Quiz 7: Toxicology

Question 1

A salicylate level is performed to detect toxicity caused by ingestion of excess:

(a) Acetaminophen
(b) Aspirin
(c) Ibuprofen
(d) Pseudoephedrine

Answer 1

(b) Aspirin

Question 2

A 3-year-old child was evaluated for abdominal pain and anorexia by a physician. A CBC revealed hemoglobin of 9.8 g/dL (98 g/L) and basophilic stippling of the RBCs. The doctor should order further tests to check for poisoning from:

(a) Arsenic
(b) Iron
(c) Mercury
(d) Lead

Answer 2

(d) Lead

Question 3

A child presents with microcytic, hypochromic anemia. The physician suspects iron deficiency anemia. Further laboratory testing reveals a normal total serum iron and iron-binding capacity; however, the zinc protoporphyrin level was very high. A urinary screen for porphyrins was positive. Erythrocytic basophilic strippling was noted on the peripheral smear. Which of the following laboratory tests would be best applied to this case?

(a) Whole blood lead
(b) Urinary thiocyanate
(c) Carboxygemoglobin
(d) Urinary anabolic steroids

Answer 3

(a) Whole blood lead

Question 4

A patient enters the emergency department in a coma. The physician suspects a drug overdose. Immunoassay screening tests for opiates, barbiturates, benzodiazepines, THC, amphetamines, and PCP were all negative. No ethanol was detected in serum. Can the physician rule out drug overdose as the cause of this coma with these results.

(a) No
(b) Yes
(c) Maybe

Answer 4

(a) No

Question 5

Which of the following statements best describes the TD50 of a compound?

(a) The dosage of a substance that would be predicted to cause a toxic effect in 50% of the population
(b) The dosage of a substance that is lethal to 50% of the population
(c) The dosage of a substance that would produce therapeutic benefit in 50% of the population
(d) The percentage of individuals who would experience a toxic response at 50% of the lethal dose
(e) The percentage of the population who would experience a toxic response after an oral dosage of 50mg

Answer 5

(a) The dosage of a substance that would be predicted to cause a toxic effect in 50% of the population

Question 6

Of the following analytic methods, which is most commonly used as the confirmatory method for identification of drugs of abuse?

(a) GC with mass spectrometry
(b) Immunoassay
(c) Ion-specific electrode
(d) Nephelometry

Answer 6

(a) GC with mass spectrometry

Question 7

In which of the following cases is qualitative analysis of the drug usually adequate?

(a) To adjust dose if individual differences or disease alter expected response
(b) To determine whether the dose of a drug with a low therapeutic index is likely to be toxic
(c) To determine wether a patient is complying with the physician’s instructions
(d) To determine whether the patient has been taking an unprescribed drug, such as amphetamines

Answer 7

(d) To determine whether the patient has been taking an unprescribed drug, such as amphetamines

Question 8

What is the primary product of methanol metabolism by the ADH and ALDH system?

(a) Formic acid
(b) Acetone
(c) Acetaldehyde
(d) Oxalic acid

Answer 8

(a) Formic acid

Question 9

Identification of the urinary metabolite benzoylecgonine would be useful in determining exposure to which of the following drugs?

(a) Codeine
(b) Cocaine
(c) Amphetamine
(d) Propoxyphene

Answer 9

(b) Cocaine

Question 10

Acetaminophen is particularly toxic to what organ?

(a) Heart
(b) Kidney
(c) Spleen
(d) Liver

Answer 10

(d) Liver

Question 11

Which substance has the longest detection time in urine?

(a) Amphetamines
(b) Benzodiazepines
(c) Cocaine
(d) Marijuana/Cannabinoids

Answer 11

(d) Marijuana/Cannabinoids

Question 12

A urine sample is received in the laboratory with the appropriate custody control form and a request for DOA (drug abuse use) screening. Which test result would be cause for rejecting the sample?

(a) Creatinine 5mg/dL
(b) pH 5.0
(c) Specific gravity 1.013
(d) Temperature after collection is 95 degrees F

Answer 12

(a) Creatinine 5mg/dL

Question 13

The enzyme-multipled immunoassay technique (EMIT) for DOA (drugs of abuse) uses an:

(a) Antibody bound to a solid phase
(b) Antibody conjugated to a drug
(c) Enzyme conjugated to an antibody
(d) Enzyme conjugated to a drug

Answer 13

(c) Enzyme conjugated to an antibody

Question 14

Which of the following urine samples should be accepted for testing when processing samples for drugs of abuse (DOA)?

(a) Container with seal not applied across the lid
(b) Sample with a volume of 50 mL
(c) Urine of abnormal color
(d) Urine with an abnormal odor

Answer 14

(b) Sample with a volume of 50 mL

Question 15

When collecting a serum or whole blood (NaFl tube) specimen sample for alcohol the following should be remembered:

(a) An alcohol prep should not be used to clean the skin before the phlebotomy
(b) Students should not draw legal alcohols
(c) Phlebotomists may or may not be able to draw legal alcohols depending on state law
(d) All of the above are true

Answer 15

(d) All of the above are true

Question 16

Therapeutic drug abuse includes:

(a) Acetaminophen, salicylate
(b) Amphetamines, anabolic steroids
(c) Arsenic, cadmium, lead, mercury
(d) Cyanide, pesticides

Answer 16

(a) Acetaminophen, salicylate

Question 17

Which of the following are true about toxic alcohol poisoning?

(a) A blood level of 0.08-0.1 g/dL is defined in the US as intoxication
(b) A blood level of 80-100 mg/dL is defined in the US as intoxication
(c) 0.2-0.3 g/dL blood alcohol will result in confusion, 0.3-0.4 g/dL stupor, and >0.4 g/dL coma and death
(d) All of the above are true

Answer 17

(d) All of the above are true

Question 18

To differentiate ethanol, methanol, isopropanol, and ethylene glycol from each other, which of the following is true?

(a) Enzymatic methods are the reference methods
(b) Gas chromatography is the reference method and can quantitate the alcohols
(c) The osmolal gap can differentiate all the alcohols
(d) All of the above are true

Answer 18

(b) Gas chromatography is the reference method and can quantitate the alcohols

Question 19

Which of the following are true about the salicylates?

(a) Method of analysis: Trinder colorimetric method, salicylate + ferric iron = red color and read at 540 nm
(b) Signs of toxicity: >90 mg/dL
(c) Stimulates breathing so respiratory alkalosis, then conversion of pyruvate to lactate, resulting in metabolic acidosis, then to respiratory acidosis due to later CNS depression
(d) All of the above

Answer 19

(d) All of the above

Question 20

Which are true about cannabinoids?

(a) The major active cannabinoid is delta-9-tetrahydrocannabinol (THC)
(b) Signs of toxicity include: delusions, paranoia, tachycardia, hypotension
(c) Methods of analysis include: urine immunoassays
(d) All of the above are true

Answer 20

(d) All of the above are true