Compound A is reported to have an oral LD50 of 5 mg/kg body weight. Compound B is reported to have
an LD50 of 50 mg/kg body weight. Of the following statements regarding the relative toxicity of these
two compounds, which is TRUE? - correct answersIngestion of low amounts of compound A would be
predicted to cause more deaths than an equal dose of compound B
Which of the following statements best describe the TD50 of a compound? - correct answersThe dosage
of a substance that would be predicted to cause a toxic effect in 50% of the population
Of the following analytic methods, which is most commonly used as the confirmatory method for
identification of drugs of abuse? - correct answersGC with mass spectrometry
A weakly acidic toxin (pka=4.0) that is ingested will: - correct answersBe passively absorbed in the
stomach (pH=3.0)
What is the primary product of methanol metabolism by the ADH and ALDH system? - correct
answersFormic acid
Which of the following statements concerning cyanide toxicity is true? - correct answersInhalation of
smoke from burning plastic is a common cause of cyanide exposure, and cyanide expresses its toxicity by
inhibition of oxidative phosphorylation.
Which of the following laboratory results would be consistent with acute high-level oral exposure to an
inorganic form of mercury (Hg2+)? - correct answers(All): High concentration of mercury in whole blood
and urine, Proteinuria, Positive occult blood in stool.
A child with microcytic, hypo chromic anemia, The physician suspects iron deficiency anemia, Further
Lab tests reveal: normal total serum iron and iron binding capacity, High zinc protoporphyrin. Urinary
screening for porphyrins was positive. Erythrocytic basophilic stippling was noted on peripheral smear.
Which of the following laboratory tests would be best applied to this case? - correct answersWhole
blood lead
A patient with suspected organophosphate poisoning presents with low SChE level. However, the
confirmatory test, erythrocyte acetylcholinesterase presents with a normal result. Excluding analytic
error which of the following may explain these conflicting results? - correct answersThe patient has late
stage hepatic cirrhosis or the patient had a variant of SChE that displays low activity.