Toxicology & Antidotes
A 5-year-old child who consumed nine tablets of amitriptyline 25 mg is transported to the hospital. She is awake with no apparent symptoms. How long after the ingestion does the medical team have to administer activated charcoal and have it be effective? Answer A 3 hours B 30 minutes C Activated charcoal is not indicated D 2 hours E 1 hour
e Activated charcoal is effective if administered within one hour of ingestion of a toxic substance; it adsorbs the drug and prevents it from absorbing into the body.
A 30-year-old male went out for his birthday last night. He consumed over 15 alcoholic beverages and now presents to the Emergency Department with presumed alcohol poisoning. What laboratory abnormality would likely be present? Answer ALeukocytosis BElevated hemoglobin CDecreased triglycerides DIncreased albumin EIncreased anion gap
e Alcohols (e.g., ethanol, methanol, propylene glycol) can result in an elevated anion gap.
Select the mechanism of action for atropine: Answer AAtropine is a beta-adrenergic agonist at the beta-2 receptors. BAtropine blocks acetylcholine at the muscarinic acetylcholine receptor. CAtropine is a beta-adrenergic agonist at both the beta-1 and beta-2 receptors. DAtropine is a mu-receptor antagonist. EAtropine is a cholinergic (acetylcholine) agonist.
bBy blocking acetylcholine, atropine is effective at treating "cholinergic" symptoms from organophosphate poisoning or other cholinergic drugs (in cholinergic overdoses, acetylcholine is increased).
JB is positive for tuberculosis and has been prescribed a regimen of rifampin, isoniazid, pyrazinamide and ethambutol for 8 weeks. She presents to the emergency room with seizures related to acute ingestion of an unknown amount of isoniazid. Which one of the following medications would be the most appropriate to administer? Answer A Cyanocobalamin (vitamin B12) B Pyridoxine (vitamin B6) CPhenazopyridine D Atropine E Deferoxamine
bPyridoxine (vitamin B6), in higher intravenous doses, is used to treat isoniazid-induced toxicity. It is taken daily in the oral form to prevent isoniazid-induced neuropathic damage.
Which of the following is a contraindication to activated charcoal use? Answer APresence of an NG tube BHistory of GERD CAn unprotected airway DCarbamazepine overdose EBeing an hour post-ingestion
c Activated charcoal should only be given if the airway is protected (i.e., the patient is awake and can clear their throat). If sedated or obtunded, there is a risk of aspiration. Aspiration of activated charcoal can cause damage to the lungs, and in severe cases, death. If used, it works best if administered within an hour of ingestion.
Which of the following drugs is an antidote for Xarelto? Answer APhytonadione BProtamine CAndexxa DDeferoxamine EPraxbind
c Andexanet alfa (Andexxa) is approved as a reversal agent for the Xa-inhibitors apixaban and rivaroxaban.
A man was bitten by a rattlesnake. What antidote can be provided? Answer ANeostigmine BSugammedex CCroFab DRabies vaccine EDimercaprol
c CroFab is crotalidae polyvalent immune antibody; it is used for copperhead and rattlesnake bites.
Which antidote is most appropriate for digoxin toxicity? Answer AFomepizole BGlucagon CDigiFab DDimercaprol ECyanokit
c DigiFab is digoxin immune antibody; it binds digoxin.
LC is a 55-year-old Hispanic female with renal insufficiency who has been hospitalized for acute decompensated heart failure. She was started on nitroprusside and is now experiencing nausea, confusion, rapid breathing and tachycardia. The physician suspects cyanide toxicity. What antidote should the pharmacist recommend? Answer AFomepizole B Atropine CHydroxocobalamin D Desferal EPralidoxime
c Hydroxocobalamin (Cyanokit) and sodium thiosulfate + sodium nitrate (Nithiodote) are antidotes for cyanide toxicity. The use of nitroprusside can result in cyanide toxicity, especially if the patient has renal insufficiency or if it is used for an extended duration.
A patient who is newly diagnosed with type 1 diabetes presents to his primary care physician with dizziness, weakness and hunger. His finger stick blood glucose reading in the office is 49 mg/dL. While in the examination room, the patient passes out. The best recommendation for this patient is: Answer A Insulin B Glucose tablets C Glucagon D Octreotide E Epinephrine
c Hypoglycemia in an unconscious patient (a patient who has "passed out") should be treated with dextrose injection or glucagon. Octreotide can be used specifically for sulfonylurea-induced hypoglycemia.
A patient is using dabigatran for stroke prevention in atrial fibrillation. Which drug would reverse the effects of dabigatran if the patient experiences serious bleeding? Answer AArgatroban BProtamine CIdarucizumab DVitamin K EAndexanet Alfa
c Idarucizumab (Praxbind) is a reversal agent specific for dabigatran (Pradaxa). Note the similarities in brand names.
A homeless man is admitted to the emergency room with pinpoint pupils, blue lips and shallow breathing. He is unresponsive to verbal commands. Which of the following treatments is recommended? Answer AAtropine BBuprenorphine CNaloxone DFlumazenil EMethylnaltrexone
c Naloxone (Narcan) should be administered if an opioid overdose is suspected (there are no adverse effects if naloxone is administered to a patient who did not ingest opioids).
Which of the following is/are different types of child-resistant (C-R) containers? (Select ALL that apply.) Answer AMonthly pillboxes B Flip caps C Card adherence packaging D Screw caps that require the user to press down while turning E Unit-dose packaging
cde Common C-R packaging is designed to prevent accidental poisoning in children. Methods include screw caps that require more than a simple turn to open, unit-dose packaging, card adherence and safety packaging that require the user to press on one side while pulling the medication card out of the other side. Tylenol, aspirin, ibuprofen, oxymetazoline and Benadryl are OTC products that require C-R packaging.
Glucagon can be used as an antidote for overdoses of which of the following? (Select ALL that apply.) Answer ADigoxin BLocal anesthetics COral hypoglycemics DBeta-blockers EInsulin
cde Glucagon can be used for the treatment of overdoses from beta-blockers, oral hypoglycemics and insulin.
A parent asks the pharmacist for quick advice: her child has sprayed a household chemical in his eye and it is burning. What should the pharmacist recommend? Answer ARemove contact lenses and sit with the eyes closed for one hour. BDo not do anything; take him to the emergency department. CNeutralize the chemical using a weak solution made with water and dishwashing soap. DRinse the eye gently with water from a tap or hose for at least 15 minutes. EPut the child in the shower and run water from the head to the toes for 10 minutes.
d Any chemical exposure to the eye should be evaluated. Poison control can be called for further advice at the toll-free number.
A 19-year-old college student arrives to the emergency room extremely agitated and restless. He states he took "a lot more" of his ADHD medication, Adderall, than was prescribed. Upon examination, he is tachycardic, hypertensive and has dilated pupils. Along with supportive care, which of the following medications can be administered? Answer AGlucagon BLeucovorin CSodium bicarbonate DLorazepam EDextrose
d Benzodiazepines may be administered for stimulant overdose (e.g., cocaine, amphetamines, weight-loss drugs, caffeine), especially to treat agitation and/or seizures.
A patient comes to the emergency department with a diltiazem overdose. Which of the following is an appropriate antidote to give to this patient? Answer ASodium bicarbonate BPhysostigmine CIpecac syrup DCalcium chloride EAlbuterol
d Calcium chloride or calcium glucagon, given IV, is the antidote for a calcium channel blocker overdose. ECG monitoring should occur.
A patient comes to the emergency department with respiratory depression and significant sedation. Paramedics found her down in her apartment with an empty bottle of Ativan on the floor. Which of the following is the appropriate antidote to give? Answer AIpecac syrup BSodium bicarbonate CDimercaprol DFlumazenil ESodium polystyrene sulfonate
d Flumazenil is the antidote for benzodiazepines (Ativan is lorazepam). Flumazenil can precipitate seizures when used in benzodiazepine-dependent patients.
Which of the following is contraindicated in a patient with G6PD deficiency? Answer AN-acteylcysteine BLeucovorin CPyridoxine DMethylene blue EDeferoxamine
d Methylene blue is the antidote for methemoglobinemia. It is contraindicated in patients with G6PD deficiency.
An obtunded teenager with a possible overdose is brought into the emergency department by EMS. The time of ingestion is unknown. The electrocardiogram shows widening of the QRS complex. Which of the following is the most appropriate treatment? Answer ALevocarnitine BSugammadex CMethylene blue DSodium bicarbonate EActivated charcoal
d The teenager's mental status and widened QRS complex are concerning for a TCA overdose. Sodium bicarbonate is an appropriate treatment for a widened QRS complex from a TCA overdose. Activated charcoal should not be given because he is obtunded and would be at risk for aspiration.
What is the antidote for iron overdose? Answer APralidoxime BNaloxone CMethylene blue DDeferoxamine ESodium bicarbonate
dIron overdoses are common in children and can cause serious toxicities, including severe organ damage. To reduce accidental poisoning, child-resistant (C-R) containers are required for OTC iron products. Ingestion of iron tablets is treated with the chelating agent deferoxamine. Other chelating agents, deferiprone and deferasirox, are indicated for iron overload due to blood transfusions.
The mechanism of action of N-acetylcysteine (NAC) in acetaminophen overdose includes: (Select ALL that apply.) Answer AActing as a CYP2E1 inhibitor to block NAPQI production BIncreasing the conversion of acetaminophen to NAPQI C Causing conjugation of acetaminophen to acetaminophen sulfate DIncreasing the conversion of NAPQI to non-toxic substances EActing as a glutathione precursor FSpeeding up renal clearance of acetaminophen
de NAC is a free radical scavenger and glutathione precursor. Glutathione is necessary for converting the toxic metabolite NAPQI into non-toxic cysteine and mercapturic acid conjugates. NAC does not block CYP 2E1-mediated metabolism of acetaminophen, nor does it work to conjugate acetaminophen into its non-toxic sulfate form or impact renal clearance of the parent drug. Increasing the conversion of acetaminophen to NAPQI would worsen the overdose situation.
Which of the following is an early symptom of a nicotine overdose? Answer ABradycardia BSeizures CComa DLiver damage EAbdominal pain
e Nicotine overdoses have two phases of symptoms. The early symptoms include abdominal pain, nausea, diaphoresis, tachycardia and tremors. The later symptoms tend to be more severe and include bradycardia, dyspnea, lethargy, coma and seizures.
A hospitalized patient is using heparin. She requires immediate surgery. Which of the following agents will reverse the effects of heparin? Answer AKcentra BAtropine CIdarucizumab DPhytonadione EProtamine
e Protamine is the antidote for heparin and low-molecular weight heparin.
A 55-year-old man is doing landscaping in Arizona and is stung by a scorpion. Which of the following is the most appropriate treatment? Answer ASuccimer BCrotalidae polyvalent immune FAB CLevocarnitine DAntivenin immune FAB Centruroides EPralidoxime
Antivenin is anti-venom that can neutralize the venom left by the scorpion.
What is the antidote for acetaminophen overdose? Answer AThiamine BPyridoxine CNaloxone DFlumazenil EN-acetylcysteine
N-acetylcysteine administration results in regeneration of glutathione-S-transferase, which is needed for the clearance of the toxic metabolite NAPQI (it is converted to mercapturic acid which can then be excreted).
A patient is admitted to the hospital with alcohol intoxication. What should be administered to prevent alcohol-induced encephalopathy? Answer AThiamine BPyridoxine CFomepizole DHydroxocobalamin EPhytonadione
a Thiamine is vitamin B1. Chronic alcohol users can develop thiamine deficiency which can lead to neurological problems such as Wernicke's encephalopathy.
A 4-year-old child has accidentally ingested an unknown amount of Bengay, which contains methyl salicylate. She is experiencing hyperventilation, diaphoresis, nausea and vomiting. Which medication can be used to treat her condition? Answer ASodium bicarbonate BFlumazenil CMethylene blue DDeferoxamine ELipid emulsion 20%
a Topical agents, such as Bengay, can contain toxic amounts of salicylate, especially if consumed by a young child. Sodium bicarbonate is an alkalinizing agent to reverse salicylate toxicity.
Which of the following would be an expected presentation 12 hours after ingestion of a toxic acetaminophen dose? (Select ALL that apply.) Answer ANo symptoms BElevated INR CNausea and vomiting DFulminant hepatic failure EKidney failure
ac Phase 1 of acetaminophen overdose occurs 1-24 hours after ingestion. In phase 1, patients are commonly asymptomatic or have non-specific symptoms like nausea and vomiting. More severe symptoms (e.g., lab markers of hepatotoxicity, hepatic failure, renal failure) occur later.
A 24-year-old man has ingested belladonna or "deadly nightshade," which has anticholinergic effects. Which of the following are potential symptoms? (Select ALL that apply.) Answer ABlurry vision BMiosis CFlushing DDiarrhea EFrequent urination FHypothermia GDry skin
acg A few plants (notably belladonna), anticholinergic drugs (e.g., diphenhydramine) and some psychiatric medications can cause anticholinergic toxicity. Other symptoms include constipation, urinary retention and tachycardia.
The Rumack-Matthew nomogram is used to determine the need for which antidote? Answer ADimercaprol B N-acetylcysteine CDeferoxamine DPyridoxine EPralidoxime
b Acetaminophen levels are plotted on the Rumack-Matthew nomogram to determine the probability of hepatoxicity. If possible or probable hepatoxicity, NAC is given.
A mother finds her teenager unconscious on the floor with an empty bottle of amitriptyline next to him. Which of the following is the most important action to take? Answer AAdminister activated charcoal to prevent the amitriptyline from absorbing into the body. BCall 911 and assess circulation, airway and breathing; start CPR if needed. CAdminister ipecac syrup to induce vomiting. DCall the primary care physician after assessing circulation, airway and breathing. ETake him to the nearest urgent care center if he is breathing and has a pulse.
b Emergency help should be contacted immediately (911), and CPR should be performed if he is not breathing or does not have a pulse.
The antidote for methanol and ethylene glycol overdose is: Answer AN-acetylcysteine BFomepizole CNaloxone DCyanocobalamin EFlumazenil
b Fomepizole is a competitive inhibitor of alcohol dehydrogenase which is required for conversion of methanol and ethylene glycol (antifreeze) to its toxic metabolites. A second-line antidote would be ethanol.
A community in California was sprayed with an organophosphate pesticide. A child was outside when the plane flew over his yard. What symptoms of toxicity should his parents watch out for? Answer AAgitation, hypertension, tachycardia, flushing BEye tearing, salivation, vomiting, frequent bowel movements CPsychosis, self-hurt, anxiety, anger DTremors and seizures, ataxia, muscle spasticity ESedation, respiratory depression, tetanus
b These are cholinergic SLUDD symptoms: salivation, lacrimation, urination, diarrhea and defecation. The treatment for organophosphate poisoning is atropine (an anticholinergic). Pralidoxime can be used to treat muscle weakness and paralysis of respiratory muscles in severe cases.
