Therapeutic Drug Monitoring Vitamins and Nutrition
Which of the following choices is correct when describing the principles of competitive radioimmunoassay procedures?
Antibody will react equally with labeled and unlabeled antigen
A physician needs to prescribe a drug to a patient but the drug has a narrow therapeutic window. He is concerned about possible toxic effects. To assess the upper concentration of such a drug, which time for drawing the specimen do you think makes the most sense?
Approximately one hour after an oral dose
All of the following are therapeutic drugs used to treat cardiac disease, EXCEPT?
Carbamazepine
Tricyclic Antidepressants (TCAs) are used to treat insomnia, depression, extreme apathy, and loss of libido. All of the following are TCAs, EXCEPT?
Clozapine
Which of the following is true of genotype screening in pharmacogenomics?
Genotyping does not take into account drug interactions which can affect metabolism.
What type of anticoagulant is generally suitable for TDM analysis?
Heparin
When considering therapeutic drug monitoring, which two organ systems are associated with drug elimination?
Hepatic and renal
The most common testing method for vitamin E determination is by:
High-performance liquid chromatography (HPLC)
When should blood samples for trough drug levels be collected?
Immediately before the next dose is given
To assess drug concentrations during the trough phase, blood should be drawn:
Immediately before the next dose is given.
Which of the following is the most common technique that is used by clinical laboratories for therapeutic drug monitoring?
Immunoassay
A patient suffering from Celiac disease and Crohn disease (both inflammatory conditions of the GI tract) is given a new oral medication that has a narrow therapeutic window. Which of the following would be true?
Therapeutic drug monitoring (TDM) would be helpful to see how much drug has been absorbed.
The range between a drug's effective dose and its toxic dose is called?
Therapeutic window
A deficiency in which of the folowing vitamins is associated with "Beriberi"?
Thiamine
What are the 3 main effects of active vitamin D on the body?
To absorb calcium and phosphorus in the intestines, from bone, and in the kidneys
Bioavailability of an oral drug refers to the:
Fraction of the drug that is absorbed into systemic circulation
Aminoglycosides can cause severe toxicity including which of the following?
Nephrotoxicity and ototoxicity
Enzyme-multiplied immunoassay techniques (EMIT) differ from all other types of enzyme immunoassays in that:
No separation of bound and free antigen is required
Which of the following is a true statement about aminoglycoside antibiotics?
Aminoglycosides can be toxic antibiotics that are used to treat bacterial infections when such bacteria are resistant to less-toxic antibiotics.
Which medication would be prescribed for narcolepsy?
Amphetamine
Which is the definition of pharmacokinetics?
The study of drug disposition in the body - how and when drugs enter the circulation, how long they stay there, and how they are eliminated.
Toxic levels of lithium can cause lethargy, apathy, muscle weakness up to and including seizures and coma. What is the toxic level of lithium?
1.5-2 mmol/L
What is the half-life of immunosuppressive drugs cyclosporine and tacrolimus?
10-12 hours
What is the half-life for aminoglycoside antibiotics in the blood?
2-3 hours
What is the half-life of digoxin in plasma?
38 hours
Approximately how many doses are required to obtain a steady-state oscillation allowing for peak and trough levels to be evaluated?
5 to 7
How long does it take for plasma concentrations to reach steady state when a patient's dose is given at intervals of the drug's half-life?
5-7 half-lives
When should a peak digoxin level be drawn?
8-10 hours after an oral dose
What type of chemical is lithium?
A cationic metal
Which of the following drug examples would be a good candidate for therapeutic drug monitoring (TDM)?
A drug that has a narrow therapeutic window
A Cytochrome P450 2D6 (CYP2D6) ultrarapid metabolizer (UM) would require ___________ dose of an active drug (non-prodrug) that is metabolized by CYP2D6 than a CYP2D6 extensive metabolizer (EM).
A higher
In therapeutic drug monitoring, a person who is classified as an ultrarapid metabolizer (UM) would need __________ of a drug metabolized by that enzyme.
A higher dose
Cyclosporine and tacrolimus (both immunosuppressive drugs) have multiple therapeutic ranges, why?
Because both drugs have ranges dependent on the organ transplanted and the time after transplantation.
Which disease/condition is associated with a deficiency in thiamine?
Beriberi
To assess drug concentrations during the trough phase:
Blood should be drawnimmediately before the next dose is given.
Which three genetic variations in enzymes are most often linked to differences in drug metabolism?
CYP2D6, CYP2C9 & CYP3A4
A patient in renal failure is seen for blood work. What would you expect the serum calcium and phosphorus levels to be in this patient?
Decreased calcium but increased phosphorus levels
Which of the following drugs is used to treat congestive heart failure?
Digoxin
Which of the following therapeutic drugs increases the force of myocardial muscle contraction?
Digoxin
The amount of time it takes for a drug's concentration in the body to decrease by 50% is referred to as?
Drug half-life
Thin-layer chromatography is particularly useful as a tool in the identification of:
Drugs
What is the mechanism of action for methotrexate?
Inhibits DNA synthesis
A drug that is administered through which of the following routes will reach peak level the quickest?
Intravenous (IV)
Pernicious anemia refers to cobalamin deficiency that results from a lack of which of the following?
Intrinsic Factor
Which of the following is necessary for the absorption of Vitamin B12:
Intrinsic factor
Albuterol is a fast-acting bronchodilator used acutely during asthma attacks. All of the reasons below explain why therapeutic drug monitoring (TDM) for albuterol is not available or common, EXCEPT?
It has a narrow therapeutic window.
If a drug is given at intervals that are the same as its half-life, approximately how long will it take the drug to reach steady state?
It will take about 5-7 half-lives to reach steady state
When is a trough blood sample for therapeutic drug monitoring usually obtained?
Just before the next scheduled dose
Vitamin D is formed in the skin and hydroxylated in two places before it is in its active form of 1,25-dyhydroxy vitamin D. Where does the second hydroxylation occur?
Kidneys
Methotrexate is a highly toxic medication that blocks DNA synthesis in all cells. What medication needs to be administered after methotrexate to prevent cytotoxic effects in normal cells of the body?
Leucovorin
Which medication is primarily used in the treatment of bipolar disorder?
Lithium
Which of the following drugs is used primarily for the treatment of manic-depression?
Lithium
Albumin levels are can be a good gauge for chronic protein deficiency. Which of the following terms describes inadequate protein and caloric intake?
Marasmus
All of the following statements are true regarding the hepatic system and drug metabolism, EXCEPT?
Metabolism of acetaminophen by the MFO system is altered by alcohol and makes it less toxic.
Which of the following medications is considered an antineoplastic drug?
Methotrexate
How is valproic acid (Depakote) administered?
Oral preparation
Vitamin D is controlled by which hormone in a negative feedback loop?
PTH
Which of the following statements regarding peak level in therapeutic drug monitoring is true?
Peak level is assessed by collecting a blood sample after a dose of the drug is given (at a specified time).
Which of the following statements regarding peak level in therapeutic drug monitoring is true?
Peak level is the point at which the drug is highest in the patient's body.
What would the following Schilling test results indicate: Part I: 2% excretion of radioactive vitamin B12 (normal: 5-35%)Part II: 8% excretion of radioactive vitamin B12 after intrinsic factor was given with vitamin B12 (normal: 7-10%).
Pernicious anemia
The study of how variations in the human genome affect a given individual's response to medications is called?
Pharmacogenomics (Pharmacogenetics)
The study of drug disposition in the body - how and when drugs enter the circulation, how long they stay there, and how they are eliminated is called?
Pharmacokinetics
Of the following anticonvulsant medications, which one does not rely soley on the liver to metabolize it for excretion?
Phenobarbital
Of the following, which has the longest half-life?
Phenobarbital
Which of the following drugs is listed as an anti-convulsants?
Phenobarbital
Which of the folloing is the prodrug of phenobarbital?
Primidone
When collecting a specimen for vitamin A, which of the following special precautions needs to be taken?
Protect the specimen from light
Which of the following is considered the major transport protein for vitamin A?
Retinol-binding protein
Which of the following immunosuppressive drugs below has been associated with thrombus formation in patients with toxic levels?
Tacrolimus
The pharmacogenetic profiling reveals a mutation in a CYP450 enzyme that causes increased enzyme activity. Which of the statements below is incorrect?
The CYP450 variants have no influence on drug metabolism.
Which of the following drugs is used to treat asthma and COPD in patients with nocturnal symptoms or problems with inhalers?
Theophylline
Which of the following is a bronchodilator used to treat a 39-year-old male asthmatic patient?
Theophylline
Which of the following conditions would argue in favor of therapeutic drug monitoring (TDM) for a given drug?
The drug is given chronically.
When considering therapeutic drug monitoring (TDM), what is the definition of bioavailability?
The fraction of the administered dose that eventually reaches its site of action
If a disease or disorder causes serum binding proteins (such as albumin) to decrease, what may occur if the dose of a highly protein-bound drug with a narrow therapeutic window is not adjusted?
The patient may experience toxic effects (high free drug fraction).
Which of the following factors would least affect an orally-administered drug's absorption and/or distribution in the body?
The position of the patient when the drug is taken (sitting vs. standing
Which of the following statements regarding trough level in therapeutic drug monitoring is true?
Trough level is assessed by collecting a blood sample right before the next dose of the drug is given.
Regarding therapeutic drug monitoring, which of the following statements is correct when collecting a specimen for a trough level?
Trough level is tested on a blood sample that is collected immediately prior to when the next dose of the drug is given.
Which of the following statements regarding trough level in therapeutic drug monitoring is true?
Trough level is the point at which the drug is lowest in the patient's body.
All of the following are considered aminoglycoside antibiotics, EXCEPT?
Vancomycin
A deficiency in which of the folowing vitamins is associated with "Night Blindness"?
Vitamin A
The deficiency in which fat soluble vitamin is associated with night blindness?
Vitamin A
A deficiency in which of the folowing vitamins is associated with "scurvy"?
Vitamin C
A deficiency in which of the folowing vitamins is associated with "rickets"?
Vitamin D
Which one of the following statements concerning Vitamin D is correct?
Vitamin D acts as a hormone in calcium regulation.
A deficiency in which of these vitamins leads to increased clotting time and may result in hemorrhagic disease?
Vitamin K
The term pharmacokinetics BEST describes:
What the body does to the drug
What type of specimen is used for testing cyclosporine levels?
Whole blood