1. A 67-year-old man with type 2 diabetes and reduced-ejection-fraction heart failure was started on pioglitazone 30 mg daily six weeks ago. He now presents with a 4 kg weight gain, new bilateral lower-extremity edema, and worsening exertional dyspnea. His glucose control has improved. What is the most appropriate next step?
A) Continue pioglitazone and add a thiazide diuretic, since the edema is unrelated to the drug
B) Increase the pioglitazone dose, because the symptoms indicate inadequate glycemic effect
C) Discontinue pioglitazone, because thiazolidinedione-induced sodium and fluid retention is worsening his heart failure
D) Continue pioglitazone unchanged and attribute the findings solely to dietary sodium
E) Switch pioglitazone to rosiglitazone, which does not cause fluid retention
ANSWER: C
Rationale:
This patient has decompensating heart failure driven by thiazolidinedione (TZD) fluid retention: PPAR-gamma (peroxisome proliferator-activated receptor gamma)-mediated upregulation of the epithelial sodium channel (ENaC) in the collecting duct expands extracellular volume, producing weight gain, edema, and worsening dyspnea. In a patient with reduced-ejection-fraction heart failure, the correct action is to discontinue the TZD.
Option A: Option A is incorrect because the edema is a direct drug effect, and continuing the TZD while masking it with a diuretic does not address the underlying volume expansion in a heart-failure patient.
Option B: Option B is incorrect because improved glucose control plus volume signs indicate fluid retention, not inadequate efficacy, so increasing the dose would worsen the problem.
Option D: Option D is incorrect because attributing the picture solely to diet ignores the clear temporal link to TZD initiation.
Option E: Option E is incorrect because fluid retention is a class effect of TZDs; rosiglitazone shares it and also has an unfavorable cardiovascular profile.
2. An 82-year-old woman with type 2 diabetes, stage 4 chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] 24 mL/min/1.73m2), and a history of two falls in the past year remains above her HbA1c goal on metformin. She has no heart failure or atherosclerotic cardiovascular disease. Which add-on agent best fits her clinical situation?
A) Linagliptin, because it requires no renal dose adjustment and carries low hypoglycemia risk
B) Glipizide, because sulfonylureas are ideal in advanced CKD
C) Pioglitazone, because fracture risk is irrelevant at her age
D) Acarbose, because it is the preferred agent in stage 4 CKD
E) Saxagliptin at full dose, because gliptins need no renal adjustment
ANSWER: A
Rationale:
In an elderly faller with advanced CKD and no heart failure or atherosclerotic disease, hypoglycemia avoidance and renal-appropriate dosing dominate. Linagliptin is eliminated by the biliary/fecal route and requires no renal dose adjustment at any eGFR, and as a DPP-4 (dipeptidyl peptidase-4) inhibitor it carries low hypoglycemia risk, making it the best fit.
Option B: Option B is incorrect because sulfonylureas drive non-glucose-dependent insulin secretion and raise hypoglycemia and fall risk, which is hazardous here.
Option C: Option C is incorrect because pioglitazone adds fracture and fluid-retention risk that are poorly suited to an elderly faller, so fracture risk is highly relevant.
Option D: Option D is incorrect because acarbose is contraindicated in significant renal impairment due to metabolite accumulation, so it is not preferred in stage 4 CKD.
Option E: Option E is incorrect because saxagliptin is renally excreted and requires dose reduction at low eGFR, so full-dose use is inappropriate.
3. A 71-year-old man with type 2 diabetes and a documented history of heart failure is currently taking saxagliptin as part of his regimen. During medication review, his clinician wants to optimize his DPP-4 (dipeptidyl peptidase-4) inhibitor choice for cardiac safety. What is the most appropriate change?
A) Continue saxagliptin, since all gliptins are equivalent for heart failure safety
B) Switch saxagliptin to alogliptin, which has the most reassuring heart failure data
C) Discontinue all gliptins permanently, since the class is contraindicated in heart failure
D) Continue saxagliptin but double the dose to improve cardiac outcomes
E) Switch saxagliptin to sitagliptin or linagliptin, which did not show an excess heart failure hospitalization signal
ANSWER: E
Rationale:
The heart failure hospitalization signal among gliptins is agent-specific: saxagliptin increased heart failure hospitalization in its cardiovascular outcome trial and alogliptin showed a directionally similar signal, whereas sitagliptin and linagliptin did not. In a patient with established heart failure, switching saxagliptin to sitagliptin or linagliptin is appropriate.
Option A: Option A is incorrect because the gliptins are not equivalent for heart failure safety; the risk is concentrated in saxagliptin and alogliptin.
Option B: Option B is incorrect because alogliptin carries a directionally similar signal, not the most reassuring data.
Option C: Option C is incorrect because the class as a whole is not contraindicated in heart failure; sitagliptin and linagliptin are acceptable alternatives.
Option D: Option D is incorrect because increasing the saxagliptin dose would not improve cardiac outcomes and could heighten concern in a heart-failure patient.
4. A 63-year-old postmenopausal woman with type 2 diabetes has a prior distal radius fragility fracture and documented osteoporosis. Her clinician is considering pioglitazone to improve glycemic control. What is the best assessment of this plan?
A) Pioglitazone is ideal here because thiazolidinediones increase bone mineral density
B) Pioglitazone should be avoided because thiazolidinediones increase fracture risk, particularly at distal sites in postmenopausal women, and an alternative agent is preferable
C) Pioglitazone is acceptable without concern, since fracture risk applies only to men
D) Pioglitazone is safe provided the dose is kept low, which eliminates the fracture risk entirely
E) Pioglitazone is preferred over all alternatives specifically because of its skeletal benefits
ANSWER: B
Rationale:
Thiazolidinediones (TZDs) increase fracture risk as a class effect, with the clearest excess at distal extremity sites (wrist, foot, ankle) in postmenopausal women, mediated by PPAR-gamma (peroxisome proliferator-activated receptor gamma)-driven suppression of osteoblast differentiation and increased bone resorption. In a postmenopausal woman with osteoporosis and a prior fragility fracture, pioglitazone should be avoided in favor of an alternative agent.
Option A: Option A is incorrect because TZDs reduce, not increase, bone mineral density.
Option C: Option C is incorrect because postmenopausal women carry the clearest fracture excess, so the risk is highly relevant to her.
Option D: Option D is incorrect because low dosing does not eliminate the fracture liability.
Option E: Option E is incorrect because TZDs harm rather than benefit the skeleton, so skeletal benefit cannot justify selecting it.
5. A 58-year-old woman takes acarbose and glipizide for type 2 diabetes. She develops sweating, tremor, and a capillary glucose of 52 mg/dL. She eats two pieces of hard candy (sucrose), but her symptoms and glucose fail to improve over the next 15 minutes. What is the most appropriate treatment?
A) Give a second, larger serving of sucrose-containing candy
B) Give a starch-based snack such as crackers
C) Reassure her that no treatment is needed since acarbose prevents true hypoglycemia
D) Give oral glucose tablets or gel, because acarbose blocks sucrose hydrolysis and only glucose will be absorbed quickly enough
E) Withhold the next acarbose dose and wait for spontaneous recovery
ANSWER: D
Rationale:
This patient has sulfonylurea-related hypoglycemia while on acarbose, which competitively inhibits brush-border alpha-glucosidases and blocks the hydrolysis of sucrose into absorbable monosaccharides; sucrose therefore fails to correct the episode, which is exactly what happened. The correct treatment is oral glucose (tablets or gel), which is absorbed directly without alpha-glucosidase digestion.
Option A: Option A is incorrect because more sucrose will still be poorly absorbed and will not correct the hypoglycemia.
Option B: Option B is incorrect because starch also requires alpha-glucosidase digestion that acarbose blocks, so it will not act quickly.
Option C: Option C is incorrect because adding glipizide, a sulfonylurea, makes genuine hypoglycemia possible and this episode requires treatment.
Option E: Option E is incorrect because active, symptomatic hypoglycemia requires prompt glucose administration, not passive waiting.
6. A 54-year-old insulin-resistant man with type 2 diabetes has biopsy-proven non-alcoholic steatohepatitis (NASH) with significant steatosis and lobular inflammation. He has no heart failure, normal bone density, and no bladder pathology. His clinician wants an oral antidiabetic that also addresses the liver disease. Which agent is most appropriate?
A) Pioglitazone, because it has randomized trial evidence of histological improvement in NASH
B) Acarbose, because alpha-glucosidase inhibition reverses hepatic steatosis
C) Saxagliptin, because DPP-4 inhibitors are first-line for NASH
D) Rosiglitazone, because it carries the strongest NASH evidence among thiazolidinediones
E) Miglitol, because it is hepatically concentrated and targets steatosis
ANSWER: A
Rationale:
Pioglitazone is the only oral antidiabetic with consistent randomized trial evidence of histological improvement in NASH, reducing steatosis, lobular inflammation, and hepatocyte ballooning through PPAR-gamma (peroxisome proliferator-activated receptor gamma)-mediated reduction of hepatic lipotoxicity and insulin sensitization; with no heart failure, normal bone density, and no bladder pathology, the major TZD liabilities do not apply, so it is the appropriate choice.
Option B: Option B is incorrect because acarbose acts in the gut lumen and has no established NASH histological benefit.
Option C: Option C is incorrect because DPP-4 (dipeptidyl peptidase-4) inhibitors are not first-line for NASH and lack histological evidence.
Option D: Option D is incorrect because pioglitazone, not rosiglitazone, carries the NASH evidence, and rosiglitazone is generally avoided.
Option E: Option E is incorrect because miglitol is an alpha-glucosidase inhibitor without NASH benefit and is not hepatically targeted in a way that addresses steatosis.
7. A 70-year-old man with type 2 diabetes has been taking acarbose for postprandial hyperglycemia. Over the past year his renal function has declined, and his serum creatinine is now 2.4 mg/dL with an estimated glomerular filtration rate (eGFR) of 26 mL/min/1.73m2. What is the most appropriate management of his acarbose?
A) Continue acarbose unchanged, since less than 2 percent of the parent drug is absorbed
B) Double the acarbose dose to compensate for reduced efficacy in renal impairment
C) Continue acarbose but add a potassium binder to offset accumulation
D) Discontinue acarbose, because its renally excreted degradation products accumulate and it is contraindicated in significant renal impairment
E) Continue acarbose because renal function has no bearing on alpha-glucosidase inhibitor safety
ANSWER: D
Rationale:
Although acarbose has minimal parent-drug absorption, colonic bacterial degradation products are absorbed and renally excreted, so they accumulate as renal function declines; acarbose is contraindicated in significant renal impairment (for example, serum creatinine above 2.0 mg/dL or eGFR below 30 mL/min/1.73m2), so at a creatinine of 2.4 mg/dL with an eGFR of 26 it should be discontinued.
Option A: Option A is incorrect because the minimal parent-drug absorption does not make it safe; the metabolites are the concern.
Option B: Option B is incorrect because increasing the dose would worsen metabolite accumulation.
Option C: Option C is incorrect because the accumulating species are degradation products, not potassium, so a potassium binder does not address the contraindication.
Option E: Option E is incorrect because renal function is directly relevant to acarbose safety given renal excretion of its metabolites.
8. A 66-year-old man with type 2 diabetes is being considered for pioglitazone. At his visit he reports several weeks of painless gross hematuria that has not been investigated. What is the most appropriate action regarding pioglitazone?
A) Start pioglitazone immediately, since hematuria is unrelated to thiazolidinedione therapy
B) Defer pioglitazone and pursue urologic evaluation of the hematuria, because pioglitazone should be avoided with uninvestigated hematuria given its bladder cancer caution
C) Start pioglitazone but order a urine culture only, with no further workup
D) Start pioglitazone at a reduced dose, which removes any bladder cancer concern
E) Start rosiglitazone instead, since it carries an even stronger bladder cancer association requiring no workup
ANSWER: B
Rationale:
Pioglitazone carries an agent-specific bladder cancer caution, and current guidance is to avoid it in patients with active bladder cancer or uninvestigated hematuria. Painless gross hematuria in a 66-year-old man requires urologic evaluation before exposing him to pioglitazone, so the drug should be deferred pending workup.
Option A: Option A is incorrect because uninvestigated hematuria is precisely the setting where pioglitazone should be withheld, not started.
Option C: Option C is incorrect because a urine culture alone is inadequate evaluation for painless gross hematuria, which warrants formal urologic workup.
Option D: Option D is incorrect because dose reduction does not eliminate the bladder cancer concern in a patient with uninvestigated hematuria.
Option E: Option E is incorrect because rosiglitazone is not a preferred substitute and the bladder cancer caution specifically concerns pioglitazone; substituting it does not address the need to investigate the hematuria.
9. A 60-year-old woman with type 2 diabetes takes saxagliptin 5 mg daily. She is prescribed clarithromycin for a respiratory infection. Recognizing the relevant pharmacokinetic interaction, what adjustment to her saxagliptin is appropriate?
A) No change is needed, because saxagliptin is not metabolized by cytochrome P450 enzymes
B) Discontinue saxagliptin permanently because it cannot be used with any antibiotic
C) Increase saxagliptin to 10 mg to overcome accelerated metabolism
D) Switch saxagliptin to a higher-dose sulfonylurea for the duration of antibiotic therapy
E) Reduce saxagliptin to 2.5 mg, because clarithromycin is a potent CYP3A4 inhibitor and saxagliptin is a CYP3A4 substrate
ANSWER: E
Rationale:
Saxagliptin is a CYP3A4 (cytochrome P450 3A4) substrate, and clarithromycin is a potent CYP3A4 inhibitor, so co-administration raises saxagliptin exposure; the appropriate adjustment is to reduce saxagliptin from 5 mg to 2.5 mg.
Option A: Option A is incorrect because saxagliptin is in fact a CYP3A4 substrate, so the interaction is real.
Option B: Option B is incorrect because the interaction is managed by dose reduction, not permanent discontinuation, and it does not apply to all antibiotics.
Option C: Option C is incorrect because clarithromycin inhibits rather than induces metabolism, so increasing the dose would worsen exposure.
Option D: Option D is incorrect because switching to a higher-dose sulfonylurea introduces unnecessary hypoglycemia risk and is not the indicated management of this interaction.
10. A 55-year-old man started on pioglitazone three weeks ago returns frustrated that his home glucose readings have improved only minimally, and he asks to stop the drug. He is tolerating it well with no edema or weight gain. What is the most appropriate counseling and action?
A) Stop pioglitazone immediately, because lack of full effect at three weeks indicates treatment failure
B) Switch to rosiglitazone, which produces an immediate glycemic effect
C) Reassure him and continue pioglitazone, because the maximal glycemic effect of thiazolidinediones is delayed 6 to 12 weeks owing to gene-expression-dependent action
D) Add insulin now, since the pioglitazone is clearly ineffective
E) Double the dose immediately to force a faster response
ANSWER: C
Rationale:
Thiazolidinediones (TZDs) act through PPAR-gamma (peroxisome proliferator-activated receptor gamma)-driven changes in gene expression and protein synthesis, so their maximal glycemic effect is delayed 6 to 12 weeks. At three weeks, a modest response in a well-tolerating patient is expected, and the correct action is to reassure him and continue the drug.
Option A: Option A is incorrect because three weeks is too early to declare treatment failure given the known delayed onset.
Option B: Option B is incorrect because rosiglitazone shares the same delayed, gene-expression-dependent time course and does not act immediately.
Option D: Option D is incorrect because adding insulin is premature when the TZD has not yet reached its full effect.
Option E: Option E is incorrect because escalating the dose prematurely does not accelerate the inherently delayed onset and raises adverse-effect risk.
11. A 62-year-old insulin-resistant man with type 2 diabetes had a transient ischemic attack (TIA) two months ago. He has no heart failure, normal bone density, and no bladder pathology, and remains above goal on metformin. His clinician seeks an add-on agent with evidence beyond glycemic control in his specific setting. Which choice is best supported?
A) Acarbose, because it has the strongest secondary-prevention evidence after cerebrovascular events
B) Pioglitazone, because in insulin-resistant patients with a recent cerebrovascular event it reduced the risk of subsequent stroke or myocardial infarction
C) Saxagliptin, because DPP-4 inhibitors reduce recurrent stroke risk in insulin-resistant patients
D) Rosiglitazone, because it is the thiazolidinedione of choice after a cerebrovascular event
E) Miglitol, because alpha-glucosidase inhibition provides proven cerebrovascular protection
ANSWER: B
Rationale:
In insulin-resistant patients with a recent transient ischemic attack or stroke, pioglitazone reduced the risk of the composite of subsequent stroke or myocardial infarction, giving it an evidence-based secondary-prevention niche in exactly this setting; with no heart failure, normal bone density, and no bladder pathology, the major TZD liabilities do not apply.
Option A: Option A is incorrect because acarbose does not have established secondary-prevention evidence after cerebrovascular events that would support it here.
Option C: Option C is incorrect because DPP-4 (dipeptidyl peptidase-4) inhibitors are cardiovascular-neutral and do not have recurrent-stroke-reduction evidence in this population.
Option D: Option D is incorrect because rosiglitazone is generally avoided given its unfavorable cardiovascular profile and is not the thiazolidinedione of choice.
Option E: Option E is incorrect because miglitol, an alpha-glucosidase inhibitor, has no proven cerebrovascular protection.
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