Chapter 27. Toxicology

• There are approximately 2.4 million cases of ingestion or toxin exposure annually in the US. Half are in children younger than 6 yr, with a peak incidence at age 1–2 yr. Two-thirds are in patients younger than age 20 yr.
• Leading fatal agents of ingestion (all ages): Analgesics, antidepressants, cardiovascular drugs, street drugs.
• Leading agents of ingestion (adolescents): Acetaminophen, barbiturates, stimulants, antidepressants, alcohol.
• Majority of poisonings occur at home, and ∼10% involve two or more substances.
• Adolescents: 50% intentional; 50% unintentional.
• Poisonous substance storage precautions should be discussed at every 6-month well-child visit.
• Child-resistant closures have decreased the mortality of unintentional ingestions by 45%.
• One to two tablets or 1 to 2 tsp (standard pediatric “swallow” ∼5–10 cc) of the standard-strength preparations of the following medications are potentially fatal to a 10-kg child:
  • Antiarrhythmics, antimalarials (chloroquine, hydroxychloroquine), benzocaine, β-blockers, CCBs, camphor, clonidine, Lomotil (diphenoxylate/atropine), lindane, methyl salicylate, opioids (codeine, morphine, pentazocine), phenothiazines (thioridazine, chlorpromazine), quinine, theophylline, TCAs (imipramine, desipramine)
• Nontoxic pharmaceuticals: Antacids, antibiotics, corticosteroids, contraceptives, laxatives, mineral oil, ACE inhibitors
• Nontoxic household products: Cosmetics, deodorants, dehumidifying (silica gel) packets, matches, candles

(Emerg Med Clin North Am 2007;25:249)

• History Should address the questions what?, when?, how?, how much?, what symptoms?, and why?: Timing of ingestion, substance(s) taken, amount taken (pill count or volume quantification, if bottle available), location of ingestion (kitchen vs bedroom vs other), reason or circumstances of exposure or ingestion, symptoms before arrival, other substances in the home (possible co-ingestions), concomitant illness or trauma (possible supratherapeutic or chronic dosing of acetaminophen or aspirin), history of depression or prior suicide attempts (in adolescents), history of street drug use.

• Anticipate: Seizures, altered mental status, multi-organ dysfunction, respiratory failure, cardiac failure, arrhythmias, or unexplained metabolic ...