Toxicology Flashcards
What I is the most important aspect in treating intoxications
Patients with depressed mental status should receive what treatment?
Supportive management is the most important aspect of treating most intoxications, although specific antidotes should be considered when indicated.
• Patients with depressed mental status should all receive empiric therapy with oxygen, dextrose, thiamine, and naloxone while evaluation is ongoin
Initial support measures require attention to the “ABCs” (airway, breathing, circulation).
• Administer a combination of thiamine 100 mg IV, dextrose 50 g IV, and naloxone (initial dose of 0.2–04 mg IV) to patients who present with change in mental status.
A toxidrome is a cluster of syndromes for a particular patient
You ought to wear protective gloves or decontaminate
How do you do this?
Decontaminate skin by removal of toxin with soap and water. Remove contaminated clothing and store in adequate container to limit ongoing exposure to patient and health care providers.
• Ocular decontamination may require prolonged irrigation with normal saline solution.
What is gastric emptying and how is it done
• Large-bore (Ewald) tubes 37–40 F may be needed to remove gastric debris.
Technique: Inspect mouth and clear off foreign material. Have suctioning equipment ready. Insert tube and confirm placement. Immediately withdraw as much of the gastric contents as possible. Instill 200 mL bolus of warmed water and aspirate gastric contents.
Repeat until gastric aspirate is clear.
State five contraindications of gastric emptying
Obtunded, comatose, or convulsing patients. Also ingestion of sustained-release or enteric-coated tablets and probably caustic liquids to avoid aspiration-induced lung injury.
This method of tube placement should not be used in patients with depressed level of consciousness unless intubation has been performed, since retching and vomiting is common.
What is active charcoal
In what cases is activated charcoal not effective
What are the contraindications of activated charcoal
Activated charcoal is a nontoxic, inert, nonspecific adsorbent that binds intraluminal drugs and decreases systemic absorption.
1 g/kg/every 4 Hour. for at least 3 doses.
It is not effective in iron,lithium,petrochemicals and kerosene poisoning
Contraindications: Patients unable to protect airway or during seizures.
When is whole bowel irrigation done and state four contraindications
May be particularly effective in cases of ingestion of sustained-release tablets, drugs where activated charcoal is not effective (iron, lithium)
• Contraindications: ileus, GI hemorrhage, bowel perforation.
State three uses of hemodialysis
Effective for removal of certain toxins and drugs (low molecular weight, water soluble, low protein binding, and small volume of distribution).
Early use of hemodialysis (HD) is recommended for intoxication with methanol, ethylene glycol, boric acid, salicylates, and lithium.
• Effective for use in heavy metal intoxication in patients with renal failure.
State three uses of hemoperfusion
Which things is it less effective for
Blood is pumped through an adsorbent system (usually a charcoal canister).
Has been effectively used for intoxications with theophylline, phenobarbital, phenytoin, carbamazepine, paraquat, and glutethimide.
• Less effective for lithium, ethanol, methanol, CO, cocaine, and phencyclidine.
How does hemofiltration work
Utilizes a highly porous membrane to remove drugs and toxins by convection.
• Potentially useful for removal of toxins that have a large volume of distribution, slow intracompartmental transfer, or extensive tissue binding.
• Specific hemofiltration cartridges can be used to effectively remove digoxin-Fab complexes, deferoxamine-iron complexes, and aluminum.
What is the toxic dose of acetaminophen or para
Acetaminophen is a ubiquitous analgesic-antipyretic agent that is included in over 600 commercial drug preparations.
It is also a hepatotoxin, and is the leading cause of toxic drug ingestion and acute liver failure in the United States.
toxic dose 7.5–15 grams
or 6-12grams
6g is 12 tablets of 500mg acetaminophen
What are the four stages of acetaminophen toxicity and what is the duration for each stage
What is the most sensitive marker of acetaminophen toxicity
The period following acetaminophen overdose is divided into four stages of toxicity.
In the initial stage (the first 24 hours), symptoms are either absent or non-specific (e.g., nausea), and no laboratory evidence of hepatic injury exists.
Second stage (24–72 hours after drug ingestion) occurs where clinical manifestations continue to be minimal or absent, but laboratory evidence of hepatic injury begins to appear. Elevated aspartate aminotranferase (AST) is the most sensitive marker of acetaminophen toxicity; the rise of AST precedes the hepatic dysfunction.
Third stage72–96 hours. In advanced cases of hepatic injury.
Four stage (after 72–96 hours) that is characterized by clinical and laboratory evidence of progressive hepatic injury and hepatic insufficiency (e.g., encephalopathy, oagulopathy) occasionally combined with renal insufficiency. Death from hepatic injury usually occurs within 3 to 5 days. Patients who survive often recover completely, although recovery can be prolonged.
What is the antidote for para
If this common antidote isn’t there, what else can you give?
IV N acetyl cysteine
Oral methionine
What occurs in benzodiazepine toxicity
Clinical Toxicity: Benzodiazepines produce a dose-dependent depression in the level of consciousness, but there is usually no respiratory or cardiovascular depression. However, there are several factors that predispose to respiratory and cardiovascular depression from benzodiazepines. These include advanced age of the patients, combined therapy with opioid analgesics, and drug accumulation from prolonged drug therapy.
What is the antidote for benzodiazepine toxicity
Flumazenil
Flumazenil is a benzodiazepine antagonist that binds to benzodiazepine receptors in the central nervous system.
Flumazenil is given as an intravenous bolus.
State ten signs and symptoms of beta blocker toxicity
It may take 24 hours before you see effect of beta blocker and calcium channel blocker overdose. Don’t be in a rush to discharge
Competitive antagonists of beta-receptors found in the heart (β1) and bronchial tree (β2).
Signs and symptoms of toxicity : Include hypotension, bradycardia, atrioventricular blocks, and congestive heart failure (CHF) with or without pulmonary edema.
Other effects include bronchospasm, hypoglycemia, hyperkalemia, lethargy, stupor, coma, and seizures.