Drugs of Abuse
Synthetic Cannabinoids (Spice, K2)
- Symptoms: anxiety, paranoia, tachycardia
- Unique symptoms compared to traditional cannabinoids: psychosis, seizure, diaphoresis
Hallucinogenic amphetamines (ecstasy, MDMA)
- Increased serotonergic activity
- Management: supportive care (IVF, cooling for hyperthermia), benzodiazepines
Gamma-hydroxybutyrate (GHB)
- Symptoms: euphoria, hypersexuality, rapid onset/clearance
- Signs: bradycardia, bradypnea, coma with rapid awakening
- Management: intubation for depressed GCS
- Withdrawal: symptoms and treatment identical to ethanol withdrawal, consider baclofen
Cathinone (bath salts)
- Symptoms: hallucinations
- Signs: tachycardia, hypertension, tremor, mydriasis, diaphoresis, hyperthermia, bruxism
- Management: benzodiazepines, consider paralysis, avoid beta-blockers
Cocaine
- MOA: increase catecholamines, Na-channel blockade
- Toxicity: HTN, tachycardia, hyperthermia, rhabdomyolysis, MI, seizure, VT
- Management: benzodiazepines, cooling, anti-hypertensives (nitrate, CCB, not B-blocker)
Amphetamine
- Toxicity: HTN, tachycardia, hyperthermia, rhabdomyolysis, intracranial hemorrhage
- Management: same as cocaine
Benzodiazepines
- Toxicity: sedation, respiratory depression
- Management: consider flumazenil 0.2mg IV q1min x1-5
Toxic Alcohols
- Overview
- Toxic metabolites produced by alcohol dehydrogenase which can be inhibited by ethanol or fomepizole
- Fomepizole: 15mg/kg loading dose, 10mg/kg q12h x4 doses then 15mg/kg q12h (stimulates own metabolism); if dialysis, q4h
- Diagnosis: osmolar gap (>14), 2Na + Glu/18 + BUN/2.8 + EtOH/4.6
- Treatment
- ADH inhibition
- HCO3
- Hemodialysis
- Supportive care
- Hypoglycemia: dextrose
Methanol
- Component of antifreeze, windshield washer fluid
- Metabolite formic acid which causes acidosis and blindness
- Can give folate
Ethylene glycol
- Component of antifreeze, automobile coolants, de-icing agents
- Metabolite oxalic acid which precipitates calcium oxalate crystals and causes acute renal failure
- Can give thiamine (100mg q6h), pyridoxine (500mg q6h), Mg
Isopropanol
- Component of rubbing alcohol
- Metabolite acetone which does not cause acidosis
Analgesics
Acetaminophen
- Metabolism: glucoronidation, CYP450
- CYP450 pathway produces toxic metabolite when glucoronidation overwhelmed
- In pediatrics, sulfation process protective
- Toxic dose: >150mg/kg, >3g/day
- Injury: liver (centrilobular necrosis), renal, pancreatic
- Increased risk: induced CYP450 (chronic EtOH, rifampin, anti-epileptics)
- Nomogram: applicable to single ingestion at 4-hours
- Labs: PT/INR, LFT, lipase, chemistry
- Management: NAC
- PO: 140mg/kg, 70mg/kg q4h
- IV: 150mg/kg, 50mg/kg over 4h, 100mg/kg over 16h
NSAID
- Symptoms
- Acute: GI upset, low risk UGIB
- Acute massive: acidosis, coma, seizures
- Chronic: UGIB, nephropathy, agranulocytosis
Aspirin
- Signs: tachycardia, hyperthermia, tachypnea/hyperpnea
- Severe: cerebral and pulmonary edema, CNS hypoglycemia
- Labs: primary respiratory alkalosis with metabolic acidosis
- Management
- Hypoglycemia (CNS) treatment
- Bicarbonate infusion (urine pH > 8)
- Hemodialysis for pulmonary edema, cerebral edema, renal failure, acidemia, level >100mg/dL (acute) or > 60mg/dL (chronic)
Opioids
- Symptoms: respiratory depression, miosis
- Management: naloxone 0.04mg, 0.4mg, 2mg
- Withdrawal: nausea/vomiting, diarrhea, abdominal pain, piloerection
- Neonates: seizure, death
- Complications with specific agents:
- Meperidine, tramadol: seizures
- Methadone: QT prolongation
Anesthetics
Lidocaine
- Mechanism: Na-channel blockade
- Types:
- Ester (one “i”): cocaine, procaine, benzocaine
- Amide (two “i”): lidocaine, bupivacaine
- Toxicity
- Dose: 4mg/kg, 7mg/kg with epinephrine
- CNS: perioral numbness, slurred speech, seizure
- CV: VT, VF, AV block
- Methemoglobinemia: methylene blue
- Treatment
- Seizure management
- Bicarbonate for dysrhythmia
- Intralipid
Anti-cholinergics
Sympathetic | Parasympathetic |
---|---|
Mydriasis | Miosis |
Bronchodilation | Bronchospasm/bronchorrhea |
Tachycardia | Bradycardia |
Urinary retention | Urinary incontinence |
Hyperglycemia | Salivation/lacrimation |
Diaphoresis | Increased GI motility |
- Examples
- Atropine
- Anti-histamine
- TCA
- Phenothiazines
- Jimson weed
- Symptoms
- Peripheral: mydriasis, anhidrosis, flushing, hyperthermia, ileus, dry mucous membranes, AUR
- Central: agitation (passive), delirium, coma, seizure
- Treatment
- Supportive
- Benzodiazepines
- Theoretically physostigmine
- Avoid in seizure, QRS-widening, reactive airway disease
- Possible diagnostic use
Drugs causing miosis (COPS)
- C: cholinergics
- O: opioids
- P: phenothiazines
- S: sedatives
Drugs causing QT-prolongation
- Examples:
- Phenothiazines
- Anti-arrhythmics
- Butyrophenones (ex. haloperidol)
- Macrolides
- Fluoroquinolones
- Methadone
- Ondansetron
- Atypical antipsychotics
- Treatment
- Magnesium sulfate 2g IV over 1min
- Overdrive pacing (transcutaneous, transvenous if not captured)
- Consider isoproterenol (pharmacologic overdrive)
Serotonin syndrome
- Cause: exposure to serotonergic agent(s)
- Symptoms: agitation, mydriasis, tremor/clonus in lower extremities, tachycardia, hyperthermia
- Management
- Supportive care (IVF, vasopressors)
- Cooling measures and paralysis for hyperthermia
- Benzodiazepines
- Cyproheptadine 12mg PO/NG
- Dexmedetomidine infusion
Anti-emetics
Phenothiazines
- Examples: compazine (prochlorperazine), phenergan (promethazine)
- MOA: DA-antagonist
- AE: sedation, dystonia, parkinsonism
- Toxicity: seizure, VT, hypotension (TCA-like)
5-HT3 antagonists
- Examples: zofran (ondansetron), granisetron
- Toxicity: QT-prolongation
Anti-hypertensives
Calcium channel blockers
- Toxicity: hypotension, bradycardia, AV blockade, hyperglycemia
- Management
- Atropine: 0.5mg IV q2-3min
- Glucagon: 5mg IV q10min x2 (with anti-emetic)
- IVF, vasopressors (norepinephrine, epinephrine)
- Calcium: 3g gluconate, 1-3g chloride
- High-dose insulin: 1 unit/kg, monitor hypoglycemia/hypokalemia
- Intralipid: 1.5mL/kg bolus then 0.25mL/kg/minute
- GI decontamination
- Pacing, IABP, ECMO
Beta blockers
- Toxicity: similar to CCB, hypoglycemia
- Management: similar to CCB, calcium ineffective
Digoxin (foxglove, oleander)
- MOA: inhibits Na/K ATPase, increases intracellular calcium (inotropic)
- Toxicity
- CV: bradycardia, hypotension
- ECG: bidirectional VT, PVC, scooped ST-segment
- CNS: agitation, psychosis
- Visual: yellow-green vision, halo
- Metabolic: hyperkalemia (acute), hypokalemia, hypomagnesemia
- Treatment
- GI decontamination
- Atropine
- Transcutaneous pacing (avoid transvenous, irritable myocardium)
- Digibind
- Avoid calcium
Clonidine
- Toxicity: bradycardia, hypotension, opioid mimic (miosis, lethargy, respiratory depression)
- Management: supportive care, stimulation for respiratory depression, atropine
Sodium-channel blockers
- Drugs
- TCA
- Diphenhydramine
- Procainamide
- Carbamazepine
- ECG
- QRS prolongation
- Prominent “R” in aVR
- RAD
- Treatment
- Sodium bicarbonate
Anti-hyperglycemics
Sulfonylurea
- Symptoms: recurrent severe hypoglycemia
- Management: octreotide 50-75mcg SQ/IM q6h
Other agents that cause hypoglycemia
- EtOH
- B-blocker
- Quinine
- Salicylate
Environmental
Carbon monoxide
- Source: combustion (gas heater, indoor barbeque)
- Toxicity
- General: influenza-like, multiple proximate affected individuals
- GI: abdominal pain, nausea
- CNS: headache, dizziness, confusion, ataxia, seizure
- CV: palpitations, arrhythmia, hypotension, MI
- Treatment
- T½: RA 6h, NRB 1h, 3atm 0.5h
- Hyperbaric: neuro deficit, syncope, pregnancy, CV toxicity
Cyanide
- Mechanism: inhibits oxidative phosphorylation
- Source: structural fire (wool, silk)
- Symptoms: syncope, seizure, coma, cardiovascular collapse
- Detection: severe lactic acidosis, “arterialization” of venous blood, “bitter almond” odor
- Treatment
- Hydroxycobalamin (Cyanokit): 5g IV, may repeat x1
- Sodium thiosulfate 12.5g IV
Methemoglobinemia
- Mechanism: Fe2+ converted to Fe3+, “functional anemia”
- Source: nitrite (food), topical/local anesthetics, pyridium, dapsone, reglan
- Detection: normal PaO2, SpO2 85% unresponsive to supplemental oxygen, ABG with co-oximetry
- Management: methylene blue 1-2mg/kg IV if symptomatic or MetHb >25%
- Contraindicated in G6PD deficiency, treat with exchange transfusion or HBO
Hydrogen Sulfide
- Source: industrial, sulfur spring, sewer
- Detection: “rotten egg” odor
- Management: remove from source, supportive care
Hydrocarbon
- Source: huffing canisters
- Toxicity: VT/VF from myocardial sensitization
- Management: beta-blockade
- Complications: harmless if ingested, aspiration leads to ARDS
Hydrofluoric acid
- Source: rust remover, wheel cleaner, glass etching
- Symptoms: pain-out-of-proportion, delayed onset
- Toxicity: Hypocalcemia (QTc prolongation, VT/VF/TdP), hyperkalemia, hypomagnesemia
- Management: analgesia, topical calcium gluconate gel, intravenous calcium for large BSA involvement
Alkaline ingestion
- Symptoms: esophageal perforation, delayed stricture
Acid ingestion
- Symptoms: gastric perforation (rare), delayed gastric outlet obstruction
- Findings: metabolic acidosis
Botulism
- Sources
- Adult: ingested preformed toxin
- Infants: ingested spores (achlorhydric), in vivo toxin production
- Wound: black tar heroin
- Symptoms: dysphagia, ptosis, diplopia, respiratory failure, descending paralysis
- Infants: constipation, floppy
- Management: supportive care, intubation
- Adults: Anti-toxin from CDC or local Department of Health
- Infants: 100mg/kg IV x 1 dose (BabyBIG)
Heavy Metals
Iron
- Dose
- Ferrous sulfate: 20% elemental iron
- Toxic: >20mg/kg
- Lethal: >60mg/kg (1 tablet 325mg ferrous sulfate per kilogram)
- Toxicity: corrosive, anti-coagulant, hepatotoxic
- Course
- Stage I: GI effects, emesis with hematemesis
- Stage II: Quiescent
- Stage III: Systemic, multi-organ system dysfunction
- Stage IV: Resolution, gastric scarring and outlet obstruction
- Workup
- CBC/BMP
- LFT
- Lactate
- Fe level
- KUB (if positive consider WBI)
- Treatment
- Decontamination: no activated charcoal, consider WBI
- Deferoxamine: 15mg/kg/hr
Lead
- Source: paint, batteries
- Toxicity
- Acute: headache, encephalopathy, seizure
- Chronic: malaise, weight loss, arthralgia, anemia (basophilic stippling)
- Diagnosis: lead level, wrist drop
- Management: chelation (BAL, EDTA, DMSA) for level >50ug/dL or asymptomatic >70ug/dL
Lithium
- Source: iatrogenic, drug-drug interaction
- Symptoms
- GI: nausea/vomiting, diarrhea
- CNS: tremor, coma
- CV: TWI, QT-prolongation
- Management
- IVF, encourage renal elimination
- Hemodialysis
Other Drugs
Disulfuram
- MOA: aldehyde dehydrogenase inhibitor
- Symptoms: increased acetaldehyde leads to flushing, headache, nausea/vomiting, tachycardia, hypotension
- Management: antihistamine, IVF, vasopressors
- Other agents causing disulfuram-like reaction: metronidazole, INH, sulfonylurea
Isoniazid
- Toxicity: seizure
- Management: pyridoxine 5g IV, repeat x1
Theophyline
- Toxicity: seizure
- Management
- Decontamination: AC
- Seizures: benzodiazepines
- Tachyarrhythmia (commonly MAT): beta-blockade
- Hemodialysis: acute > 100mg/L, chronic >30mg/L
Monoamine oxidase inhibitors
- Toxicity: food/drug interaction
- Symptoms: tachycardia, hypertension, hyperthermia, agitation
- Management: cooling, IVF, management of hyper/hypotension
Phenytoin
- Oral: cerebellar dysfunction (ataxia), CNS depression
- IV: hypotension (suspension contains propylene glycol)
Nutritional Supplements
- Fat-soluble vitamins
- A: benign intracranial hypertension
- D: hypercalcemia
Envenomations
Snake
- Crotalid (rattle), elapidae (coral)
- Symptoms
- Local reaction: edema, hemorrhagic bullae
- Systemic: perioral numbness, fasciculations
- Severe: thrombocytopenia, decreased fibrinogen
- Management: Crofab 5 vials
Spider
- Black widow
- Identification: hourglass on abdomen
- Symptoms: painful bite, target-appearance, rarely “acute abdomen”
- Management: analgesia, anti-venom, tetanus
- Brown recluse
- Identification: violin shape on head
- Geography: Southeast, Midwest
- Symptoms: painless bite, local reaction, delayed healing with eschar
- Rare: hemolysis, DIC, shock
- Management: supportive care, antibiotics if superinfected, consider dapsone, tetanus
Scorpion (Centruroides)
- Geography: Arizona
- Symptoms
- Autonomic: HTN, tachycardia, diaphoresis
- CNS: opsoclonus, slurred speech, dysphagia
- Management: anti-venom, supportive care, analgesia, tetanus
Marine
- Ciguatera
- Source: toxin bioconcentrated in fish
- Symptoms: gastroenteritis, hot/cold-reversal, “loose teeth” sensation
- Management: mannitol
- Scombroid
- Source: poorly-refrigerated fish, histamine-like
- Symptoms: flushing trunk/face (distinguish from allergic reaction), gastroenteritis
- Management: supportive care, IVF, anti-histamine, bronchodilators if indicated
- Paralytic shellfish poisoning
- Source: bivalve
- Symptoms: gastroenteritis, paralysis
- Management: supportive, intubation
- Jellyfish and Cnidaria
- Source: nematocyst
- Symptoms: burning pain, pruritus
- Severe: Irakundji syndrome (HTN, pulmonary edema)
- Management: supportive, analgesia, box jellyfish antidote, consider vinegar
- Stingray
- Source: heat-labile toxin
- Management: affected area in warm water, tetanus, ciprofloxacin (Vibrio)
Mushrooms
- Amanita: centrilobular necrosis, similar to acetaminophen
- Gyronatum: similar to INH (seizure and treatment), may cause methemoglobinemia
- Symptoms: muscarinic (SLUDGE)
- Early onset generally benign, delayed onset (>6h) suggests more serious course
- Management: atropine, glycopyrrolate, IVF
Pesticides
- Organophosphate: irreversible
- Carbamate: reversible
- Symptoms: muscarinic (SLUDGE)
- Treatment: atropine 2-6mg IV double q5min to control secretions, pralidoxime (for organophosphates)
Strychnine
- Source: rodenticide
- Symptoms: myoclonus, opisthotonus, agitation
- Management: benzodiazepines, airway protection, paralysis