- •Contents
- •1. Pharmacokinetics
- •3. Practice Questions
- •2. Antiarrhythmic Drugs
- •3. Antihypertensive Drugs
- •3. Anticonvulsants
- •5. Opioid Analgesics
- •8. Drugs of Abuse
- •1. Antibacterial Agents
- •4. Antiprotozoal Agents
- •1. Histamine and Antihistamines
- •3. Drugs Acting on Serotonergic Systems
- •1. Drugs Used in Diabetes
- •2. Steroid Hormones
- •6. Endocrine Drug List
- •1. Anticancer Drugs
- •1. Immunopharmacology
- •1. Toxicology
- •2. Toxicology Practice Questions
- •Index
Toxicology 1
COMMON TOXIC SYNDROMES
Table Xl-1-1. Signs, Symptoms, and Interventions or Antidotes for Common Toxic Syndromes
Compound(s) |
Signs and Symptoms |
Interventions and Antidotes |
AChE inhibitors |
Miosis, salivation, sweats, GI cramps, diarrhea, |
Respiratory support; atropine + pralidoxime (for |
|
muscle twitches seizures, coma, respiration |
irreversible AChE inhibitors) |
|
failure |
|
Atropine and |
i HR, i BP, hyperthermia (hot, dry skin), |
muscarinic |
delirium, hallucinations, mydriasis |
blockers |
|
Carbon monoxide |
Nausea and vomiting, dyspnea with |
(>10% carboxyHb) |
hyperventilation, mydriasis, vertigo; |
|
cardiovascular signs prominent, i BP, syncope, |
|
i HR, arrhythmias |
Control cardiovascular symptoms and hyperthermia + physostigmine (crosses blood brain barrier)
Hyperbaric 02 and decontamination (humidified 100% 02 okay in mild overdose)
CNS stimulants |
Anxiety/agitation, hyperthermia (warm, sweaty |
Control cardiovascular symptoms, hyperthermia, |
|
skin), mydriasis, i HR, i BP, psychosis, seizures |
and seizures- +/- BZs or antipsychotics |
Opioid analgesics |
Lethargy, sedation, i HR, i BP, hypoventilation, |
Ventilatory support; naloxone at frequent |
|
miosis, coma, respiration failure |
intervals |
Salicylates (ASA)* |
Confusion, lethargy, hyperventilation, |
Correct acidosis and electrolytes-urinary |
|
hyperthermia, dehydration, hypokalemia, |
alkalinization, possible hemodialysis |
|
acidosis, seizures, coma |
|
Sedative-hypnotics |
Disinhibition (initial), lethargy, ataxia, |
Ventilatory support-flumazenil if BZs implicated |
and ethanol |
nystagmus, stupor, coma, hypothermia, |
|
|
respiratory failure |
|
SSRls |
Agitation, confusion, hallucination, |
|
muscle rigidity, hyperthermia, i HR, i BP, |
|
seizures |
Control hyperthermia and seizures-possible use of cyproheptadine, antipsychotics, and BZs
Tricyclic |
Mydriasis, hyperthermia (hot, dry skin), 3 Cs |
Control seizures and hyperthermia, correct |
antidepressants |
(convulsions, coma, and cardiotoxicity) |
acidosis and possible arrhythmias |
|
arrhythmias |
|
*More details in antiinflammatory section
MEDICAL 309
Section XI • Toxicology
HEAVY METAL POISONING
Signs and symptoms are distinctive but usually result from inhibition of -SH groups on enzymes and regulatory proteins.
Table Xl-1-2. Signs, Symptoms, and Interventions or Antidotes for Heavy Metal Poisoning
Metals and Source
Arsenic (wood preservatives, pesticides, ant poisons)
Iron (medicinal for anemias and prenatal supplements)
Lead (tap water, leaded paint chips, herbal remedies, gas sniffing, glazed kitchenware, etc.)
Signs and Symptoms
Acute: gastroenteritis, hypotension, metabolic acidosis, garlic breath, "rice water" stools, torsades, seizures
Chronic: pallor, skin pigmentation (raindrop pattern), alopecia, stocking glove neuropathy, myelosuppression
Acute (mainly children): severe GI distress necrotizing gastroenteritis with hematemesis and bloody diarrhea, dyspnea, shock, coma
Acute: nausea and vomiting, GI distress and pain, malaise, tremor, tinnitus, paresthesias, encephalopathy (red or black feces)
Chronic: multisystem effects-anemia (t heme synthesis), neuropathy (wrist drop), nephropathy (proteinuria, failure), hepatitis, mental retardation (from pica), J, fertility and i stillbirths
Interventions and Antidotes
Activated charcoal, dimercaprol
Penicillamine or succimer
Gastric aspiration + carbonate lavage, deferoxamine IV
Decontamination-gastric lavage + dimercaprol (severe) or EDTA or succimer (penicittamine if unable to use dimercaprot or succimer)
Children: succimer PO
Mercury (elemental in instruments); salts used in amalgams, batteries, dyes, electroplating, fireworks, photography
Acute: vapor inhalation-chest pain, dyspnea, pneumonitis
Acute: inorganic salt ingestion-hemorrhagic gastroenteritis, acute tubular necrosis, shock
Chronic: organic Hg-CNS effects, ataxia, paresthesias, auditory and visual toss, loosening ofteeth
Succimer PO or dimercaprol (IM)
Activated charcoal for oral ingestion, then support with succimer PO or dimercaprot (not IV) causes redistribution of Hg to the CNS ineurotoxicity
310 MEDICAL
Chapter 1 • Toxicology
ANTIDOTES
Table Xl-1-3. Summary of Antidotes
Antidote |
Type of Poisoning |
Acetylcysteine |
Acetaminophen |
Atropine + pralidoxime |
AChE inhibitors-physostigmine, neostigmine, and |
(for irreversible AChE |
pyridostigmine; organophosphates, including |
inhibitors) |
insecticides, such as malathion and parathion |
Deferoxamine |
Iron and iron salts |
Digoxin immune F(ab) |
Digoxin |
Dimercaprol (BAL) |
Arsenic, gold, mercury, lead; oral succimer for milder |
|
lead and mercury toxicity |
EDTA |
Backup in lead poisoning, then for rarer toxicities |
|
(Cd, Cr, Co, Mn, Zn) |
Esmolol |
Theophylline, beta agonists |
Ethanol, fomepizole |
Methanol or ethylene glycol |
Flumazenil |
Benzodiazepines, zolpidem, zaleplon |
Naloxone |
Opioid analgesics |
Oxygen |
Carbon monoxide |
Penicillamine |
Copper (e.g., Wilson's disease), iron, lead, mercury |
Physostigmine |
Anticholinergics: atropine, antihistamine, |
|
antiparkinsonian-not tricyclics |
Protamine |
Heparins |
Vitamin K |
Warfarin and coumarin anticoagulants |
Activated charcoal |
Nonspecific: all oral poisonings except Fe, CN, Li, |
|
solvents, mineral acids, or corrosives |
MEDICAL 311
Chapter 1 • Toxicology
Table Xl-1-5. Purified Nutritional Supplements |
|
|
Name |
Pharmacology |
Side Effects |
Dehydroepiandrosterone |
Androgen precursor advocated |
Females: |
(DHEA) |
fortreatment ofAIDS Ci CD4 in |
androgenization |
|
females), Alzheimer disease |
and concern |
|
and "aging," diabetes, |
regarding CV |
|
hypercholesterolemia, and SLE |
disease and breast |
|
ct in symptoms and "flare |
cancer |
|
ups" in females) |
Males: |
|
|
|
|
|
feminization in |
|
|
young and concern |
|
|
in elderly regarding |
|
|
BPH and cancer |
Melatonin |
Serotonin metabolite used for |
Drowsiness, |
|
"jet-lag" and sleep disorders |
sedation, |
|
|
headache. |
Contraindicated in pregnancy, in women trying to conceive Ct LH), and in nursing mothers
Ct prolactin)
Chapter Summary
•Table Xl-1-1 lists the common toxic syndromes with their signs and symptoms and potential modes of intervention and/or antidotes.
•Table Xl-1-2 lists the common heavy metal poisons with their most common
sources, signs, and symptoms and potential modes of intervention and/or antidotes.
•Table Xl-1-3 lists antidotes and the type of poisoning against which they act.
•Table Xl-1-4 lists the characteristics of selected herbals, and Table Xl-1-5 lists the relevant purified nutritional supplements.
MEDICAL 313