Term
A patient has taken 12 tablets of her anti-depressant medication 30 minutes ago.
What should you do? |
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Definition
| Transfer to WIPC and observe for 6 hours to keep track of sustained release |
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Term
| Why keep people under observation longer when they have taken an overdose than if they had taken a normal dose of a drug? |
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Definition
| Half life of toxic agent may be longer. |
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Term
A patient presents with a Valproic acid overdose. He is confused, vomiting, and complaining of abdomimal pain.
Hi ammonia is 389 and is in liver failure. Which drug should you treat with?
1) Lactulose
2) Carnitine
3) Dextrose |
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Definition
2) Carnitine (IV if serious overdose)
VPA treats seizures by increasing GABA levels (increasing GAD and decreasing GABA transaminase)
However, it can disturb fatty acid metabolism (beta oxidation) and lead to hyperammonemia. It decreases carnitine levels, leading to fat accumulation in cytoplasm of cells (causing fatty liver) |
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Term
4 year old presents with altered mental status, seizures, bradycardia, hypotension and vomiting.
He has drunk a bottle of nail glue several hours ago, and now has an anion gap metabolic acidosis with venous lactic acid of 21.
What is going on? How do you treat? |
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Definition
Acetonitrile poisoning
Acetonitrile is metabolized to produce HCN (after 2-12h)
1) The Cyanide uncouples OX/Phos is mitochondria (inhibited cytochrome c oxidase found in complex IV) and leads to lactic acidosis by disrupting the TCA cycle.
2)
- Lily Antidote (Amyl and sodium nitrite, Sodium thiosulfate)- induce methhemoglobin, which binds CN with higher affinity than cytochrome C oxidase.
- Cyanokit (Hydroxycobalamin- b12)
- binds directly to CN- useful when Hb levels unknown |
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Term
| How is Theophylline used and what is special about its metabolism? |
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Definition
Enterohepatic metabolism.
Inhibits PDE, leading to increases in cAMP and ultimately to bronchodilation for respiratory disease |
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Term
| What therapies can minimize absorption? |
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Definition
1) Activated charcoal
- adsorbs chemical and toxins (H-binding, dipole and VDW)
- LARGE, UNCHARGED MOLECULES
- bad adverse effects
2) Gastric lavage
- limited effectiveness and aspiration risk
- Only use if potentially life-threatening and the procedure can be performed within 60 minutes
3) Whole Bowel irrigation
- sorbitol or polyethylene glycol increases motility (clear rectal effluent it goal)
use when retained metal or "body packers." |
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Term
| What factors influence toxin distribution? |
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Definition
1) pH of patient
2) Protein binding
3) Size and charge of molecule |
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Term
Patient presents with anion gap acidosis, respiratory alkylosis, tinnitus, vomiting and tachycardia.
What is going on? What do you do? |
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Definition
1) Salicylate toxicity (uncouples oxphos)
2) Dialysis and alklyzing serum pH (ion trapping) |
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Term
A 56 year old man presents after Elavil overdose. He is confused, tachycardic, mydriatic and dry. EKG shows wide complex tachyardia with QRS os 156ms.
What happened? What do you do? |
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Definition
1) Elavil (amitryptaline) is a weak acid TCA (prevents re-uptake of catecholamines by neurons)
2) Give systemic sodium bicarboninate so that TCA will bind to plasma proteins |
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Term
| Why can you use dialysis for patients with salicylate toxicity, but not for TCA toxicity? |
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Definition
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Term
Patient presents after drinking antifreeze. He is intoxicated with elevated osmolar gap, but has normal anion gap without acidosis.
What happened and what do you do? |
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Definition
1) Ethylene Glycol is metabolized into 2 toxic metabolites by alcohol DH
2) Inhibit its metabolism by giving ethanol or fomepizole (more potent Alcohol DH inhibitor) |
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Term
18 year old woman presents with recent ankle injury and has been taking large doses of OTC pain medications in last 3 days. She is found acidemic, confused, tachycardic and vomiting. Elevated liver function tests are shown and she is coagulopathic.
Whats going on and what do you do? |
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Definition
Acetaminophen overdose
1) NAPQI formed by CYP2e1 in liver depletes GST and exerts hepatotoxicity
2) Give N-acetylcystein (NAC), which replenishes Glutathione and binds up NAPQI |
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Term
76 year old presents with bipolar disorder and appears confused, tremulous and tachycardic. He had recent gastroenteritis with vomiting and diarrhea, and now has high sodium levels (hypernatremia).
What happened and what do you do? |
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Definition
Lithium poisoning
1) Competes with sodium for reabsorption in kidney
- dehydration increases retention of both Li and Na, as well as causing diabetes insipidus
2) IV fluids (dehydration)
- Hemodialysis (small cation, with low Vd and poor protein binding)
2) |
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Term
24 year old girl overdosed on risperidone and now presents comatose with pinpoint pupils.
HR is 162 and BP is 78/34. 2L of fluid result in minimal change.
What happened and what do you do? |
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Definition
Risperidone is a DA receptor antagonist that also acts on alpha-1 adrenergic receptors
Vital signs suggest there is an adrenergic issue with BP
1) Give Phenylephrine (pure alpha-1 antagonist) for vasodilation
2) Try Esmolol (B1- antagonist) for tachycardia, but RISKY with hypotension |
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Term
| What antidote should be given for insecticide poisoning? |
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Definition
| 1) Pralidoxime (noncompetitive inhibitor or anti-cholinesterase that binds allosterically and removes organophosphate from AChE) |
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