Class 4 (02|01|22) Toxicology - Overdose & Poisonings

Question 1

What are toxidromes?
What do they help with?
Is it a perfect science?

Answer 1

a group of clinical signs and symptoms associated with a toxic ingestion or exposure (often with overdosage)

Help with the identification of common signs and symptom pt are presenting with which help HCP determine the class of drugs uses 
Combination of specific signs and symptoms that reflect drug class effects on particular neuroreceptors 

Imperfect because symptoms from multiple toxins can overlap, clouding the clinical picture

Question 2

Toxidormes Classication

Answer 2

Downers
opioid
Sedative-Hypnotic
Cholinergic

Fast & Furious
Anticholinergic
Sympathomimetic

Question 3

Downers — OPIOIDS

examples

Answer 3

Morphine, Codine, Tramado, Heroin, Meperidine, Diphenoxylate, Hydromorphone, Fentanyl, Methadone, Propoxyphene, Pentazocine, DXM, Oxycodone, Hydrocodone

Question 4

Downers — OPIOIDS

pathophysiology

Answer 4

stimulate three receptors in the CNS and PNS

Question 5

Downers — OPIOIDS

main use

Answer 5

MAIN USE: analgesic properties — inhibits nociceptive information in the nervous system (prevents transmission of pain to the brain
Euphoria — increases dopamine release
Anxiolysis — lower anxiety

Question 6

Downers — OPIOIDS

s/s

Answer 6

Heart Rate: decrease 
Resp Rate: decrease 
Temp: decrease 
Pupils: pinpoint/constricted 
Bowel sounds: decrease 
Skin: normal
Mental status: depressed

Question 7

Downers — OPIOIDS

management

Answer 7

ABCDE approach
Naloxone-: block effect of opioid
Blood Glucose:hypoglycemia can present similarly
GI decontamination: risk for aspiration so a later resort

Question 8

Downers — OPIOIDS

significant clinical findings

Answer 8

resp rate > 12 is usually the best indicator

Look for tach marks

Question 9

Downers — SEDATIVE-HYPNOTIC

examples

Answer 9

Anti-anxiety agents, muscle relaxants, antiepileptics and preanesthetic medications -Barbiturates - Benzodiazepines

Question 10

Downers — SEDATIVE-HYPNOTIC

treatment/managment

Answer 10

ABCDE approach — focusing on the life threatening aspects (cardio, resp depression)
Dialysis in order to clear the toxins
Flumazenil: Benzo - antagonist: blocks the effects of the benzodiazepines

Question 11

Downers — SEDATIVE-HYPNOTIC

s/s

Answer 11

Heart Rate: decrease 
Resp Rate: decrease 
Temp: decrease 
Pupils: no change 
Bowel sounds: decrease 
Skin: normal
Mental status: depressed

Question 12

Downers — SEDATIVE-HYPNOTIC

useages

Answer 12

Choral hydrate: sedation in hospital

Rohypnol: date-rape-drug (gamma hydroxybutyrate)

Question 13

Downers — SEDATIVE-HYPNOTIC

patho

Answer 13

enhance the effect of the GABA transmitter that blocks impulse nerve cells and brain
Increase GABA/blockage, they can improve mood and anxiety
When taxes in excess, end up with toxidrome: sedative and hypnotic

Question 14

Downers — SEDATIVE-HYPNOTIC

what present similarly

Answer 14

signs and symptoms of the over dose can look like alcohol usage

Question 15

What is Flumazenil?

Answer 15

Flumazenil: Benzo - antagonist: blocks the effects of the benzodiazepines (Downers — SEDATIVE-HYPNOTIC)

Antagonsis

Question 16

Downers — CHOLINERGIC

examples

Answer 16

Organic Phosphorous Compounds: Carbamates, Arecholine, Pilocarpine, Urecholine (Betanechol), Carbachol, Choline, Metacholine, Mushrooms

Question 17

Downers — CHOLINERGIC

common uses

Answer 17

found in agriculture and chemicals

Included in medications

Question 18

Downers — CHOLINERGIC

patho

Answer 18

increase levels of acetylcholine at the neuromuscular junction due to the inactivity of the acetylcholine enzyme which would normally break down acetylcholine
Results with increase levels and longer duration at the receptor of acetylcholine
Symptoms arise when the receptors found: smooth muscle of GI, bronchi, heart, salivary & sweat glands, and ciliary body of eye

Question 19

Downers — CHOLINERGIC
“classic” set of s/s
SLUDGE

Answer 19

Increase salivation and sweating 
increase lacrimation
increase urinary incontinence 
increase diarrhea
increase GI cramps
increase emesis

Question 20

Downers — CHOLINERGIC

s/s

Answer 20

Heart Rate: no change - decrease 
Resp Rate: no change 
Temp: no change  
Pupils: pinpoint/constricted 
Bowel sounds: increase
Skin: diaphoresis 
Mental status: depressed, confused, seizures

Question 21

Downers — CHOLINERGIC

treatment/management

Answer 21

• anticholinergic medications: atropine (IV) | diazepam: treat seizures

Question 22

Fast & Furious — ANTICHOLINERGIC

examplese

Answer 22

Anticholinergics - Atropine, scopolamine, glycopyrrolate benztropine, trihexyphenidyl
Antihistamines - chlorpheniramine, cyproheptadine, doxylamine, hydroxyzine, dimenhydrinate, diphenhydramine, meclizine promethazine

Question 23

Fast & Furious — ANTICHOLINERGIC

common uses

Answer 23

Tricyclic antidepressants, muscle relaxants, anti-psychotics, antimuscarinic agents for an overactive bladder (Oxybutlnin)
Plants

Question 24

Fast & Furious — ANTICHOLINERGIC

patho

Answer 24

inhibition of the muscarinic cholingeric neurotransmission: block the acetylcholine from blinding to receptors (blocks parasympathetic nervous system and body will enter fight to flight mode with no regulation)
Reports can be found on the smooth muscle on the Gi tract, bladder, heart, sweat glands, ciliary of eye, salivary glands

Question 25

Fast & Furious — ANTICHOLINERGIC | s/s

Answer 25

``` Heart Rate: increase Resp Rate: no change Temp: increase Pupils: dilated Bowel sounds: decrease Skin: normal - dry Mental status: depressed, confused, hallucinations, seizures ```

Question 26

``` Fast & Furious — ANTICHOLINERGIC memorization technique (5) ```

Answer 26

``` Mad as a hatter - altered mental status blind as a bat - mydriasis red as a beet - flushed skin hot as a hare - skin dry dry as a bone - dry mucous membranes ```

Question 27

Fast & Furious — ANTICHOLINERGIC | significant clinical findings

Answer 27

body cannot sweat so it regulates body temp by becoming hyperthermic Tachycardia: earliest and most reliable s/s

Question 28

Fast & Furious — ANTICHOLINERGIC | treatment

Answer 28

ABCDE approach: Gastric decom. : activated charcoal Diazepam: calm, treat seizures Physostigmine salicylate: antidote for anticholingeric toxicity

Question 29

What is physostigmine salicylate?

Answer 29

Physostigmine salicylate: antidote for anticholingeric toxicity

Question 30

Fast & Furious — SYMPATHOMIMETIC examples where is it found in medication?

Answer 30

Caffeine, cocaine, amphetamines, methamphetamines, ritalin, LSD, Theophylline, MDMA Medication: E, NE, dopamine

Question 31

Fast & Furious — SYMPATHOMIMETIC | patho

Answer 31

CNS stimulation increase because increased circulating levels of catecholamines (E/NE and dopamine) Causes reduced catecholamine re-uptake at the pre-ganglionic synapse (body in fight or flight and unable calm itself down)

Question 32

Fast & Furious — SYMPATHOMIMETIC | s/s

Answer 32

``` Heart Rate: increase Resp Rate: increase Temp: increase Pupils: dilated Bowel sounds: increase Skin: diaphoresis Mental status: alert, agitated, seizures ```

Question 33

Fast & Furious — SYMPATHOMIMETIC | significant clinical findings

Answer 33

hyperthermia here can result in rhabdomyolysis and brain injury acidosis and essentially disseminated intravascular coagulation — life-threatening cerebral hemorrhage Agitation, psychosis, seizures, responsive dilated pupils Can lead to excited delirium COMMON causes of death: intracerebral haemorrhage, hyperthermia and arrhythmias (VIA acidosis, tachycardia and hypertension)

Question 34

Fast & Furious — SYMPATHOMIMETIC | treatment

Answer 34

ABCDE approach Hyperthermic: cool, ice packs, fans, Cooling blanket Hypertension: nipride- potent vasodilator (IV) Diazepam: slow body down and help control seizures

Question 35

Using toxidromes, what should be assessed/affect the airway?

Answer 35

Look for signs of inability to protect airway (secretions, vomiting) LOC decreased to the extent of unable to protect airway GCS comma scan <8 Implement interventions if needed

Question 36

Using toxidromes, what should be assessed/affect the breathing?

Answer 36

(Rate, Depth) | - intervene: beg valve mask ventilation, O2

Question 37

Using toxidromes, what should be assessed/affect the circulation?

Answer 37

Careful attentions to colour of skin and diaphoresis/dryness

Question 38

Using toxidromes, what should be assessed/affect the disability?

Answer 38

GCS: responsive, unresponsive Pupils Movement of extremities Glucose: s/s can mimic hypoglycaemic

Question 39

Using toxidromes, what should be assessed/affect the Elimination/Exposures?

Answer 39

``` Remove clothing Transdermal patches External contaminants: substance on clothing or personal Measure temp Look for tack marks Skin infections ```

Question 40

What does the following diagnostic testing indicate? blood glucose CBC, electrolytes BUN/Cr

Answer 40

Blood glucose: baseline, rule out hypoglycaemia CBC, electrolytes: baseline, risk of arrhythmias with certain toxins, fluid balance BUN/Cr: evaluate the kidney function and the risk of rhabdomyolysis

Question 41

What is rhabdomyolysis?

Answer 41

rhabdomyolysis: when the skeletal muscle fibres begin to break down and the muscle content leak into circulations (can happen in certain toxin overdoses

Question 42

What does the following diagnostic testing indicate? liver enzymes INR/Ptt Serum osmolality

Answer 42

liver enzymes: want baseline for liver function, determine if there abnormalities to make it difficult to excerpt toxin INR/Ptt: asses risk increase risk of bleeding Serum osmolality: what substance are dissolved in our blood; sodium glucose and urea are primary substance

Question 43

What does the following diagnostic testing indicate? Lactate Urinalysis Beta-HCG

Answer 43

Lactate: acidotic determine through arterial blood gas urinalysis: aspirin overdose - help determine treatment to affect the alkalinization of the urine Beta-HCG: pregnant

Question 44

What does the following diagnostic testing indicate? Troponin CK Tox Screen

Answer 44

Troponin: myocardial damage CK (creatinine kinase: skeletal muscle damage Tox screen: Serum (ASA, alcohol, acetaminophen etc) and urine — help determine how much is in the system or how much has been eliminated

Question 45

Using toxidromes, what should be done for management for airway?

Answer 45

- intubate if not protecting airway (GCS >8)

Question 46

Using toxidromes, what should be done for management for breathing?

Answer 46

provide oxygen and respiratory support as needed | Respiratory support: mechanical ventilation, beg valve mask ventilation

Question 47

Using toxidromes, what should be done for management for circulation?

Answer 47

vascular access: IV IV fluids/pressors as needed: rehydrate to clear toxins, if BP is low Insert folet

Question 48

Using toxidromes, what should be done for management for Disability?

Answer 48

treat hypo/hyperglycemia if present

Question 49

Using toxidromes, what should be done for management for Elimination/exposures?

Answer 49

- remove clothing transdermal patches, external contaminants

Question 50

What can be done to manage to reduce absorption with drug toxicity?

Answer 50

Gastric decontamination

Question 51

Describe Gastric decontamination

Answer 51

REDUCING ABSORPTIOM activated charcoal is a special form of carbon that can bind other substances on its surface Used to absorb drugs in the GI tract to reduce absorption (VIA drink or nasal gastric tube) Advers effects: nausea, vomiting

Question 52

what can be done to manage to reduce metabolism with drug toxicity? examples (4)

Answer 52

Antidote or competitive inhibitors Narcan (Naloxone) Flumazenil (benzodiazepine antagonist/antidote: sedative-hypnotic) Physostigmine (anticholinergic antidote) Atropine (cholinergic antidote)

Question 53

Describe the mechanism of action of the competitive inhibitor Narcan (Naloxone).

Answer 53

``` Opioid antagonist (VIA competes the receptor site so opioid cannot but uptake) - nasal spray or injection (IM/SC) Only works w opioids ```

Question 54

Describe the mechanism of action of the competitive inhibitor Flumazenil (benzodiazepine antagonist/antidote)

Answer 54

Flumazenil (benzodiazepine antagonist/antidote): compete for the receptors

Question 55

Describe the mechanism of action of the competitive inhibitor Physostigmine (anticholinergic antidote)/

Answer 55

reverse the effects of the anti-cholinergic by increase the level of acetylcholine at the site of transmission (IV, IM)

Question 56

Describe the mechanism of action of the competitive inhibitor Atropine.

Answer 56

competitive antagonist of muscarinic receptors - competitive inhibition of the postganglionic acetylcholine receptors which leads to the parasympathetic inhibition of the acetylcholine receptor in the smooth muscle IV, subQ, endotracheal tube, IM

Question 57

Using toxidromes, what examples for management for elimination? (4)

Answer 57

Alkalinization of the blood or urine Hydration (IV fluids) Hemodialysis saline diuresis

Question 58

In management of drug toxicity, how does Alkalinization of the blood or urine work?

Answer 58

Alkalinization of the blood or urine: alter the urine pH to increase excretion Sodium bicarbonate: pH >7.5 allows more drug to be excrete through the urine (used in aspirin OD’s)

Question 59

In management of drug toxicity, how does Hydration (IV fluids) work?

Answer 59

Hydration (IV fluids): increases volume of urinary fluids

Question 60

In management of drug toxicity, how does

Question 61

When is hemodialysis commonly used?

Answer 61

Common: alcohol, ethylene glycol methanol OD’s, lithium, acetaminophen, aspirin, dilantin

Question 62

In management of drug toxicity how does saline diuresis work?

Answer 62

patient dehydrated where admin of fluid will increase excretion of the toxin/substance

Question 63

How are Antihypertensives used to manage overdoses?

Answer 63

Pt presenting with sympathomimetic toxidromes - hypertension is common Nipride

Question 64

What are the s/s of the first phase of Acetaminophen Overdose?

Answer 64

``` 1st 24 hours S/s not specific n/a unwell asymptomatic ```

Question 65

What are the s/s of the second phase of Acetaminophen Overdose?

Answer 65

24-72 hours (1-3 days) Elevation in liver function test: AST & ALT, billrium, prothrombin time Right upper qua pain

Question 66

What are the s/s and time period of the third phase of Acetaminophen Overdose?

Answer 66

72-96 hours (3-5 days) Liver becomes necrotic: s/s liver dysfunction Hepatic encephalopathy: VIA ammonia level increasing Bleeding Hypoglycemia

Question 67

What are the s/s and time period of the fourth phase of Acetaminophen Overdose?

Answer 67

5-7 days Complete resolutions if damage cause is reversible OR Liver transplant

Question 68

What is the treatment of Acetaminophen Overdose?

Answer 68

Treated with NAC (w in 8 hours) N-acetylcysteine (Parvolex/Mucomyst) Administered intravenously Not an antidote but interferes with the binding to reduce absorption and metabolism of the drug

Question 69

Describe Acetaminophen Overdose — Pathophysiologic Effects.

Answer 69

``` Acidic environments (stomach) allow for more drug absorption compared with tissue at a hight pH May cause spasm of pyloric sphincter Small amount excreted unchanged in urine ```

Question 70

What significant parts of the body does Salicylate Overdose affect?

Answer 70

It is an acid to when there is an overdosage, it ends up effecting the cardiac myocardial function which contributes to toxicity Acid environment of stomach aids absorption (food delays absorption)

Question 71

What are the early symptoms of a Salicylate Overdose?

Answer 71

Nausea Vomiting Dizziness Tinnitus: ringing in ears

Question 72

What symptoms indicate moderate toxicity in Salicylate Overdose? (>250mg/kg)

Answer 72

``` tachypnea Hyperpyrexia Sweating Dehydration Agitation Ataxia Restlessness ```

Question 73

What symptoms indicate severe toxicity in Salicylate Overdose? (>500mg/kg)

Answer 73

``` hypotension Metabolic acidosis Cerebral edema Oliguria Renal failure Coma Seizure Acidosis can cause cardiac dysrhythmias and cardiac failure ```

Question 74

Describe the impact Salicylate Overdose has on the body. (resp, blood glucose, cerebral edema, cardiac, kidneys)

Answer 74

respiratory: respiratory alkalosis Glucose homeostasis affected: interference of the KREB’s cycle (glycogen depleted results with low serum glucose levels) Cerebral edema: increase Myocardial depression and hypotension from the increasing acidic Kidneys eliminate HCO3-, Na+ and K+: bc of increase acidosis Need to admin electrolytes to stabilize ^

Question 75

What are the 6 phases of a basic approach to a poisoned patients?

Answer 75

(1) immediate assessment and stabilization (2) laboratory assessment, (3) decontamination, (4) administration of an antidote, (5) elimination enhancement of the toxin, and (6) disposition

Question 76

What are the 5 basic intervention/management of a poisoned patient?

Answer 76

high flow oxygen for pt w suspected poisoning or ingestion and exhibit resp compromise Blood glucose taken - hypoglycaemic 50mL of 50% dextrose 100 mg thiamine for Wernicke’s encephalopathy or alcohol use Naloxone max 2 mg @ 0.1mg/kg Seizure control - benzodiazepines & pyridoxine (vit. B6)