Section 1: History

Question 1

1.1 Given an exposure in which the signs and symptoms do not support the original history, identify
the causal agent(s).

Answer 1

1. Thorough study, especially of section 6 (drugs), and knowledge of expected effects from commonly encountered drugs and products will help to prepare for these questions.

Question 2

1.2 Given an exposure, identify the potential toxicity based on route of exposure.

Answer 2

1. Thorough study, especially of section 6 (drugs), will help to prepare for these questions. Pay special attention to drugs with varying toxicity depending on route of exposure.

Question 3

a. Ex Insulin

Answer 3

i. SQ, IM or IV is expected to lower blood sugar; however insulin ingested orally is deactivated in the GI tract and will not precipitate hypoglycemia.

Question 4

b. Ex SL Nitro

Answer 4

i. If dissolved in the mouth or under tongue, is expected to cause vasodilation. If swallowed whole, it is not effective.

Question 5

1.3 Identify the drugs with more significant toxicity in chronic exposure.

Answer 5

1. Consider examples of some drugs that have increased toxicity with chronic or acute-on-chronic ingestions.

Question 6

a. Aspirin:

Answer 6

Chronic or acute-on-chronic exposures may have more significant s/s than expected from a lower drug level. They may require more aggressive interventions at lower drug levels when compared to acute overdoses.

Question 7

b. Digoxin:

Answer 7

Presenting symptoms may be vague in a chronic ingestion. May see neuro s/s such as altered mental status, weakness, and seizures. Classic markers such as hypokalemia are not necessarily applicable in chronic exposure (K may be low, normal, or high). Ventricular dysrhythmias are more common in chronic exposures as compared to acute exposures.

Question 8

c. Fat soluble vitamins:

Answer 8

repeated or chronic over-ingestion places patient at more risk of developing symptoms or toxicity

Question 9

d. Lithium:

Answer 9

chronic or acute-on-chronic exposures may have more significant s/s than expected from a lower level. Chronic medication use may induce renal injury which will concomitantly produce a rise in drug level, thus worsening potential toxicity.

Question 10

e. Levothyroxine:

Answer 10

thyrotoxicosis is fairly common with chronic over-ingestion, but is uncommon in acute ingestion.

Question 11

f. Methotrexate:

Answer 11

significant toxicity is more common with repeated oral exposure vs a one-time acute ingestion (ex. If medication is taken daily instead of weekly)

Question 12

g. Valproate:

Answer 12

chronic or acute-on-chronic exposures may have more significant s/s than expected from a lower drug level.

Question 13

1.4 Identify plausible or implausible, age-appropriate scenarios.

Answer 13

1. Consider expected pediatric development in presented scenario to determine plausibility of
   reported exposure. Ex: a 9-mo-old child cannot developmentally open a child-resistant medication bottle and would not be expected to consume multiple tablets of medication without gumming or sucking on them.

Question 14

1.5 Given an exposure scenario (ingestion, ocular, dermal, or inhalation), identify the questions that
should be asked about the symptoms and signs.

Answer 14

1. Consider expected symptoms in regards to the specific product’s route of exposure.

Question 15

1.6 Identify which substance will present with late onset of clinical symptoms.

Answer 15

1. Consider examples of some drugs that have delayed onset of initial symptoms; or delayed onset
   of significant sequelae related to overdose.

Question 16

a. Acetaminophen:

Answer 16

delayed hepatic toxicity with minimal initial symptoms.

Question 17

b. Aspirin:

Answer 17

early signs of toxicity may be missed, especially in a mixed ingestion.

Question 18

c. Carbamazepine/Oxcarbazepine:

Answer 18

drug absorption is erratic and symptom onset may be

delayed.

Question 19

d. Colchicine:

Answer 19

symptoms of overdose present in three stages - the first phase, gastrointestinal symptoms, may be delayed for 8-12 hours from time of ingestion.

Question 20

e. Methadone:

Answer 20

recurrent, prolonged, or delayed CNS/respiratory depression is possible.

Question 21

f. Methotrexate:

Answer 21

pancytopenia.

Question 22

g. Napthalene (mothballs):

Answer 22

development of methemoglobinemia may be delayed (most concerning for patients with G6PD deficiency).

Question 23

h. Suboxone:

Answer 23

recurrent, prolonged, or delayed CNS/respiratory depression is possible, especially with children.

Question 24

i. Sulfonylureas:

Answer 24

may have delayed onset and persistent hypoglycemia.

Question 25

j. Thyroid replacement meds:

Answer 25

Symptoms from T3 ingestion may be delayed several hours; while symptoms from T4 ingestion may be delayed several days.

Question 26

k. Valproic Acid:

Answer 26

Symptoms may be delayed for several hours after overdose as drug metabolism causes rising ammonia levels, resulting in hyperammonemic encephalopathy and CNS depression. VA levels will rise first, followed by rising ammonia levels.

Question 27

l. Wellbutrin XR:

Answer 27

delayed seizures potentially in absence of other symptoms.

Question 28

1.7 Given a patient with specific symptoms who is taking a particular medication, identify what
additional history should be obtained.

Answer 28

1. This is an extension of a SPI’s daily activities. Examples:

Question 29

a. For a Benadryl ingestion

Answer 29

ask about anticholinergic symptoms, tachycardia, and QRS interval prolongation.

Question 30

b. For a Prozac ingestion

Answer 30

ask about CNS depression, serotonergic s/s, QTc prolongation, and GI upset.

Question 31

c. For a Lithium ingestion

Answer 31

ask about neuro s/s, Na level, and BUN/Cr.