Medical Archive

Chapter 176: General Management of Poisoned Patients 

# ?? ?? ?? drug intoxication

• ???? ??? ?? ??
• ??
• ?? ?? ?? ??? ??
• ????

Chapter 177: Cyclic Antidepressants 

TCA overdose

• Anticholinergic (M)
  • Hyperthermia, tachycardia, dilated pupils, skin flushing, intestinal ileus, urinary retention, dry mouth
  • Tertiary > Secondary
  • Confusion, hallucination in the elderly
• Antihistamine (H1)
  • ???, ??
• ?1-blocking effect
  • Hypotension – can be refractory to management and is the major cause of mortality in TCA overdose.
• Presynaptic (NE & 5-HT) neurotransmitter reuptake
  • Antidepressant & anxiolytic effects, seizures, tremors
• Blockade of cardiac fast Na+ channels 
  • Prolonged PR/QT interval, arrhythmias (eg, ventricular tachycardia, fibrillation)
  • Widened QRS interval (like Ic group)
• Convulsion, Coma

Management of intoxication

• Supplemental O2, intubation, IV fluids
• Activated charcoal for patients within 2 hours of ingestion (unless ileus present)
• IV NaHCO3 for arrhythmia
  • Indication: QRS interval >100 msec.
  • ?Extracellular Na concentration
  • ?Serum pH, which favors the non-ionized(neutral) form fo the drug, making it less accessible to bind to sodium channels.

Chapter 178: Atypical and Serotonergic Antidepressants 

Chapter 179: Monoamine Oxidase Inhibitors 

Chapter 180: Antipsychotics 

Chapter 181: Lithium 

Chapter 182: Barbiturates 

Chapter 183: Benzodiazepines 

Flumazenil.
??? ??? ?? ????? ?? ???.

Chapter 184: Nonbenzodiazepine Sedatives 

Chapter 185: Alcohols 

Chapter 186: Opioids 

Chapter 187: Cocaine and Amphetamines 

Chapter 188: Hallucinogens 

Chapter 189: Salicylates 

Acute intoxication

• ??: respiratory alkalosis
  • Salicylates directly stimulate the medullary respiratory center
  • Increased ventilation and loss of CO2
• ??: AGMA starts several hours later
  • Salicylates ?lipolysis, uncouple oxidative phosphorylation, ?citric acid cycle
  • PaCO2 will be lower than predicted respiratory compensation d/t concurrent primary respiratory alkalosis.

Chronic intoxication

• In young children and elderly.
• Management
  • IV sodium bicarbonate therapy
    • To increase salicylate (anion) excretion
    • However, large volumes are required.
  • Hemodialysis
    • Those who cannot tolerate the large volumes of bicarbonate required, such as those with renal failure, ESRD, salicylate-induced pulmonary edema.

Chapter 190: Acetaminophen 

• Pathology
  • ??? CYP450??? glutathione? ????? NAPQI??
  • Glutathione ??? 30% ???? ???
• High risk
  • glutathione? ???? (alcoholics, AIDS ??, ??)
  • cytochrome P-450? ???? (alcoholics, ????/???? ??)

Evaluation

???? ?? ??? 500mg. 10g?? 20?!

>10 g or 200 mg/kg	single
>10 g or 200 mg/kg	Over 24hr
>6g or 150mg/kg	?? ??

Acetaminphen ???? ??, ??? 2?? ?? ??
4hr APAP ?? ?? (?g/dL) ?? ??? ???

<150	1% ?
>200	60%
>300	90%

Management

• NAC (N-acetylcystein)
  • APAP ?? ? 8hr ???
  • ??, ?? ?????? PT monitoring
• ?? ??? 2-3? ?? stage 2 (??, ??? ??)?? ??? ?? ??

Chapter 191: Nonsteroidal Anti-Inflammatory Drugs 

Chapter 192: Methylxanthines and Nicotine 

Chapter 193: Digitalis Glycosides 

Chapter 194: Beta-Blockers 

Clinical features

• Symptom onset: 2-6 hours after ingestion
• Cardiogenic shock
  • Hypotension, bradycardia
• Bronchospasm
• Hypoglycemia
• Altered mental status, seizures

Treatment

• Airway management
• IV glucagon
  • ? intracellular cAMP via Gs
  • 2nd line: atropine, isoproterenol
• IV calcium
• Catecholamine vasopressors (epinephrine or norepinephrine)
• High-dose insulin and glucose
• IV lipid emulsion therapy
  • Used to manage poisoning in lipophilic medications such as beta blockers.

Chapter 195: Calcium Channel Blockers 

Chapter 196: Antihypertensives 

Chapter 197: Anticonvulsants 

Chapter 198: Iron 

Chapter 199: Hydrocarbons and Volatile Substances 

Chapter 200: Caustic Ingestions 

Acid – coagulation necrosis
Alkaline – liquefactive necrosis

Clinical features

Chemical burn or liquefaction necrosis resulting in:
Laryngeal damage: hoarseness, stridor
Esophageal damage: dysphagia, odynophagia
Gastric damage: epigastric pain, bleeding

Management

• Secure airway, breathing, circulation
• Decontamination
  • Remove contaminated clothing & visible chemicals
  • Irrigate exposed skin
• Chest x-ray
  • If respiratory symptoms.
  • To identify any signs of perforation.
• Consider gastric lavage if NG tube is placed
• Do not perform
  • Activated charcoal
    • Caustic ingestions cause immediate local damage.
    • Would obstruct the view during endoscopy
  • Inducing vomiting with ipecac

Inpatient

• Endoscopy within 12-24hr if hemodynamically stable & without respiratory distress or perforation
  • To assess the severity of esophageal damage
• Serial x-rays to r/o perforation
• Tube feedings & surgical intervention for severe injury

Complications

• Upper airway compromise
• Perforation
• Stricture/stenosis (2-3 weeks)
• Ulcers
• Cancer

Chapter 201: Pesticides 

Management

1. Patient stabilization (ie, airway, breathing, circulation)
2. Decontamination
   • Removal of exposed clothes
   • Copious irrigation of the skin and/or eyes
3. Atropine
   • Reverses muscarinic symptoms
   • ????, ??? ??
4. Pralidoxime (2-PAM)
   • Reverses nicotinic symptoms
   • ?? ??, ? ?? ?? ??

Chapter 202: Anticholinergics 

Chapter 203: Metals and Metalloids 

Chapter 204: Industrial Toxins 

# Cyanide

Amyl nitrite – ??
Sodium nitrite – ??

C450 Poisoning and Drug Overdose

# Nitrite

Methylene blue
?? ?? ?? ??

Chapter 205: Vitamins and Herbals 

Chapter 206: Antimicrobials 

Chapter 207: Dyshemoglobinemias