Dental MCQ
Filtration and drug clearance · Renal & GI · INBDE Patient Cases

Nephron Function INBDE Patient Cases

By Dr. Isaac Sun, DDS

8 ADA INBDE-format patient cases on nephron function. Each case is a shared patient box (chief complaint, history, medications, allergies, exam) followed by linked multiple-choice questions with full distractor explanations. Practice the way the real exam is structured.

8 patient cases40 linked questionsADA INBDE formatFull distractor explanations

Eight ADA INBDE-format patient cases on nephron function and renal physiology in the dental setting: choosing acetaminophen over NSAIDs for a chronic kidney disease patient because NSAIDs constrict the afferent arteriole and lower GFR, scheduling an extraction for a hemodialysis patient the day after dialysis while protecting the arteriovenous fistula and anticipating uremic platelet dysfunction, ACE inhibitor-induced angioedema of the lip and tongue from bradykinin accumulation, thiazide-induced hypokalemia and the arrhythmia risk of epinephrine, spironolactone-related hyperkalemia and the spironolactone plus ACE inhibitor plus NSAID drug stack, cyclosporine-induced gingival overgrowth after kidney transplantation, renal osteodystrophy and secondary hyperparathyroidism with loss of the lamina dura and a brown tumor on a panoramic radiograph, and nephrotic syndrome with low serum albumin, periorbital edema, and altered drug protein binding. Topics include glomerular filtration, the renin-angiotensin-aldosterone system, diuretic sites of action, erythropoietin, calcitriol, and renal drug clearance.

Case Coverage Map
What each case is testing
Which painkiller after an extraction in kidney disease:
NSAID avoidance in CKD, the afferent arteriole and GFR, acetaminophen as first-line, and renal dose adjustment.
On dialysis and needs a tooth out:
Hemodialysis scheduling, heparin and uremic bleeding, protecting the AV fistula arm, and analgesic choice.
Lip and tongue swelled up overnight:
ACE inhibitor angioedema, the bradykinin mechanism, distinguishing it from allergy, and airway-aware referral.
Palpitations and cramps on a water pill:
Thiazide hypokalemia, the arrhythmia risk with epinephrine, ECG changes, and limiting the epinephrine dose.
Wants ibuprofen while on a heart-failure pill:
Spironolactone and hyperkalemia, aldosterone antagonism, NSAID avoidance, and the high-risk drug stack.
Gums growing over the front teeth after a transplant:
Cyclosporine gingival overgrowth, the role of plaque, immunosuppression and infection risk, and the calcium channel blocker parallel.
Routine X-ray with unusual jaw bone:
Renal osteodystrophy on a panoramic film, secondary hyperparathyroidism, loss of lamina dura, and the brown tumor.
Puffy face and frothy urine:
Nephrotic edema and low albumin, glomerular protein loss, altered drug protein binding, and infection risk.
Patient case: Which painkiller after an extraction in kidney disease
0 of 5 answered, 0 correct
Patient
Male, 62 years old
Chief Complaint
"My kidney doctor told me to be careful with painkillers," he says before the extraction.
Background and/or Patient History
  • Presented for extraction of non-restorable tooth #30
  • Stage 3 chronic kidney disease (eGFR about 40 mL/min)
  • Type 2 diabetes and hypertension
  • Takes over-the-counter ibuprofen most days for knee pain
Allergies
NKDA
Medications
  • Lisinopril
  • Metformin
  • Ibuprofen as needed
Current Findings
  • BP 138/86
  • Tooth #30 non-restorable, no swelling or fever
  • No signs of acute infection
  1. Question 1
    Moderate
    Why are NSAIDs generally avoided for pain control in this patient?
  2. Question 2
    Easy
    The most appropriate analgesic for this patient is:
  3. Question 3
    Hard
    His home combination of an ACE inhibitor plus daily ibuprofen is risky because together they can:
  4. Question 4
    Moderate
    If amoxicillin is needed for this patient, the dose should be:
  5. Question 5
    Moderate
    Which home behavior most threatens his kidneys around the time of an extraction?

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Patient case: On dialysis and needs a tooth out
0 of 5 answered, 0 correct
Patient
Male, 55 years old
Chief Complaint
"I'm on dialysis and this back tooth is killing me."
Background and/or Patient History
  • End-stage renal disease on hemodialysis Monday, Wednesday, and Friday
  • Arteriovenous fistula in the left forearm
  • Painful tooth #19 with a localized abscess needing extraction
Allergies
NKDA
Medications
  • Antihypertensives
  • Phosphate binder
  • Heparin during each dialysis session
Current Findings
  • Palpable thrill over the left-forearm fistula
  • BP 142/88
  • Tooth #19 with periapical abscess, no spreading swelling
  1. Question 1
    Moderate
    The best time to schedule his extraction is:
  2. Question 2
    Easy
    Treating him on a dialysis day raises bleeding risk mainly because of:
  3. Question 3
    Moderate
    When taking blood pressure and planning venipuncture, you should:
  4. Question 4
    Moderate
    Even on a non-dialysis day, he may bleed more than expected because uremia causes:
  5. Question 5
    Easy
    For post-extraction pain, the safest choice for this patient is:

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Patient case: Lip and tongue swelled up overnight
0 of 5 answered, 0 correct
Patient
Female, 58 years old
Chief Complaint
"My lower lip and tongue swelled up overnight and it won't go down."
Background and/or Patient History
  • Presented urgently with facial swelling
  • Started lisinopril for blood pressure about three weeks ago
  • No new foods, no insect bites, no itching
  • No rash or hives
Allergies
NKDA
Medications
  • Lisinopril
  • Hydrochlorothiazide
Current Findings
  • Diffuse, non-tender, non-pitting swelling of the lower lip and tongue
  • No urticaria
  • Breathing comfortably, no stridor or wheeze
  • No carious or abscessed teeth, no intraoral swelling source
  1. Question 1
    Moderate
    The most likely cause of her swelling is:
  2. Question 2
    Hard
    The swelling is mediated mainly by accumulation of:
  3. Question 3
    Moderate
    Which feature best distinguishes this from an allergic (histamine) reaction?
  4. Question 4
    Moderate
    The most appropriate action in the dental office is to:
  5. Question 5
    Easy
    The most dangerous potential progression of this condition is:

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Patient case: Palpitations and cramps on a water pill
0 of 5 answered, 0 correct
Patient
Female, 67 years old
Chief Complaint
"My heart sometimes flutters, and my legs cramp a lot."
Background and/or Patient History
  • Presented for extraction of tooth #4
  • Hypertension treated with hydrochlorothiazide for years
  • Reports occasional palpitations and muscle cramps
  • Recent blood test showed a low potassium level
Allergies
NKDA
Medications
  • Hydrochlorothiazide
Current Findings
  • BP 134/82
  • Occasional irregular beats noted at the wrist
  • Tooth #4 non-restorable
  1. Question 1
    Easy
    Her cramps and low potassium are most likely caused by:
  2. Question 2
    Hard
    Why does her hypokalemia raise concern about epinephrine in local anesthetic?
  3. Question 3
    Moderate
    The safest local anesthetic approach is to:
  4. Question 4
    Moderate
    Which ECG change is classically associated with hypokalemia?
  5. Question 5
    Hard
    If a second blood-pressure drug were added, which would most worsen her potassium loss?

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Patient case: Wants ibuprofen while on a heart-failure pill
0 of 5 answered, 0 correct
Patient
Male, 70 years old
Chief Complaint
"I'd like something strong for the pain after you pull this tooth."
Background and/or Patient History
  • Presented for extraction of tooth #14
  • Heart failure treated with spironolactone and lisinopril
  • Plans to buy ibuprofen for post-op pain
  • No chest pain or shortness of breath today
Allergies
NKDA
Medications
  • Spironolactone
  • Lisinopril
Current Findings
  • BP 128/78
  • Tooth #14 non-restorable
  • No acute infection
  1. Question 1
    Easy
    Spironolactone affects his potassium by causing:
  2. Question 2
    Moderate
    Spironolactone works by:
  3. Question 3
    Moderate
    Which post-operative analgesic should you steer him away from?
  4. Question 4
    Easy
    Severe hyperkalemia is dangerous mainly because it can cause:
  5. Question 5
    Hard
    Which combination puts him at the highest risk of hyperkalemia?

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Patient case: Gums growing over the front teeth after a transplant
0 of 5 answered, 0 correct
Patient
Male, 40 years old
Chief Complaint
"My gums are growing over my front teeth."
Background and/or Patient History
  • Kidney transplant two years ago, functioning well
  • Takes cyclosporine and prednisone to prevent rejection
  • Reports difficulty keeping the front teeth clean
  • No pain
Allergies
NKDA
Medications
  • Cyclosporine
  • Prednisone
  • Antihypertensive
Current Findings
  • Generalized firm gingival enlargement, heaviest on the anterior facial gingiva
  • Abundant plaque and calculus
  • No mobility, no abscess
  1. Question 1
    Moderate
    The most likely cause of the gingival enlargement is:
  2. Question 2
    Moderate
    The severity of the overgrowth is most worsened by:
  3. Question 3
    Moderate
    Because of his immunosuppression, you should be especially aware of his increased risk of:
  4. Question 4
    Moderate
    The most appropriate first-line management of the overgrowth is:
  5. Question 5
    Moderate
    Which other medication class causes the same gingival overgrowth?

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Patient case: Routine X-ray with unusual jaw bone
0 of 5 answered, 0 correct
Patient
Female, 52 years old
Chief Complaint
"I'm a new patient and just need a checkup."
Background and/or Patient History
  • Long-standing chronic kidney disease, on dialysis for several years
  • No dental pain
  • Brought for a routine new-patient examination and panoramic radiograph
Allergies
NKDA
Medications
  • Phosphate binder
  • Active vitamin D analog
  • Antihypertensives
Current Findings
  • Panoramic radiograph shows generalized loss of the lamina dura
  • Ground-glass trabecular pattern
  • A well-defined radiolucency in the posterior mandible
  • No carious lesions explaining the findings
  1. Question 1
    Hard
    The generalized loss of lamina dura and ground-glass bone most likely reflect:
  2. Question 2
    Hard
    The underlying mechanism is high parathyroid hormone driven by:
  3. Question 3
    Moderate
    Loss of the lamina dura on the radiograph indicates:
  4. Question 4
    Hard
    The well-defined mandibular radiolucency is most consistent with a:
  5. Question 5
    Moderate
    The most appropriate dental response is to:

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Patient case: Puffy face and frothy urine
0 of 5 answered, 0 correct
Patient
Male, 35 years old
Chief Complaint
"My face is puffy, especially around my eyes in the morning."
Background and/or Patient History
  • Presented for restorative care
  • Diagnosed with nephrotic syndrome
  • Reports frothy urine and recent weight gain from swelling
  • No facial pain or dental swelling source
Allergies
NKDA
Medications
  • Diuretic
  • ACE inhibitor
Current Findings
  • Periorbital and facial puffiness, pitting over the shins
  • No tender tooth or intraoral swelling
  • BP 132/84
  • Blood work notes low serum albumin and heavy proteinuria
  1. Question 1
    Moderate
    His facial and leg swelling is best explained by:
  2. Question 2
    Moderate
    The heavy proteinuria points to damage at the:
  3. Question 3
    Hard
    His low albumin can change drug handling by:
  4. Question 4
    Moderate
    Which feature best separates his swelling from ACE inhibitor angioedema?
  5. Question 5
    Hard
    Patients with nephrotic syndrome are also more prone to infection because they lose:

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Nephron Function core recall

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