Toxicology
Antidepressants and Pesticides
(Illustrated by the Book of Bunny Suicides)
A 25-year-old female with a history of depression was
found unconscious. She has a non focal exam and she
gets intubated. T 99.0F; HR 140/min; RR 14 on vent; BP
80/40 mmHg. Pupils are midpoint and reactive and
axillae are dry. An ECG shows sinus tachycardia with a
QRS interval of 0.15 seconds. ABG: pH 7.42; pCO2 37,
PO2 106. Your next step should be to give:
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A. glucagon.
B. physostigmine.
C. propranolol.
D. sodium bicarb.
E. calcium.
In a pt with suspected serotonin
syndrome, it is reasonable to
give:
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A. benztropine (Cogentin).
B. bromocriptine.
C. cyproheptadine.
D. dantrolene.
E. ondansetron
The most significant toxicity of a
pure bupropion (Wellbutrin)
overdose is:
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A. neuroleptic malignant syndrome.
B. orthostasis.
C. seizures.
D. serotonin syndrome.
E. wide complex
tachycardia.
Which of the following is
CORRECT regarding an overdose
of tranylcypromine (Parnate):
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A. asymp pts need 24hrs of obs
B. bradycardia & hypotension occur early in
the course
C. beta blockers are the drug of choice for
ventricular dysrhythmias
D. hemodialysis should be considered for
severe ODs
E. sxs start w/in 1-2hrs of the overdose
Pralidoxime (2-PAM) reverses
organophosphate poisoning by:
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A. a direct beta-agonist effect which treats
bradycardia.
B. increasing acetylcholine release from nerve
endings.
C. increasing norepinephrine release from nerve
endings.
D. breaking down the organophosphate
molecules
E. reversing the inhibition of acetylcholinesterase.
As an antidote, pralidoxime (2PAM) is:
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A. typically used before atropine
B. effective against chlorinated hydrocarbon
insecticides.
C. necessary to treat carbamate insecticide toxicity.
D. is often given in conjunction with physostigmine.
E. necessary to reverse nicotinic effects of insecticide
poisoning.
A 2-year-old boy is found unresponsive a
barn with muscle twitching, vomiting,
diarrhea, and wheezing. It is likely he has
accidentally ingested:
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A. parathion.
B. jimson weed.
C. DDT.
D. nitrate fertilizers.
E. Oil of wintergreen.
A potentially lethal medication
combination would be:
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A. phenelzine (Nardil) and meperidine
(Demerol).
B. imipramine (Tofranil) and
bronchodilators.
C. lithium and acetaminophen (Tylenol).
D. theophylline and high dose steroids.
E. thioridazine (Mellaril) and cimetidine
(Tagamet).
Which of the following EKG abnormalities
is NOT expected in a TCA overdose?
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A. Prolonged QT interval
B. QRS interval 0.13 seconds
C. Right axis deviation
D. Shortened PR interval
E. Sinus tachycardia
Which of the following is INCORRECT
regarding cyclic antidepressant overdose?
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A. a-Adrenoceptor
blockade
B. Anticholinergic effects
C. Calcium channel
blockade
D. Inhibition of reuptake of
serotonin & norepinephrine
E. Sodium channel
blockade
A 17yo F stated that she took an unknown
amount of nortriptyline tabs 2.5 hrs PTA has
endured 6 hrs of ED observation. Which of the
following would prevent her from being medically
cleared for psych?
 A. Absent bowel sounds
 B. Heart rate of 110
 C. QRS duration 88 msec
 D. PR interval of 180
msec
Which of the following statements
regarding tricyclic
antidepressants is INCORRECT?
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A. After a TCA overdose, the onset &
progression of toxicity is rapid
B. Neurologic impairment is rare.
C The development of QRS prolongation is
a sign of serious TCA toxicity
D. Sodium channel blockade can result as
a part of tricyclic overdose.
Which of the following is CORRECT
regarding tricyclic antidepressant
overdose:
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A. CNS depression (disorientation, slurred speech,
coma, respiratory depression), szs, myoclonus
B. Anticholinergic toxicity marked by flushed skin,
tachycardia, mydriasis, decreased bowel sounds,
urinary retention
C. ECG: R > S in aVR
D. All of the statements are true.
Which of the following is INCORRECT
regarding the newer cyclic
antidepressants?
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A. Trazodone (Desyrel): a triazolopyridine with
almost no cardiac toxicity and only CNS
depressive effects without seizures
B. Amoxapine (Asendin): little cardiovascular
toxicity, but high incidence of seizures & death
C. Maprotiline (Ludiomil): a tetracyclic compound
with less cv toxicity but more risk of szs
D. Doxepin: significantly fewer cardiovascular toxic
effects than other tricyclics.
Which of the following is NOT a
pharmacologic effects of the cyclic
antidepressants?
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A. inhibition of norepinephrine, serotonin &
dopamine reuptake in the CNS
B. direct stimulation of anterior horn cells
C. anticholinergic effects and alphaadrenergic blockade
D. quinidine-like membrane-stabilizing
effects.
Which of the following techniques would
FAIL to alkalinize the blood in a cyclic
antidepressant overdose pt?
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A. sodium bicarbonate, 0.5-3 mEq/kg IV
over several minutes, then 2 amps bicarb in
1 L D5W started at 50 mL/hr and titrated to
a pH of 7.5 (7.4 to 7.6).
B. hyperventilation to a pH of 7.5
C. hypoventilation to a pH of 7.5
The first clinical sign of toxicity with
chlorinated hydrocarbon pesticides is:
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A. Allergic manifestations, i.e., lacrimation, rhinitis,
rhinorrhea, sneezing, throat irritation and pharyngeal
& laryngeal edema
B. Chemical burns of the oropharynx soon after
ingestion
C. Hypermetabolic & hyperthermic, i.e., tachycardic,
tachypneic, diaphoretic
D. Neurotoxic symptoms: seizures, confusion,
combativeness, muscle twitching
E. The cholinergic syndrome, SLUDGE (salivation,
lacrimation, urinary incontinence, defecation,
gastroenteritis and emesis)
Management of organophosphate
toxicity includes:
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A. a clinical decision and disposition tree since
there are no definitive lab studies to confirm
suspected exposure
B. Discontinuing use of atropine if marked
tachycardia & mydriasis occurs
C. Prevention of morbidity primarily arising from cv
complications
D. Use of atropine until drying of respiratory
secretions is accomplished
E. Use of pralidoxime only if started within the first 24
hrs after poisoning due to aging of the
organophosphate-acetylcholinesterase complex
Which of the following is CORRECT
regarding clinical features seen in
substituted phenol poisoning?
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A. Allergic manifestations, such as, lacrimation,
rhinitis, rhinorrhea, sneezing, throat irritation and
pharyngeal and laryngeal edema
B. May be implicated by the presence of a strong,
rancid odor on the patient's clothing, breath or even
vomitus
C. Produce a characteristic yellow staining of the skin
or mucous membranes with dermal exposures
D. Selectively concentrates in the lungs because of an
amine uptake mechanism in the alveolar cells leading
to progressive pulmonary injury
E. Skeletal muscle is the target organ for toxicity
leading to diffuse myotonia and muscle fasciculations
A 3-year old M presents new-onset of seizure
activity. You administer benzodiazepines to control
the szs. Blood glucose is normal and after the child
is placed on the monitor, you find that he is actually
in v tach. The mother tells you that she recently
treated all of her children with Lindane that she got
for a scabies infestation. Which of the following is
the most appropriate antiarrhythmic to give?
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A. Lidocaine
B. Magnesium
C. Phenytoin
D. Procainamide
E. Propranolol
Which of the following statements is
INCORRECT regarding the management
of organophosphate/carbamate
poisoning?
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A. All pts exposed to organophosphates or carbamates
should be decontaminated by removal of clothes &
bathing with soap and water
B. Obtain an airway & oxygenate prior to atropine to
minimize the chance of v fib. Tx szs & arrhythmias prn
C. Atropine: 0.02 mg/kg q 5-30 minutes until
atropinization occurs (tachycardia, dryness, mydriasis,
flushing, etc.); massive doses may be required
D. Pralidoxime, 25-50 mg/kg IV over 15-30 min; repeat
in 1-2 hrs, or 0.5g/hr by drip for severe cases.
E. Asymptomatic pts may be observed for 4 hrs then
safely discharged home.
Which of the following statements is
INCORRECT regarding the effects of and
indications for pralidoxime in
organophosphate poisoning?
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A. Inactivates circulating unbonded
organophosphate molecules.
B. Reactivates cholinesterase by cleaving the
organophosphate-cholinesterase chemical bonds.
C. Not indicated in carbamate poisoning, but in
doubtful cases it should be given based on clinical
impression unless and until the precise toxic
substance is known.
D. 2-PAM can be given IV push with little to no
potential toxicity
Signs and symptoms of organophosphate
and carbamate poisoning are due to
stimulation of what 2 systems?
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A. nicotinic, muscarinic
B. muscarinic, serotonergic
C. muscarinic, adrenergic
D. adrenergic; serotonergic
Which of the following statements is
INCORRECT regarding the Intermediate
Syndrome seen with organophosphate
poisoning?
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A. The syndrome is marked by respiratory failure,
bulbar, nuchal & proximal limb muscle weakness
B. Associated w/ exposure to malathion,
parathion, diazinon & dimethoate
C. Occurs 10 days after resolution of the acute
poisoning (cholinergic crisis)
D. Patients diagnosed as having an Intermediate
Syndrome have red blood cell cholinesterase
levels of less than 20%.
THE END