Focus on Pharmacology Essentials for Health Professionals

Copyright ©2008 by Pearson Education, Inc.Upper Saddle River, New Jersey 07458

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Focus on Pharmacology, First EditionBy Jahangir Moini

Focus on PharmacologyEssentials for Health

Professionals

Chapter 28Toxicology

Jahangir Moini, MD, MPH




Toxicology

• 10 million people are poisoned in U.S. each year

• Attempted suicide

• Accidental legal drug overdosage

• Illegal drug overdosage

• Snake, spider bites

• Exposure to toxins in workplace




Prevention

• Child-resistant packaging

• Poison Control Centers

• Medication error prevention

• Safe storage of toxins in home




Poison Detection

• Some poisons have specific symptoms to assist in giving an accurate diagnosis:– Cyanide: unmistakable odor of bitter

almonds– Insecticides: GI hyperactivity, salivation,

pupillary constriction– Carbon monoxide: cherry-colored flush of

skin and mucous membranes




Treatment of Poisoning

• Emetics: (e.g., ipecac): trigger vomiting; contraindicated in ingestion of corrosives

• Absorbents: (activated charcoal): bind poison molecules to charcoal and excreted; effective in heavy metal and corrosive chemical poisoning




Specific Poisons: Acetaminophen

• Acetaminophen (Tylenol): nausea and vomiting (early stages); liver injury after 2–3 days

• Antidote: acetylcysteine given within 8–10 hours




Specific Poisons: Alcohols

• Ethanol or ethyl alcohol

• Treatment includes:– Emesis, gastric lavage– Hemodialysis




Specific Poisons: Ethylene Glycol• Antifreeze, windshield de-icing solutions• Signs/symptoms: within 1–12 hours:

nausea, vomiting, seizures, cerebral edema, coma, death; 12–14 hours: tachypnea, cyanosis, tachycardia, pulmonary edema, pneumonitis

• Treatment: gastric lavage within 30 minutes; 10% solution of ethanol; and hemodialysis




Specific Poison:Heparin and Warfarin

• Heparin signs/symptoms: hemorrhage, ecchymoses, melena

• Heparin treatment: slow IV infusion of protamine sulfate

• Warfarin signs/symptoms: hemorrhage• Warfarin treatment: phytonadione

(vitamin K); blood products with clotting factors




Specific Poison: Antihistamines

• Signs/symptoms: CNS excitement or depression; drowsiness, stupor, coma

• Supportive treatment; phenobarbital or diazepam to control convulsions




Specific Poison: Benzodiazepines

• Signs/symptoms: CNS depressants occur within 30 minutes; coma, respiratory depression

• Treatment: activated charcoal, respiratory support




Specific Poison: Bleaches

• Signs/symptoms: corrosive action in mouth, pharynx, esophagus

• Treatment: dilute ingested bleach with milk or water




Specific Poison:Carbon Monoxide

• Signs/symptoms: cherry color in skin and mucous membranes, coma, death

• Treatment: pure oxygen, ventilation support, diuretics and steroids (to treat resultant cerebral edema)




Specific Poison: Corrosives

• Ingestion almost always with suicidal intent

• Signs/symptoms: irritation, severe pain, bleeding, severe burns in mouth, esophagus, stomach; profound shock

• Treatment: immediate dilution with water or milk; emesis or gastric lavage contraindicated




• Signs/symptoms: tremor, diarrhea, polydipsia, anorexia, polyuria, vomiting, blurred vision, hypothyroidism, hyperglycemia, weight gain

• Treatment: gastric lavage within 1 hour; activated charcoal, whole bowel irrigation

Specific Poison: Lithium




Specific Poison: Mercury

• Signs/symptoms: burning sensation in throat, metallic taste, discoloration and edema of mouth, vomiting, bloody diarrhea, shock

• Treatment: gastric lavage, activated charcoal




Specific Poison: Opioids

• Signs/symptoms: euphoria, drowsiness, constricted pupils, hypotension, bradycardia, hypothermia, coma, respiratory arrest

• Treatment: gastric lavage or emesis, activated charcoal




Bites and Stings

• Scorpion: treatment is antivenom, calcium gluconate, and phenobarbital

• Spiders: antivenom, IV calcium gluconate, antibiotics, tetanus immunization, oxygen, antihistamines, adrenalin, muscle relaxants

• Snake bites: reducevenom absorption; incision and suction; ice should not be applied to bite

Focus on Pharmacology Essentials for Health Professionals

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