CHEM07 - TDM and Toxicology

  1. Acetaminophen toxicity will manifest primarily as

    B)  liver failure.
  2. The theophylline analog that may be monitored in the treatment of neonatal apnea is

    C)  caffeine
  3. A patient who overdosed on digoxin was given Digibind. The physician ordered a stat digoxin level 1 hour later. Which of the following is the most appropriate response?

    B)  inform the physician that a digoxin concentration cannot be accurately determined.
  4. The blood concentration of the drug reflects its concentration at its target receptor:

    1. Immediately after ingestion/infusion
    2. At least two hours after ingestion/infusion
    3. After distribution is complete.
    4. Just before the next dose

    F) 1 and 4
  5. The site in the body where most drug metabolism occurs is the

    D) liver
  6. The best time to collect a sample for therapeutic monitoring of most oral drugs is

    D)  immediately before the next dose.
  7. For which of the following metals should all children be tested by age 6?

    A) lead
  8. As a rule of thumb, the steady state concentration of a drug is achieved after how many half lives?

    D) 4-5
  9. The specimen of choice for monitoring levels of the immunosuppressant drugs cyclosporine, tacrolimus andsirolimus is

    A)  whole blood
  10. A drug known to increase the metabolism of many other drugs is

    B)  phenobarbital
  11. The fraction of a dose that reaches the bloodstream is known as a drug's

    C)  bioavailability.
  12. The halflifeof a drug is 4 hours. If the initial concentration is 100 mcg/mL, in three halflivesthe expected drug concentration would be

    D) 13 ug/mL
  13. When testing for therapeutic drugs, steady state refers to

    A)  the time when net drug administered is equal to net drug eliminated
  14. The legal limit for ethanol (ETOH) while driving in California is

    F)  0.08% in whole blood.
  15. The metabolite THCCOOHcan be detected by immunoassay for several days after the use of

    D)  marijuana.
  16. The most sensitive and specific method for identifying drugs of abuse is

    C)  GC mass spectrometry (GCMS).
  17. When receiving a assay request for the drug on the left, which drug on the right should also be measured?


    -No other drug need be measured
    • Getamicin: No other drug need be measured
    • Primidone: Phenobarbital
    • Procainamide: NAPA
  18. What is occurring in phase I metabolism of a therapeutic drug?

    B)  Chemical modification such as hydrolysis or oxidation
  19. The group of enzymes that are particularly involved in phase I metabolism of drugs is

    B)  cytochrome P450.
  20. All of the following are antiepileptic (anticonvulsant) drugs EXCEPT

    C)  procainamide.
  21. The drug most suited for measurement of the free fraction in appropriate circumstances is

    B)  phenytoin.
  22. The most common method of measuring ethanol in clinical laboratories is

    D) enzymatic assay using ADH.
  23. A 56 y.o. female patient has a digoxin measured stat just prior to his 11:00 am doctor's appointment. The result is 6.2 ng/mL (ther. range 0.82.0)and when you call this critical value, the physician responds that the patient is only taking a very low dose every morning and the EKG he just took shows no signs of digoxin toxicity. What is the most likely cause of this discrepancy?

    B)  incomplete distribution
  24. A mass spectrum is a plot of

    A)  m/z vs abundance
  25. A homeless man is taken to the ED with profound "inebriation", hyperventilation and a fruity odor on his breath. Stat glucose is 176 mg/dL and BHB (beta hydroxybutyrate)is normal. Urinalysis is normal except for trace glucose and 1+ ketones. Osmolal gap is elevated. Which test would you recommend to a physician?

    B)  Serum volatiles
  26. Ethylene glycol ingestion might be accompanied by all of the following EXCEPT

    B)  elevated acetone.
  27. The following drugs all have somewhat specific "antidotes" that can minimize toxicity EXCEPT

    A)  ethanol.
  28. You are called to court to testify about a sample drawn in the ED from a driver involved in a collision. The serum alcohol was 86 mg/dL. The prosecution says this proves the driver was legally drunk. The defense counters with one of the following arguments. Which is the most defensible from a laboratory point of view?

    A)  The sample tested was serum, so the results do not correspond to legal definitions of DUI.
  29. Doubling the dose of a drug that follows "saturation" kinetics might lead to

    D)  a quadrupling of steady state drug levels.
  30. A concurrently administered drug that might affect drug levels of gentamicin is

    A)  carbenicillin.
  31. A potential interferent in digoxin immunoassays in pregnant women and newborns is

    D)  DLIS
  32. The drug whose dosing would most likely need adjustment in a patient with renal disease is

    C)  gentamicin.
  33. +Methemoglobin
    +Methemoglobin samples
    +Carboxyhemoglobin samples

    -is hemoglobin with Fe3+.
    -is hemoglobin complexed with carbon dioxide.
    -is hemoglobin complexed with carbon monoxide.
    -are unstable and should be iced or analyzed w/in 30 minutes.
    -are unstable and should be iced
    -must be collected anaerobically.
    -are stable and can be analyzed rou栱nely.
    • Methemoglobin: is hemoglobin with Fe3+.
    • Methemoglobin samples: are unstable and should be iced or analyzed w/in 30 minutes.
    • Carboxyhemoglobin: is hemoglobin complexed with carbon monoxide.
    • Carboxyhemoglobin samples: are stable and can be analyzed routinely.
  34. are stable and can be analyzed routinely.

    B)  CO binds to the O2 binding site, preventing O2 binding.
  35. Proper interpretation of serum acetaminophen levels and hepatic necrosis risk require that the sample be drawn

    D)  no sooner than four hours after ingestion
  36. Definition of a therapeutic range by a laboratory

    A)  uses data from clinical trials
  37. Match the following:

    +what the body does to a drug
    +what a drug does to the body

    • what the body does to a drug: pharmacokinetics
    • what a drug does to the body: pharmacodynamics
  38. The type of drug administration that shows the MOST variability among patients is:

    A)  oral
  39. The drug mentioned in class as a potential candidate for dosing decisions made on pharmacogenetics is

    D)  warfarin
  40. The drug for which peak levels would be most useful is

    B)  vancomycin
  41. Monitoring of which of the following psychotropic drugs (or drug classes) is most appropriate and common.

    B)  lithium
  42. Iron was recommended to be available stat, ideally with TIBC. Which of the following results would be the most concerning in a presumed iron ingestion (all units are mcg/dL)?

    E)  Fe 300, TIBC 250
  43. Determination of carboxyhemoglobin in the clinical laboratory would be most commonly performed in which lab section?

    B)  blood gases
  44. For the following ingestions, what compound would provide the most concerning toxicity?

    +ethylene glycol

    -methyl formate
    -oxalic acid
    • ethanol: ethanol
    • ethylene glycol: oxalic acid
    • isopropanol: isopropanol
    • methanol: formaldehyde
  45. Ingestion of poppy seed bagels might give a positive immunoassay reaction for urinary

    D)  opiates
  46. Most reference laboratories require that samples for TDM NOT be collected in

    C)  gel barrier tubes
Card Set
CHEM07 - TDM and Toxicology
CHEM07 - TDM and Toxicology