Standard drug dosing is often based on pharmacokinetic data from average-sized individuals, but this “one-size-fits-all” approach is inadequate for patients with obesity or those who have undergone bariatric surgery. These specialized populations exhibit significant pharmacokinetic changes that alter drug absorption, distribution, and clearance. As detailed in the Patient Care 4 curriculum’s “Transcending Concept” module on “Obesity and Bariatric Surgery Dosing,” pharmacists must be skilled in navigating these complexities to ensure safe and effective therapy. This quiz will test your knowledge on the principles of dose adjustments, formulation selection, and the unique medication-related challenges in these patient groups.
1. In a patient with obesity, the volume of distribution (Vd) for a highly lipophilic drug is expected to be:
- a. Decreased
- b. Increased
- c. Unchanged
- d. Unpredictable
Answer: b. Increased
2. Which weight descriptor is most commonly recommended for dosing highly hydrophilic drugs in patients with obesity?
- a. Total Body Weight (TBW)
- b. Ideal Body Weight (IBW) or Adjusted Body Weight (AdjBW)
- c. Lean Body Weight (LBW)
- d. The weight does not matter.
Answer: b. Ideal Body Weight (IBW) or Adjusted Body Weight (AdjBW)
3. Following a Roux-en-Y gastric bypass (RYGB) surgery, the absorption of many oral drugs is altered due to:
- a. An increase in stomach acidity.
- b. Bypassing primary absorption sites like the duodenum and proximal jejunum.
- c. A larger surface area for absorption.
- d. Slower gastric transit time.
Answer: b. Bypassing primary absorption sites like the duodenum and proximal jejunum.
4. Which of the following dosage forms should generally be AVOIDED in a patient who has recently undergone bariatric surgery?
- a. Immediate-release tablets that can be crushed.
- b. Oral liquids or suspensions.
- c. Extended-release (ER, XL) or enteric-coated (EC) formulations.
- d. Chewable tablets.
Answer: c. Extended-release (ER, XL) or enteric-coated (EC) formulations.
5. Patients who have had a malabsorptive bariatric procedure like RYGB require lifelong supplementation with:
- a. Only fat-soluble vitamins.
- b. A comprehensive regimen of vitamins and minerals, including B12, iron, and calcium.
- c. Only water-soluble vitamins.
- d. No supplements are needed after the first year.
Answer: b. A comprehensive regimen of vitamins and minerals, including B12, iron, and calcium.
6. The lecture “Obesity and Bariatric Surgery Dosing” is a specific “Transcending Concept” in which course?
- a. PHA5784C Patient Care 4
- b. PHA5104 Sterile Compounding
- c. PHA5703 Pharmacy Law and Ethics
- d. PHA5878C Patient Care 3
Answer: a. PHA5784C Patient Care 4
7. Why should NSAIDs be avoided in patients after gastric bypass surgery?
- a. They are not effective for pain in this population.
- b. They significantly increase the risk of gastrointestinal bleeding and ulceration at the surgical anastomoses.
- c. They have altered absorption.
- d. They cause severe constipation.
Answer: b. They significantly increase the risk of gastrointestinal bleeding and ulceration at the surgical anastomoses.
8. For dosing an aminoglycoside in a patient with obesity, which weight is typically used?
- a. Total Body Weight (TBW)
- b. Ideal Body Weight (IBW)
- c. Adjusted Body Weight (AdjBW)
- d. The dosing is fixed for all weights.
Answer: c. Adjusted Body Weight (AdjBW)
9. The increase in cardiac output and renal blood flow in patients with obesity can lead to what pharmacokinetic change?
- a. Decreased clearance of renally eliminated drugs.
- b. Increased clearance of some renally eliminated drugs.
- c. No change in renal clearance.
- d. Decreased volume of distribution.
Answer: b. Increased clearance of some renally eliminated drugs.
10. After a sleeve gastrectomy, the stomach volume is significantly reduced. This most directly affects:
- a. The absorption of drugs in the colon.
- b. The dissolution and absorption of large or slowly dissolving tablets.
- c. The metabolism of drugs by CYP3A4.
- d. The renal excretion of drugs.
Answer: b. The dissolution and absorption of large or slowly dissolving tablets.
11. Considering special patient populations is a key objective in the Principles of Drug Therapy Individualization course.
- a. True
- b. False
Answer: a. True
12. A patient post-RYGB needs to take an oral bisphosphonate for osteoporosis. What is the primary concern?
- a. The risk of esophagitis and poor, unpredictable absorption.
- b. The drug will be too effective.
- c. It will cause severe diarrhea.
- d. There is no concern with this combination.
Answer: a. The risk of esophagitis and poor, unpredictable absorption.
13. A higher loading dose of a hydrophilic drug may be needed in a patient with obesity who also has:
- a. Dehydration
- b. An increased volume of distribution due to an expanded intravascular volume.
- c. Decreased renal function
- d. A very low BMI
Answer: b. An increased volume of distribution due to an expanded intravascular volume.
14. Which formulation is preferred for a patient in the immediate post-operative period after bariatric surgery?
- a. A large extended-release tablet
- a. A liquid, chewable, or crushable immediate-release formulation
- c. An enteric-coated tablet
- d. A hard gelatin capsule
Answer: b. A liquid, chewable, or crushable immediate-release formulation
15. A patient with obesity has a higher percentage of what type of tissue compared to a lean individual?
- a. Muscle tissue
- b. Bone tissue
- c. Adipose tissue
- d. Water
Answer: c. Adipose tissue
16. The change in gastric pH after some bariatric procedures can impair the absorption of drugs that require an acidic environment, such as:
- a. Calcium carbonate
- b. Iron supplements and ketoconazole
- c. Metformin
- d. Omeprazole
Answer: b. Iron supplements and ketoconazole
17. The management of nutrition and weight is a module within the Patient Care 4 curriculum.
- a. True
- b. False
Answer: a. True
18. When dosing low-molecular-weight heparin (LMWH) for VTE treatment in a patient with obesity, what is the current recommendation?
- a. Use a fixed dose regardless of weight.
- b. Dose based on ideal body weight.
- c. Dose based on total body weight, sometimes with dose capping.
- d. LMWH is contraindicated in obesity.
Answer: c. Dose based on total body weight, sometimes with dose capping.
19. Why is lifelong Vitamin B12 supplementation necessary after a gastric bypass?
- a. The surgery increases B12 absorption.
- b. The part of the stomach that produces intrinsic factor, which is necessary for B12 absorption, is bypassed.
- c. All patients are deficient in B12 before surgery.
- d. The surgery causes an increase in stomach acid.
Answer: b. The part of the stomach that produces intrinsic factor, which is necessary for B12 absorption, is bypassed.
20. An active learning session covering bariatric dosing is part of the Patient Care 4 course.
- a. True
- b. False
Answer: a. True
21. A “crush list” or “do-not-crush list” is an essential resource for a pharmacist caring for a patient who:
- a. Has a history of hypertension.
- b. Has undergone bariatric surgery or has an enteral feeding tube.
- c. Is taking more than five medications.
- d. Is over the age of 65.
Answer: b. Has undergone bariatric surgery or has an enteral feeding tube.
22. Which of the following is a key characteristic of lipophilic drugs?
- a. They have a low volume of distribution.
- b. They readily distribute into fatty tissue.
- c. They are primarily cleared by the kidneys unchanged.
- d. They are not affected by obesity.
Answer: b. They readily distribute into fatty tissue.
23. A patient who had a gastric bypass is at higher risk for medication ‘dumping’. This refers to:
- a. The patient throwing their medications away.
- b. A rapid delivery of a drug to the small intestine, potentially causing side effects or altered absorption.
- c. The medication getting stuck in the stomach pouch.
- d. The medication being excreted too quickly by the kidneys.
Answer: b. A rapid delivery of a drug to the small intestine, potentially causing side effects or altered absorption.
24. The pharmacist’s role in the care of a bariatric surgery patient is to:
- a. Perform a pre-operative medication review to identify needed changes.
- b. Counsel on post-operative medication formulations and lifelong supplementation.
- c. Monitor for drug-related problems post-operatively.
- d. All of the above.
Answer: d. All of the above.
25. A patient with obesity has an increased absolute amount of CYP enzymes, but the activity per gram of liver tissue may be reduced due to:
- a. Non-alcoholic fatty liver disease (NAFLD)
- b. Increased renal clearance
- c. Decreased protein binding
- d. Increased cardiac output
Answer: a. Non-alcoholic fatty liver disease (NAFLD)
26. Which of the following is a hydrophilic antibiotic?
- a. Ciprofloxacin
- b. Doxycycline
- c. Gentamicin
- d. Azithromycin
Answer: c. Gentamicin
27. A patient who has had bariatric surgery may need to take which formulation of calcium for optimal absorption?
- a. Calcium carbonate
- b. Calcium citrate
- c. Any form is acceptable.
- d. Calcium phosphate
Answer: b. Calcium citrate
28. What is the most important factor to consider when deciding on a drug and dose for a patient with obesity?
- a. The cost of the medication.
- b. The specific pharmacokinetic properties of the drug (lipophilicity, clearance pathway).
- c. The color of the tablet.
- d. The patient’s preference.
Answer: b. The specific pharmacokinetic properties of the drug (lipophilicity, clearance pathway).
29. A patient is prescribed an extended-release metformin tablet post-gastric bypass. The pharmacist should:
- a. Dispense the medication as written.
- b. Crush the tablet before dispensing.
- c. Contact the prescriber to recommend switching to an immediate-release formulation.
- d. Tell the patient to dissolve the tablet in water.
Answer: c. Contact the prescriber to recommend switching to an immediate-release formulation.
30. The “Specialized Populations: Obesity and Bariatric Dosing” transcending concept is part of which course module?
- a. Module 5: Nutrition & Weight Management
- b. Module 1: PUD and GERD
- c. Module 4: Gastrointestinal Infections
- d. Module 6: Colorectal Cancer
Answer: a. Module 5: Nutrition & Weight Management
31. For a lipophilic drug, using Ideal Body Weight to calculate a dose in a patient with obesity would likely result in:
- a. Supratherapeutic levels and toxicity.
- b. Therapeutic levels.
- c. Subtherapeutic levels and treatment failure.
- d. No change compared to dosing by TBW.
Answer: c. Subtherapeutic levels and treatment failure.
32. The absorption of which type of vitamin is most affected by malabsorptive bariatric procedures?
- a. Water-soluble vitamins
- b. Fat-soluble vitamins (A, D, E, K)
- c. Vitamin C
- d. All vitamins are affected equally.
Answer: b. Fat-soluble vitamins (A, D, E, K)
33. The principles of drug individualization for special populations are covered in the PHA5132 course.
- a. True
- b. False
Answer: a. True
34. Why is it important for a pharmacist to be involved in the care of a patient pre- and post-bariatric surgery?
- a. To manage complex changes in medication regimens and formulations.
- b. To help prevent nutrient deficiencies.
- c. To identify and resolve potential absorption issues.
- d. All of the above.
Answer: d. All of the above.
35. A patient with obesity has a body surface area (BSA) that is:
- a. Smaller than a lean person of the same height.
- b. The same as a lean person of the same height.
- c. Larger than a lean person of the same height.
- d. Not able to be calculated.
Answer: c. Larger than a lean person of the same height.
36. Dosing of some chemotherapy agents is based on BSA. In a patient with obesity, this can lead to:
- a. Underdosing if an ideal BSA is used.
- b. A need to use actual BSA, sometimes with dose capping, to avoid toxicity.
- c. Overdosing if an ideal BSA is used.
- d. Chemotherapy being contraindicated.
Answer: b. A need to use actual BSA, sometimes with dose capping, to avoid toxicity.
37. Which statement best describes the effect of obesity on drug clearance?
- a. It is always increased.
- b. It is always decreased.
- c. The effect is variable and depends on the specific drug and the patient’s organ function.
- d. It is never affected.
Answer: c. The effect is variable and depends on the specific drug and the patient’s organ function.
38. The most reliable way to dose a narrow therapeutic index drug in a patient post-bariatric surgery is to:
- a. Use the standard dose.
- b. Double the standard dose.
- c. Use therapeutic drug monitoring (TDM) if available.
- d. Avoid the drug entirely.
Answer: c. Use therapeutic drug monitoring (TDM) if available.
39. A patient post-bariatric surgery should be counseled that their medication needs may change as they lose weight.
- a. True
- b. False
Answer: a. True
40. An active learning session covering bariatric dosing is part of the Patient Care 4 curriculum.
- a. True
- b. False
Answer: a. True
41. The volume of distribution (Vd) is a key pharmacokinetic parameter because it helps determine the:
- a. Rate of elimination.
- b. Appropriate loading dose.
- c. Half-life.
- d. Rate of absorption.
Answer: b. Appropriate loading dose.
42. For patients with obesity, the glomerular filtration rate (GFR) is often:
- a. Decreased
- b. Unchanged
- c. Increased (augmented renal clearance)
- d. Impossible to measure
Answer: c. Increased (augmented renal clearance)
43. Which of the following is NOT a good reason to consult a pharmacist about dosing in an obese patient?
- a. The drug is lipophilic.
- b. The drug has a narrow therapeutic index.
- c. The drug is commonly dosed using standard doses for all adults.
- d. The patient has comorbid renal or hepatic dysfunction.
Answer: c. The drug is commonly dosed using standard doses for all adults.
44. A patient post-gastric sleeve surgery complains of severe heartburn. The pharmacist should recommend a PPI in which formulation?
- a. An enteric-coated tablet
- b. A large extended-release tablet
- c. A capsule that can be opened or a powder for suspension
- d. A regular hard-pressed tablet
Answer: c. A capsule that can be opened or a powder for suspension
45. Which of the following is a hydrophilic drug whose volume of distribution would NOT be significantly increased in obesity?
- a. Diazepam
- b. Amiodarone
- c. Digoxin
- d. Verapamil
Answer: c. Digoxin
46. The ultimate goal of dose adjustment in specialized populations is to:
- a. Use the most complicated dosing scheme possible.
- b. Achieve a therapeutic exposure similar to that in non-obese or non-surgical patients.
- c. Give the lowest dose possible to save money.
- d. Give the highest dose possible to ensure efficacy.
Answer: b. Achieve a therapeutic exposure similar to that in non-obese or non-surgical patients.
47. A pharmacist should recommend that a patient who has had bariatric surgery has their medication list reviewed:
- a. Only once, immediately after surgery.
- b. Annually.
- c. Regularly, especially if new medications are added or doses are changed.
- d. It is not necessary to review their medications.
Answer: c. Regularly, especially if new medications are added or doses are changed.
48. An active learning session on obesity and bariatric dosing is part of which course?
- a. PHA5784C Patient Care 4
- b. PHA5163L Professional Skills Lab 3
- c. PHA5781 Patient Care I
- d. PHA5782C Patient Care 2
Answer: a. PHA5784C Patient Care 4
49. The term “dumping syndrome” after bariatric surgery refers to:
- a. The rapid passage of hyperosmolar food from the stomach pouch into the small intestine, causing nausea, cramping, and diarrhea.
- b. The patient throwing away their medications.
- c. A side effect of vitamin supplements.
- d. A type of ulcer.
Answer: a. The rapid passage of hyperosmolar food from the stomach pouch into the small intestine, causing nausea, cramping, and diarrhea.
50. The key takeaway for dosing drugs in these specialized populations is that:
- a. Standard dosing from the package insert is always sufficient.
- b. All drugs should be dosed based on total body weight.
- c. A careful consideration of the drug’s properties and the patient’s unique physiology is required.
- d. These patients cannot take oral medications.
Answer: c. A careful consideration of the drug’s properties and the patient’s unique physiology is required.