ABP Med Toxicology key terms

The ratio between a drug's toxic dose and its effective dose; a narrow index means the gap between helpful and harmful amounts is small, so minor dosing errors can cause serious poisoning.

A recognizable cluster of physical signs, such as pupil size, skin moisture, bowel sounds, and mental status, that points to a particular class of poison and guides early treatment before laboratory results return.

The single dose of a substance expected to kill half of an exposed test population under stated conditions; it allows rough comparison of toxicity between agents but does not predict an individual patient's outcome.

A calculated volume relating the total amount of drug in the body to its measured plasma concentration; large values suggest extensive tissue binding and make dialysis or urinary elimination less effective.

Elimination at a constant rate regardless of concentration because metabolic enzymes are saturated; small additional doses then produce disproportionately large and prolonged rises in blood level.

The difference between measured cations and anions in serum, calculated as sodium minus chloride and bicarbonate; a raised gap suggests accumulation of unmeasured acids such as salicylate, methanol, or formate.

The difference between measured osmolality and calculated osmolality; an elevated gap suggests an unmeasured osmotically active substance such as methanol, ethylene glycol, or isopropanol is present in the blood.

A large family of liver enzymes that oxidize drugs and toxins; individual variation and co-ingested inhibitors or inducers change how quickly a poison is activated or cleared from the body.

The syndrome of aspirin toxicity, with tinnitus, vomiting, sweating, rapid breathing, and a mixed acid-base disturbance that can progress to seizures, coma, and pulmonary edema in severe overdose.

A reactive metabolite formed when acetaminophen is oxidized by cytochrome P450; it is normally detoxified by glutathione, and when glutathione stores are depleted it injures liver cells.

Poisoning by cardiac glycosides causing nausea, visual color disturbances, confusion, bradyarrhythmias, and hyperkalemia; management includes correcting potassium and giving digoxin-specific antibody fragments.

Blockade of fast cardiac sodium channels by drugs such as tricyclic antidepressants, widening the QRS complex and causing hypotension and ventricular arrhythmia; sodium bicarbonate is the main antidote.

A condition in which oxidized iron in hemoglobin cannot carry oxygen, producing cyanosis unresponsive to supplemental oxygen, chocolate-colored blood, and a low measured saturation despite normal oxygen pressure.

Overdose causing bradycardia, hypotension, hypoglycemia, and conduction block; high-dose insulin with glucose, glucagon, and vasopressors support the circulation when fluids and atropine fail.

A self-limited syndrome after stopping or reducing opioids, with yawning, runny nose, tearing, gooseflesh, abdominal cramps, diarrhea, and agitation; it is extremely unpleasant but rarely life-threatening.

Severe alcohol withdrawal with clouded consciousness, hallucinations, tremor, and autonomic overactivity, appearing days after the last drink and carrying substantial risk of death without adequate sedation.

Excess adrenergic signaling from cocaine, amphetamines, or similar agents, producing agitation, dilated pupils, sweating, fast heart rate, high blood pressure, and dangerously elevated body temperature.

A triad of mental status change, autonomic hyperactivity, and neuromuscular findings such as clonus and hyperreflexia, caused by serotonergic drugs; treatment is stopping the drug, sedation, and supportive care.

Inhalation of an odorless gas that binds hemoglobin and blocks oxygen delivery, causing headache, dizziness, syncope, and delayed neurological injury; treatment is high-flow oxygen and hyperbaric therapy in selected cases.

Swallowing strong acid or alkali that produces deep chemical burns of the mouth, esophagus, and stomach; management avoids emetics and charcoal, and early endoscopy grades the severity of injury.

Lung injury after petroleum distillates enter the airways, causing cough, hypoxia, and chemical pneumonitis; gastric emptying and charcoal are avoided because they increase vomiting and the risk of aspiration.

Insecticides that inhibit acetylcholinesterase so acetylcholine accumulates at nerve endings; poisoning presents with cholinergic signs and is treated with atropine plus an oxime given early.

The pattern of excess acetylcholine, with salivation, lacrimation, urination, diarrhea, vomiting, bronchorrhea, bradycardia, small pupils, and muscle weakness, seen with organophosphates and carbamates.

Toxicity causing abdominal colic, anemia, peripheral neuropathy, hypertension, and in children developmental delay; diagnosis relies on blood lead level, and severe cases require chelation therapy.

An organic mercury form that concentrates in fish and is well absorbed from the gut, causing numbness, ataxia, visual field loss, and fetal brain damage from maternal exposure.

A heat-stable toxin in certain Amanita mushrooms that shuts down RNA transcription in the liver, causing delayed vomiting and diarrhea followed by hepatic failure; supportive care and antidote attempts are urgent.

A potent sodium channel blocker found in pufferfish and some other marine animals; it causes numbness, weakness, and paralysis while consciousness is preserved, and care is largely supportive.

Blockade of muscarinic receptors producing dry skin, flushed face, dilated pupils, urinary retention, absent bowel sounds, and delirium, often remembered as blind as a bat and mad as a hatter.

A pit viper bite causing local tissue damage, coagulopathy, low platelets, and systemic bleeding; treatment is antivenom guided by worsening local findings and laboratory abnormalities.

A glutathione precursor and antioxidant used for acetaminophen overdose; it replenishes glutathione, detoxifies the reactive metabolite, and works best when started soon after ingestion.

A competitive opioid receptor antagonist that rapidly reverses respiratory depression from opioids; repeated doses or a continuous infusion may be needed because its effect is shorter than many opioids.

A fine black powder that adsorbs many drugs and chemicals within the gut, reducing absorption when given soon after ingestion; it is avoided for caustics, hydrocarbons, and unprotected airways.

Intravenous fat emulsion given as rescue treatment for severe local anesthetic systemic toxicity and refractory cardiotoxic overdose, thought to work as a lipid sink and as a metabolic fuel for the heart.

A drug that blocks alcohol dehydrogenase, preventing formation of toxic metabolites from methanol and ethylene glycol; it is given early, with hemodialysis added for severe poisoning.

A cobalt-containing form of vitamin B12 that binds cyanide to form cyanocobalamin, used for suspected smoke-inhalation cyanide poisoning; it can discolor skin, urine, and colorimetric laboratory tests.

Swallowing a small disc battery that generates hydroxide at its negative pole, causing rapid transmural esophageal burns; it is a time-critical emergency requiring urgent endoscopic removal.

Ingestion of ferrous salts causing vomiting, bloody diarrhea, metabolic acidosis, shock, and liver injury, with a latent phase that can falsely suggest recovery; deferoxamine is the antidote.

High-dose insulin with supplemental glucose used for severe calcium channel blocker or beta blocker poisoning, improving cardiac contractility without relying on adrenergic receptors.

Breakdown of skeletal muscle releasing myoglobin and potassium into the blood, causing dark urine, acute kidney injury, and arrhythmia; treatment is aggressive fluid resuscitation with close electrolyte monitoring.

Cardiopulmonary bypass support that oxygenates and circulates blood outside the body, used for poisoned patients with refractory shock or cardiac arrest when antidotes and standard resuscitation have failed.