Toxicology Lecture

Question 1

MC antidepressants to cause OD related deaths

Answer 1

Tricyclic antidepressants

Question 2

Altered mental status
Sinus tachycardia

serious toxicity seen within 6 hours:
coma, cardiac conduction delays, supraventricular tachycardia, hypotension, respiratory depression, premature ventricular beats, v tach, seizures

Answer 2

Tricyclic OD

Question 3

R axis deviation
Terminal R wave in aVR
Widened QRS

ECG changes seen within ____ hours of a tricyclic OD

Answer 3

6 hours!

Question 4

Shock
Prolonged QRS
Terminal R waves in aVR
Altered mental status

Answer 4

Tricyclic OD

Question 5

MC tricyclic that is taken for OD

Answer 5

amitriptyline

Question 6

Peak absorption is 1 hour
Toxic dose= 10-20 mg/kg

Answer 6

Tricyclic OD

Question 7

O2, IV, monitor

BICARB!! 1-2 mEq/kg until blood pH equals 7.50-7.55

intubate if necessary

Answer 7

Tx for tricyclic OD

Question 8

sx: agitation, confusion, tremor, rigidity, sweating, hyper-reflexia, anxiety, ataxia
ie. .a pt took a whole bottle of their SSRIs

Answer 8

Serotonin syndrome

Question 9

SSRIs cause ____ symptoms

Answer 9

psych!

(hyperreflexia, rigidity, agitation)

Question 10

Due to hyper-reflexia, rigidity, myoclonus etc…pts who OD on SSRIs (serotonin syndrome) can give themselves…

Answer 10

Rhabdo

Question 11

Tx for serotonin syndrome?

Answer 11

Benzos

Question 12

__-___% of patients on long term lithium therapy will develop toxicity

Answer 12

75-90%

Question 13

Hand tremor, polyuria, rash
Nephrogenic diabetes insipidus

Neuro effects: memory loss, decreased mental status, fatigue, ataxia, dysarthria
N/V/D

Hypotension, conduction delays, ventricular dysrhythmias
QT prolongation, ST segment depression, T wave inversion

Answer 13

Lithium OD

very narrow therapuetic index, make sure these pts stay hydrated!

Question 14

0-12 hours: CNS effects
pt appears intoxicated without smell of ethanol on breath

12-24 hrs: cardiopulmonary effects
tachycardia, tachypnea, HTN
CHF, ARDS, circulatory collapse

24-72 hours: renal effects
flank pain, CVA tenderness, acute tubular necrosis with acute renal failure

Answer 14

Ethylene glycol OD

Question 15

Metabolic acidosis with elevated anion gap and elevated osmolal gap

Answer 15

Ethylene glycol OD

Question 16

Serum osmolal= 10
Calculated osmolal= 3.8

..what are you missing?

Answer 16

Ethylene glycol OD!

conversion factor for Ethylene Glycol= 6.2, which is the difference between the serum and calculated levels

Question 17

Ethylene glycol= 6.2
Methanol= 3.2
Ethanol= 4.6

Answer 17

conversion factors

Question 18

Fomepizole=DOC!

Also give bicarb to correct acidosis

end game=dialysis!!

(but this is expensive, so cheap alcohol will also work)

Answer 18

Treatment for ethylene glycol OD

Question 19

What is MUDPILES?

Answer 19

causes of elevated anion gap

• *M**ethanol
• *U**remia
• *D**KA
• *P**ropylene glycol
• *I**nfection/isonizid
• *L**actic acidosis
• *E**thylene glycol/ethanol
• *S**alicylates

Question 20

Na- (Bicarb + Cl)

Answer 20

Anion gap

normal= 12 or under

Question 21

What is a normal anion gap?

Answer 21

12 or under

Question 22

Kussmal’s breathing (hyperventilation)
Tinnitis

Answer 22

Aspirin OD!

Question 23

If a pt has kussmal’s respirations, you can pretty much assume they are in what?

Answer 23

Metabolic acidosis

(body is trying to blow off CO2 to compensate)

Question 24

less than 150 mg/kg ingestion of aspirin

Answer 24

non toxic to mild

Question 25

150-300 mg/kg of aspirin

Answer 25

mild to moderate toxicity

Question 26

300-500 mg/kg of aspirin

Answer 26

serious toxicity!

Question 27

\>500 mg/kg of aspirin

Answer 27

Potentially life threatening

Question 28

For a suspected aspirin OD, you must repeat serum salicylate levels ever 2 hours for __ hours

Answer 28

6 hours (toxic levels are usually apparent within 6 hours)

Question 29

increased anion gap metabolic acidosis, metabolic alkalosis and respiratory alkalosis

Answer 29

Aspirin OD

Question 30

Is the Done monogram useful for Aspirin ODs?

Answer 30

NO

Question 31

Monitor urine pH and maintain at 7.5-8.0 | (alkalize the urine)

Answer 31

Aspirin OD

Question 32

What is the ultimate treatment of choice for Aspirin OD?

Answer 32

Dialysis

Question 33

For an Aspirin OD, gastric lavage can be done within the first...

Answer 33

60 mins

Question 34

What is the max dose for Tylenol in adults?

Answer 34

4 grams

Question 35

MC cause of acute liver failure in US?

Answer 35

Tylenol

Question 36

What age group does the best with Tylenol ODs?

Answer 36

Kids under 5 (bc they have more Glutathione in liver, which makes it easier to metabolize Tylenol)

Question 37

What is the worst possible thing you could do in addition to ODing on Tylenol

Answer 37

Drinking alcohol with it!! (same enzyme metabolizes both)

Question 38

phase 1 (0-24 hrs) asymptomatic to N/V Subclinical **bump in LFTs** (this is the first sign!)

Answer 38

Tylenol OD

Question 39

Phase 2 (18-72 hours) RUQ pain N/V Continued increase in LFTs

Answer 39

Tylenol OD

Question 40

Phase 3 (72-96 hours) Jaundiced Coagulopathy Fatality Liver necrosis Renal failure

Answer 40

Tylenol OD

Question 41

When is the max absorption in a Tylenol OD?

Answer 41

4 hours (so get labs right away and repeat at 4 hours)

Question 42

Plot levels at 4 hours on _______ \_\_\_\_\_\_\_ to determine if hepatic toxicity is likely

Answer 42

Rumack Nomogram

Question 43

Can you use the Rumack Nomogram if 2+ drugs wee taken or if the pt delays the trip to the ER?

Answer 43

NO

Question 44

What should the blood pH be in a Tylenol OD?

Answer 44

Normal! (if pt has acidosis, there must be another agent on board)

Question 45

N-acetylcysteine (NAC) is the antidote for....

Answer 45

Tylenol OD

Question 46

What is the time frame you want to give N-Acetylcysteine in?

Answer 46

best if within 8 hours (but can give anytime, even if pregnant)

Question 47

pH \<7.3 Grade 3+ encephalopathy PT \>100 Serum Cr \> 3.4

Answer 47

Liver transplant requirements

Question 48

True or False.. N-acetly-p-benzoquinoneimine (NAPQI) is the toxic metabolite of Acetaminophen

Answer 48

True

Question 49

Bradycardia + hypotension **serious ingestion when \>1 gram** onset= 15 mins - 2 hours

Answer 49

Verapamil OD (physiologically, this combination does not make sense)

Question 50

DOC for CCB (Verapamil) OD?

Answer 50

CaCl 10% 10-20 mg q30 minsx 8 hours

Question 51

DOC for beta-blocker OD

Answer 51

Glucagon

Question 52

Time to peak effect of opiates for the following methods: IV Crush/snort IM Oral Transdermal

Answer 52

``` IV= 10 mins Snort= 10-15 mins IM= 30-45 mins Oral= 90 mins Transdermal= 2-4 hours ```

Question 53

Pressors and Atropine can be given as support tx (CaCl=DOC!!) \*often see high grade blocks of ECG

Answer 53

Verapamil OD