg/min IV (titrated to BP)
  • Phenobarbital: 15-20 mg/kg at 25-50 mg/min until cessation of seizure activity
  • Phentolamine: 1-5 mg IV over 5 min (titrated to BP)
  • Vecuronium: 0.1 mg/kg IVP

Follow-Up

Disposition

Admission Criteria

  • Hyperthermia
  • Persistent altered mental status
  • Hypertensive crisis
  • Seizures
  • Rhabdomyolysis
  • Persistent tachycardia

Discharge Criteria

  • Asymptomatic after 6 hr observation
  • Absence of the above admission criteria

Followup Recommendations

Patients may need referral for chemical dependency rehab and detoxification. пїЅ

Pearls and Pitfalls

  • Admit patients with severe or persistent symptoms.
  • Monitor core temperature:Hyperthermia >40 пїЅC may be life threatening.Treat with aggressive sedation and active cooling.Recognize rhabdomyolysis and hyperkalemia.Avoid physical restraints in agitated patients if possible.
  • Consider associated emergency conditions:Patients with chest pain should be evaluated for acute coronary syndromes and treated accordingly.Consider infection in altered patients with fever and history of IV drug use.Methamphetamine abuse frequently associated with traumatic injury
  • Benzodiazepines are 1st-line therapy in symptomatic methamphetamine intoxication

Additional Reading

  • Callaway пїЅCW, Clark пїЅRF. Hyperthermia in psychostimulant overdose. Ann Emerg Med. 1994;24:68-75.
  • Carvalho пїЅM, Carmo пїЅH, Costa пїЅVM, et al. Toxicity of amphetamines: an update. Arch Toxicol. 2012;86:1167-1231.
  • Gray пїЅSD, Fatovich пїЅDM, McCoubrie пїЅDL, et al. Amphetamine-related presentations to and inner-city tertiary emergency department: A prospective evaluation. Med J Aust. 2007;186:336.
  • Prosser пїЅJM, Nelson пїЅLS. The toxicology of bath salts: a review of synthetic cathinones. J Med Toxicol. 2012;8:33-42.
  • Turnipseed пїЅSD, Richards пїЅJR, Kirk пїЅJD, et al. Frequency of acute coronary syndrome in patients presenting to the emergency department with chest pain after methamphetamine use. J Emerg Med. 2003;24(4):369-373.

See Also (Topic, Algorithm, Electronic Media Element)

  • Sympathomimetic Poisoning
  • Tricyclic Antidepressant Poisoning

Codes

ICD9

  • 969.72 Poisoning by amphetamines
  • 969.73 Poisoning by methylphenidate
  • 969.79 Poisoning by other psychostimulants
  • 969.70 Poisoning by psychostimulant, unspecified

ICD10

  • T43.601A Poisoning by unsp psychostim, accidental, init
  • T43.621A Poisoning by amphetamines, accidental (unintentional), init
  • T43.631A Poisoning by methylphenidate, accidental, init
  • T43.691A Poisoning by oth psychostim, accidental, init

SNOMED

  • 45775001 Poisoning by amphetamine (disorder)
  • 216559001 Accidental poisoning by amphetamine (disorder)
  • 291258000 Accidental ecstasy poisoning (disorder)
  • 291242003 Amphetamine poisoning of undetermined intent (disorder)