Which of the following conditions will increase total T4 by increasing TBG? A. Acute illness B. Anabolic steroid use C. Nephrotic syndrome D. Pregnancy or estrogens

Select the most appropriate single screening test for thyroid disease. A. Free thyroxine index B. Total T3 assay C. Total T4 D. TSH assay

The serum TSH level is almost absent in: A. Primary hyperthyroidism B. Primary hypothyroidism C. Secondary hyperthyroidism D. Euthyroid sick syndrome

Which assay is used to confirm difficult cases of hypothyroidism? A. Free T3 assay B. Free thyroxine index C. Thyrotropin-releasing hormone (TRH) stimulation test D. TBG assay

Which of the following statements is true regarding reverse T3 (rT3)? A. Formed in the blood by degradation of T4 B. Physiologically active, but less than T3 C. Decreased in euthyroid sick syndrome D. Interferes with the measurement of serum T3

A patient has an elevated serum T3 and free T4 and undetectable TSH. What is the most likely cause of these results? A. Primary hyperthyroidism B. Secondary hyperthyroidism C. Euthyroid with increased thyroxine-binding proteins D. Euthyroid sick syndrome

A serum thyroid panel reveals an increase in total T4, normal TSH, and normal free T4. What is the most likely cause of these results? A. Primary hyperthyroidism B. Secondary hyperthyroidism C. Euthyroid with increased thyroxine-binding protein D. Subclinical hypothyroidism

Which statement about TSH and T4 in early pregnancy is correct? A. TSH and thyroid hormones fall B. TSH falls and thyroid hormones rise C. TSH and thyroid hormones both rise D. TSH rises and thyroid hormones fall

In which case might a very low plasma TSH result not correlate with thyroid status? A. Euthyroid sick syndrome B. Congenital hypothyroidism C. When TBG is elevated D. After high-dose corticosteroid treatment

In which of the following cases is qualitative analysis of the drug usually adequate? A. To determine whether the dose of a drug with a low therapeutic index is likely to be toxic B. To determine whether a patient is complying with the physician’s instructions C. To adjust dose if individual differences or disease alter expected response D. To determine whether the patient has been taking amphetamines

The term pharmacokinetics refers to the: A. Relationship between drug dose and the drug blood level B. Concentration of drug at its sites of action C. Relationship between blood concentration and therapeutic response D. The relationship between blood and tissue drug levels

The term pharmacodynamics is an expression of the relationship between: A. Dose and physiological effect B. Drug concentration at target sites and physiological effect C. Time and serum drug concentration D. Blood and tissue drug levels

The study of pharmacogenomics involves which type of testing? A. Family studies to determine the inheritance of drug resistance B. Testing drugs with cell cultures to determine the minimum toxic dosage C. Testing for single nucleotide polymorphisms known to affect drug metabolism D. Comparison of dose-response curves between family members

Select the five pharmacological parameters that determine serum drug concentration. A. Absorption, anabolism, perfusion, bioactivation, excretion B. Liberation, equilibration, biotransformation, reabsorption, elimination C. Liberation, absorption, distribution, metabolism, excretion D. Ingestion, conjugation, integration, metabolism, elimination

Which route of administration is associated with 100% bioavailability? A. Sublingual B. Intramuscular C. Oral D. Intravenous

The phrase “first-pass hepatic metabolism” means that: A. One hundred percent of a drug is excreted by the liver B. All drug is inactivated by hepatic enzymes after one pass through the liver C. Some drug is metabolized from the portal circulation, reducing bioavailability D. The drug must be metabolized in the liver to an active form

Which formula can be used to estimate dosage needed to give a desired steady-state blood level? A. Dose per hour = clearance (milligrams per hour) × average concentration at steady state ÷ f B. Dose per day = fraction absorbed – fraction excreted C. Dose = fraction absorbed × (1/protein-bound fraction) D. Dose per day = half-life × log Vd (volume distribution)

Which statement is true regarding the volume distribution (Vd) of a drug? A. Vd is equal to the peak blood concentration divided by the dose given B. Vd is the theoretical volume in liters into which the drug distributes C. The higher the Vd, the lower the dose needed to reach the desired blood level of drug D. The Vd is the principal determinant of the dosing interval

For drugs with first-order elimination, which statement about drug clearance is true? A. Clearance = elimination rate ÷ serum level B. It is most often performed by the liver C. It is directly related to half-life D. Clearance rate is independent of dose

Which statement about steady-state drug levels is true? A. The absorbed drug must be greater than the amount excreted B. Steady state can be measured after two elimination half-lives C. Constant intravenous infusion will give the same minima and maxima as an oral dose D. Oral dosing intervals give peaks and troughs in the dose-response curve

If too small a peak–trough difference is seen for a drug given orally, then: A. The dose should be decreased B. Time between doses should be decreased C. Dose interval should be increased D. Dose per day and time between doses should be decreased

If the peak level is appropriate but the trough level too low at steady state, then the dose interval should: A. Be lengthened without changing the dose per day B. Be lengthened and dose rate decreased C. Not be changed, but dose per day increased D. Be shortened, but dose per day not changed

If the steady-state drug level is too high, the best course of action is to: A. Decrease the dose B. Decrease the dose interval C. Decrease the dose and decrease the dose interval D. Change the route of administration

When should blood samples for trough drug levels be collected? A. 30 minutes after peak levels B. 45 minutes before the next dose C. 1–2 hours after the last dose D. Immediately before the next dose is given

Blood sample collection time for peak drug levels: A. Varies with the drug, depending on its rate of absorption B. Is independent of drug formulation C. Is independent of the route of administration D. Is 30 minutes after a bolus intravenous injection is completed

Which could account for drug toxicity following a normally prescribed dose? A. Decreased renal clearance caused by kidney disease B. Discontinuance or administration of another drug C. Altered serum protein binding caused by disease D. All of these options

Select the elimination model that best describes most oral drugs. A. One compartment, linear first-order elimination B. Michaelis–Menton or concentration-dependent elimination C. Two compartment with a biphasic elimination curve D. Logarithmic elimination

Drugs rapidly infused intravenously usually follow which elimination model? A. One compartment, first order B. One compartment, logarithmic C. Biphasic or two compartment with serum level rapidly falling in the first phase D. Michaelis–Menton or concentration-dependent elimination

Which fact must be considered when evaluating a patient who displays signs of drug toxicity? A. Drug metabolites (e.g., N-acetylprocainamide) may need to be measured as well as parent drug B. If the concentration of total drug is within therapeutic limits, the concentration of free drug cannot be toxic C. If the drug has a wide therapeutic index, then it will not be toxic D. A drug level cannot be toxic if the trough is within the published therapeutic range

When a therapeutic drug is suspected of causing toxicity, which specimen is the most appropriate for an initial investigation? A. Trough blood sample B. Peak blood sample C. Urine at the time of symptoms D. Gastric fluid at the time of symptoms

For a drug that follows first-order pharmacokinetics, adjustment of dosage to achieve the desired blood level can be made using which formula?

For which drug group are both peak and trough measurements usually required? A. Antiarrhythmics B. Analgesics C. Tricyclic antidepressants D. Aminoglycoside antibiotics

Which of the following statements about TLC for drug screening is true? A. Acidic drugs are extracted in an alkaline nonpolar solvent B. A drug is identified by comparing its Rf value and staining to standards C. Testing must be performed using a urine sample D. Opiates and other alkaloids are extracted at an acid pH

The EMIT for drugs of abuse uses an: A. Antibody conjugated to a drug B. Enzyme conjugated to an antibody C. Enzyme conjugated to a drug D. Antibody bound to a solid phase

Which statement about EMIT is true? A. Enzyme activity is inversely proportional to drug level B. Formation of NADH is monitored at 340 nm C. ALP is the commonly used conjugate D. Assay use is restricted to serum

Which statement regarding cloned enzyme donor immunoassay (CEDIA) is true? A. The enzyme used is glucose-6-phosphate dehydrogenase B. The enzyme donor and acceptor molecules are fragments of β-galactosidase C. Drug concentration is inversely related to fluorescence D. The antibody is covalently linked to the enzyme donor

Which statement is true regarding particle-enhanced turbidimetric inhibition immunoassay methods for therapeutic drugs? A. Drug concentration is proportional to light scatter B. Magnetic separation is needed to remove unbound conjugate C. When particle-bound drug binds to antibody, light scattering is increased D. Two antibodies to the drug are needed

Quantitation of a drug by gas chromatography–mass spectroscopy (GC-MS) is usually performed in which mode? A. Total ion chromatography B. Selective ion monitoring C. Ion subtraction D. Selective reaction monitoring

SITUATION: A urine sample is received in the laboratory with the appropriate custody control form, and a request for drug of abuse screening. Which test result would be cause for rejecting the sample? A. Temperature after collection 95°F B. pH 5.0 C. Specific gravity 1.005 D. Creatinine 5 mg/dL

Which substance has the longest detection time? A. Amphetamines B. Cocaine C. Benzodiazepines D. Marijuana

Which statement about the measurement of carboxyhemoglobin is true? A. Treatment with alkaline dithionite is used to convert carboxyhemoglobin to oxyhemoglobin B. Oxyhemoglobin has no absorbance at 540 nm, but carboxyhemoglobin does C. Bichromatic analysis is required in order to eliminate interference by oxyhemoglobin D. Carboxyhemoglobin can be measured by potentiometry

Which of the following statements about blood alcohol measurement is correct? A. Symptoms of intoxication usually begin when the level exceeds 0.05% w/v B. The skin puncture site should be disinfected with isopropanol C. The reference method is based upon enzymatic oxidation of ethanol by alcohol dehydrogenase D. Gas chromatography methods require extraction of ethanol from serum

Which specimen is the sample of choice for lead screening? A. Whole blood B. Hair C. Serum D. Urine

Which of the following enzymes can be used to measure plasma or serum salicylate? A. Peroxidase B. Salicylate esterase C. Salicylate hydroxylase D. p-Aminosalicylate oxidase

Which of the following tests is least essential to the operation of an emergency department at a general hospital? A. Carboxyhemoglobin B. Osmolality C. Salicylate D. Lead

Which of the following trace elements is considered an essential micronutrient? A. Thallium B. Aluminum C. Mercury D. Selenium

When measuring trace metals in blood other than lead, what type of tube should be used? A. Navy blue top B. Green top C. Purple top D. Red top

Which whole-blood level is suggestive of excessive exposure to lead in children but not adults? A. 4 μg/dL B. 14 μg/dL C. 28 μg/dL D. 32 μg/dL

What are the likely laboratory findings in a person suspected of having Wilson’s disease? A. Blood copper and ceruloplasmin low, urinary copper excretion high B. Blood and urine copper concentration high, ceruloplasmin low C. Blood and urine copper concentration high, ceruloplasmin high D. Blood and urine copper concentration low, ceruloplasmin low

Which of the following tumor markers is classified as a tumor suppressor gene? A. BRCA-1 B. Carcinoembryonic antigen (CEA) C. Human chorionic gonadotropin (hCG) D. Nuclear matrix protein

In general, in which of the following situations is the analysis of a tumor marker most useful? A. Testing for recurrence B. Prognosis C. Screening D. Diagnosis

Which of the following enzymes is increased in persons with prostate and small-cell lung cancer? A. Creatine kinase-1 (CK-1) B. Gamma glutamyl transferase (GGT) C. Amylase D. Lactate dehydrogenase

Which of the following is the best analyte to monitor for recurrence of ovarian cancer? A. CA-15-3 B. CA-19-9 C. CA-125 D. CEA

Which tumor marker is associated with cancer of the urinary bladder? A. CA-19-9 B. CA-72-4 C. Nuclear matrix protein D. Cathepsin-D

A person presents with a cushingoid appearance and an elevated 24-hour urinary cortisol level. The plasma adrenocotropic hormone (ACTH) is very elevated, and the physician suspects the cause is ectopic ACTH production. Which test would be most useful in substantiating this diagnosis? A. Plasma cortisol B. CA-50 C. Alkaline phosphatase isoenzymes D. AFP

Which of the following tumor markers is used to monitor persons with breast cancer for recurrence of disease? A. Cathepsin-D B. CA-15-3 C. Retinoblastoma gene D. Estrogen receptor (ER)

Which of the following statements regarding the Philadelphia chromosome is true? A. It is seen exclusively in chronic myelogenous leukemia B. It results from a translocation C. It appears as a short-arm deletion of chromosome 21 D. It is associated with a poor prognosis

What is the primary clinical utility of measuring CEA? A. Diagnosis of liver cancer B. Diagnosis of colorectal cancer C. Screening for cancers of endodermal origin D. Monitoring for recurrence of cancer

Which tumor marker is used to determine the usefulness of trastuzumab (Herceptin) therapy for breast cancer? A. PR B. CEA C. HER-2/neu D. Myc

A person is suspected of having testicular cancer. Which type of hCG test would be most useful? A. Plasma immunoassay for intact hCG only B. Plasma immunoassay for intact hCG and the β-hCG subunit C. Plasma immunoassay for the free alpha and β-hCG subunits D. Urine assay for hCG β core

A patient treated for a germ cell tumor has a total and free β-hCG assay performed prior to surgery. The result is 40,000 mIU/mL. One week following surgery, the hCG is 5,000 mIU/mL. Chemotherapy is started, and the hCG is measured 1 week later and found to be 10,000 mIU/mL. What does this indicate? A. Recurrence of the tumor B. Falsely increased hCG owing to drug interference with the assay C. Analytical error with the test reported as 5,000 mIU/mL D. Transient hCG increase caused by chemotherapy

Which set of results for ER and PR is associated with the highest likelihood of a favorable response to treatment with estrogen-suppression therapy (tamoxifen)? A. ER positive, PR positive B. ER positive, PR negative C. ER negative, PR positive D. ER negative, PR negative

Which type of cancer is associated with the highest level of AFP? A. Hepatoma B. Ovarian cancer C. Testicular cancer D. Breast cancer

Which of the following assays is recommended as a screening test for colorectal cancer in persons over 50 years old? A. CEA B. AFP C. Occult blood D. Fecal trypsin

Which of the following assays is used to determine the risk of developing cancer? A. Epidermal growth factor receptor (EGF-R) B. Squamous cell carcinoma antigen (SCC) C. c-erb B-2 gene expression D. p53 gene mutation

A person has an elevated 24-hour urinary homovanillic acid (HVA) and vanillymandelic acid (VMA). Urinary metanephrines, chromogranin A, and neuron-specific enolase are also elevated but 5-hydroxyindoleacetic acid is within the reference range. What is the most likely diagnosis? A. Carcinoid tumors of the intestine B. Pheochromocytoma C. Neuroblastoma D. Pancreatic cancer

In which of the following conditions is PSA least likely to be increased? A. Precancerous lesions of the prostate B. Postprostate biopsy C. Benign prostatic hypertrophy D. Post–digital rectal examination

Which of the following statements regarding PSA is true? A. Complexed PSA in plasma is normally less than free PSA B. Free PSA below 25% is associated with malignant disease C. A total PSA below 4 ng/mL rules out malignant disease D. A total PSA above 10 ng/mL is diagnostic of malignant disease

A 55-year-old male with early stage prostate cancer diagnosed by biopsy had his prostate gland removed (simple prostatectomy). His PSA prior to surgery was 10.0 ng/mL. If the surgery was successful in completely removing the tumor cells, what would the PSA result be 1 month after surgery? A. Undetectable B. 1–3 ng/mL C. Less than 4 ng/mL D. Less than 10 ng/mL