Ch 15. Toxicology Flashcards
What are the sympathomimetic drugs of abuse (4)
- Cocaine
- Amphetamines
- Cathinone’s (bath salts)
- Methcathinone (khat)
- Caffeine
How do you differentiate NMS, serotonin syndrome, and anticholinergic toxidromes? (3)
- All will be agitated, delirious.
- NMS and SS have fever, increased HR, increased BP, increased RR, rigidity. NMS has lead pipe cogwheel rigidity. SS has hyperreflexia and clonus. Serotonin syndrome: agitation, altered LOC, restless, hyperthermia, tachycardia, tachypnea, rigidity, hyper-reflexia, tremor, and MYOCLONUS
- Exposure: AntiCh – TCA or an anti drug. Serotonin Syndrome (antidepressants) has a predictable effect of excess serotonin and tends to come on quickly and go away quickly (24-48 hrs). NMS (antipsychotics) has a much more indolent onset (Scott Luckyk Grandma Fever – elderly individual has been acting funny for a few days and now she has a fever). It has a less predictable onset and may not go away for days to weeks. It is rare and a diagnosis of exclusion.
What is your hot and crazy DDx? (6)
- Sympathomimetics: Cocaine, Meth, Caffeine, Anticholinergics (TCA, plants Jimson weed)
- Syndromes: Serotonin Syndrome, Neuroleptic Malignant Sydrome, Malignant Hyperthermia
- Infectious: Sepsis, Meningitis, Encephalitis
- Metabolic: Pheochromocytoma, Thyrotoxicosis
5. Environmental: Heat stroke - Toxicological: Aspirin, Dinitrophenol (DNP), withdrawal from EtOH, Benzodiazepines, MDMA
What are your anticholinergics (5)
- Antidepressants
- Antipsychotics
- Antihistamines (dimenhydrinate)
- TCA
- Gimsum weed (plants)
Anticholinergic toxidrome (6)
“Mad as a hatter, dry as a bone, red as a beet, blind as a bad, hot as Hades, the bowel and bladder lose their tone and the heart runs alone”
- Fever
- Dry
- Altered mental status
- Tachycardia
- Urinary retention
- Decreased bowel sounds
- Mydriasis (dilated pupils)
Cholinergic toxidrome (8)
- Diaphoresis
- Vomiting
- Diarrhea
- Miosis
- Salivation
6. Urinary incontinence - Bronchorrhea
- Bronchospasm
- Bradycardia
Rx. Atropine
Treatment of anticholinergic toxicity (3)
- Supportive
- Physostigmine 1-2mg IV for adults over 5-10mins, start with 0.1mg or 0.2mg and watch the HR closely. -Beware bradycardia/seizure/cholinergic effects, but probably very safe!
- Sodium bicarb for wide complex QRS, QTprolongation (sodium channel blockade, ex TCA)
Cyanide poisoning Sx and antidote (2)
- Consider in all significant smoke inhalations, especially industrial fires, with metabolic acidosis, neuro dysfunction, elevated lactate
1. Sx = HA, anxiety, confusion, coma, seizures, tachy or brady dysrhythmia, abdo pain, flushing, renal failure, rhabdo (Basically all of your cells shut down)
2. Cyanide antidote = cyanokit (hydroxycobalamin, sodium thiosulfate)
How much oxygen does this deliver (3)
- Nasal cannula 6L/min =
- Simple oxygen facemask 10L/min =
- Facemask NRB 15L/min =
- Nasal cannula 6L/min = 40%
- Simple oxygen facemask 10L/min = 50%
- Facemask NRB 15L/min = 95%
Name the antidote: 1. CCB: 2. BB: 3. Cyanide: 4. Digoxin: 5. Benzodiazepines: 6. Local anaesthetic: 7. Oxidizing toxins (nitrites, benzocaine, sulfonamide): 8. Isoniazid: 9. TCA: 10. Serotonin syndrome: 11. NMS: 12. Carbon monoxide: 13. Cholinergic (pesticides): 14. Anti-cholinergic 15. Toxic alcohol (methanol, ethylene glycol): 16. Rattlesnake (Crotiladae envenomation): 17. Iron:
- CCB: calcium chloride, high dose insulin, glucagon, Norepi, intralipid, atropine, pacing
- BB: calcium chloride, high dose insulin, glucagon, vasopressors, intralipid, atropine, pacing
- Cyanide: cyanide antidote kit (amyl nitrite, or sodium nitrite)
- Digoxin: digibind
- Benzodiazepines: Flumazenil
- Local anaesthetic: intralipid
7. Oxidizing toxins (nitrites, benzocaine, sulfonamide): methylene blue - Isoniazid: pyridoxine (B12)
- TCA: sodium bicarb
- Serotonin syndrome: supportive, and cyproheptadine
11. NMS: supportive, and bromocriptine/dantrolene
12. Carbon monoxide: 100% FiO2, hyperbaric oxygen * Consider in your altered patient, smoke/exhaust exposure, elevated lactate *
13. Cholinergic (pesticides): atropine q5min. Repeat indefinetly. - Anti-cholinergic: physostigmine
- Toxic alcohol (methanol, ethylene glycol): Fomepizole
- Rattlesnake (Crotiladae envenomation): Cro-Fab
- Iron: Defuroxamine
Salicylate toxidrome (5)
- ASA, oil of wintergreen (methyl salicylate)
1. Altered mental status
2. Tinnitus
3. Metabolic acidosis, respiratory alkalosis
4. Tachycardia, tachypnea, arrhythmias, shock
5. N+V
6. Diaphoresis
Activated charcoal does NOT bind these things (6)
* PHAILS * 1. Pesticides 2. Hydrocarbons and heavy metals 3. Alcohol 4. Iron 5. Lithium 6. Solvents
Three options for decontamination (3)
- Gastric lavage
- Charcoal
- Whole bowel irrigation
How do you do urinary alkalinisation? (3)
- Bolus 1-2mEq/kg IV sodium bicarb
- 2 amps of sodium bicarb in 800mL D5W, infuse at 200mL/hour
- May need 20mEq KCl
- Monitor VBG q2hours for K+ and bicarb
- Aim for urine pH 7.5-8.5
ECG features of TCA toxicity (3)
*TCA’s block fast sodium channels * 1. Wide QRS, with a slurred S wave 2. Tachycardia 3. Brugada pattern 4. Heart blocks and bradycardia 5. Ventricular tachycardia 6. Prolonged QT 7. Right axis deviation (slurred S wave)
Indication for activated charcoal (example: TCA overdose) (1)
- Awake, alert, patent airway, bad toxicity, and within 1 hour of ingestion
Bupropion overdose patients are more at risk of __________ (1)
- Seizures (also agitation, tremor, N+V, sinus tachycardia)
Patients taking trazadone are at risk of ________ (1)
- Priapism
Symptoms of SSRI overdose (1)
- Nausea, vomiting, sedation, tremor, sinus tachycardia, seizures, serotonin syndrome ECG: Prolonged QRS and QT Bad ones: venlafaxine, bupropion
Treatment options for toxicology seizures (3)
- Benzodiazepines
- Phenobarbital
- Propofol * Do not use phenytoin (dilantin) for toxicology seizures *
What do you worry about in MAOI overdose? (2)
Narrow therapeutic window. Can cause toxicity at therapeutic levels. One pill can kill a toddler.
- Serotonin syndrome
- Tyramine reaction (headache with dietary indiscretion)
Symptoms of anti-psychotic overdose (4)
- Basically the same Sx the drug cause but more of it *
1. CNS depression, lethargy, ataxia, confusion 2. Respiratory depression in severe cases
3. Some can have antimuscarinic (tachy, dry skin, urinary retention, delirium, fever)
4. Sinus tachy (prolonged PR, QRS, QT)
Worrisome side-effect of clozapine? (1)
- Agranulocytosis
Treatment options for Torsade de pointe (2)
- Shock (200J)
- Magnesium 2g bolus
- Overdrive pacing