Antidiabetic Drugs (Oral Hypoglycemics, Insulins) MCQs

Pharmacology · 141 free questions with answers & explanations.

1. SGLT2 inhibitors (dapagliflozin, empagliflozin) reduce cardiovascular mortality in type 2 diabetes independent of glycemic control. The primary mechanism responsible for their cardiorenal protection is:
2. A patient with type 2 diabetes is started on pioglitazone. After 3 months she complains of weight gain and ankle swelling. Which mechanism explains these side effects?
3. A patient with type 1 diabetes develops recurrent hypoglycemia unawareness. His insulin regimen uses NPH insulin twice daily. Switching him to which insulin analog would most reduce nocturnal hypoglycemia risk?
4. GLP-1 receptor agonists (liraglutide, semaglutide) produce weight loss as a major benefit. The mechanism of their weight-reducing effect is:
5. An SGLT2 inhibitor (empagliflozin) is started in a type 2 diabetic patient with CKD (eGFR 28 mL/min/1.73m²). Which specific beneficial renal mechanism justifies its use despite reduced glycosuric efficacy at low GFR?
6. Which pharmacogenomic factor determines whether a patient with type 2 diabetes will respond adequately to sulfonylurea monotherapy?
7. GLP-1 receptor agonists (e.g., semaglutide) demonstrate cardiovascular benefits beyond glucose control. Which mechanism is responsible for the heart failure benefit seen in these agents?
8. A patient on metformin for type 2 diabetes develops lactic acidosis after receiving IV contrast for CT angiography. The metformin-contrast interaction causing lactic acidosis is mediated by:
9. Which insulin preparation offers a flat peakless profile due to the formation of micro-precipitates at the injection site, providing basal insulin coverage for >24 hours?
10. Empagliflozin reduces cardiovascular mortality and hospitalisation for heart failure in diabetic patients independently of its glycaemic effect. The most widely accepted mechanism for its cardioprotective benefit is:
11. Tirzepatide is approved for type 2 diabetes and obesity and shows superior HbA1c reduction compared to semaglutide. Its unique pharmacology compared to GLP-1 receptor agonists is:
12. A patient with type 2 diabetes on metformin is started on a DPP-4 inhibitor (sitagliptin). The mechanism by which DPP-4 inhibitors increase insulin secretion is MOST accurately described as:
13. Ultra-long-acting insulin degludec has a unique pharmacokinetic profile compared to insulin glargine. The reason for its prolonged and flat action profile (>42 hours) is:
14. Empagliflozin, an SGLT2 inhibitor, reduces cardiovascular mortality in Type 2 diabetes beyond glycaemic control. The haemodynamic mechanism MOST responsible for cardiac benefit is:
15. Pioglitazone is a PPAR-gamma agonist. Its mechanism of improving insulin sensitivity involves which molecular event?
16. A patient on sitagliptin (DPP-4 inhibitor) develops an acute flare of joint pain. The MOST likely adverse effect is:
17. The 'dawn phenomenon' in insulin-treated Type 1 diabetes involves a pre-dawn rise in blood glucose due to:
18. SGLT-2 inhibitors reduce cardiovascular mortality in heart failure independent of their glycaemic effects. The principal cardioprotective mechanism currently supported by evidence involves:
19. A type 2 diabetic patient on metformin develops recurrent hypoglycaemia after adding a drug that increases GLP-1 receptor stimulation by preventing GLP-1 degradation. Which enzyme does this new drug inhibit, and what is its substrate specificity?
20. Tirzepatide, approved for type 2 diabetes and obesity, is a 'twincretin' because it acts as a dual agonist at which two receptors?
21. Which genetic variant most significantly increases the risk of lactic acidosis in patients taking metformin, particularly when combined with iodinated contrast agents or renal impairment?
22. Empagliflozin reduces cardiovascular mortality in Type 2 DM beyond glycaemic control. The mechanism responsible for its cardioprotective effect, distinct from SGLT2 inhibition, is proposed to be:
23. A patient on semaglutide (GLP-1 receptor agonist) reports significant nausea and a 4 kg weight loss over 3 months. The weight loss mechanism of GLP-1 receptor agonists primarily involves:
24. Alogliptin, saxagliptin, and sitagliptin (DPP-4 inhibitors) differ from pioglitazone in their effect on cardiovascular outcomes in CVOT trials. Which statement accurately reflects this difference?
25. A patient with Type 2 DM is switched from insulin glargine to insulin degludec. The physician explains that degludec forms multi-hexameric depot subcutaneously, leading to its ultra-long action. This depot dissolves at which rate, providing its PK advantage?
26. A T2DM patient on metformin and sitagliptin is switched to a SGLT2 inhibitor (empagliflozin) due to cardiovascular comorbidity. The cardiorenal protective mechanism of empagliflozin beyond glucose-lowering operates through:
27. Insulin degludec has an ultra-long duration of action (>42 hours) compared to insulin glargine (20–24 hours). The structural basis of degludec's prolonged action is:
28. A patient with T2DM is considered for tirzepatide therapy. Tirzepatide's superior glycemic and weight-lowering efficacy compared to semaglutide is attributed to its dual agonism at:
29. In a patient with T2DM, semaglutide reduces cardiovascular events (SUSTAIN-6 trial). The mechanism of GLP-1 agonist-mediated cardiovascular protection that is most well-supported is:
30. A patient with type 2 DM has HbA1c of 9.2% and is started on a GLP-1 receptor agonist. The weight loss observed is primarily mediated by which mechanism distinct from its glucose-lowering action?
31. Which pharmacogenomic variant is most strongly associated with lactic acidosis risk in patients on metformin, beyond renal impairment?
32. Tirzepatide (dual GIP/GLP-1 receptor agonist) is now approved for type 2 diabetes and obesity. How does GIP receptor agonism ADD to the benefits of GLP-1 receptor agonism?
33. SGLT2 inhibitors (empagliflozin, dapagliflozin) reduce major adverse cardiovascular events in patients with established CVD or HFrEF. Their cardiovascular benefit is largely attributed to which mechanism BEYOND glucose lowering?
34. A patient on a GLP-1 receptor agonist (liraglutide) requires dose adjustment. GLP-1R agonists stimulate insulin secretion via a glucose-dependent mechanism. The molecular explanation for this glucose-dependency is:
35. A 28-year-old woman with type 1 diabetes using insulin degludec complains of recurrent hypoglycemic episodes before breakfast despite adequate meal planning. Compared to insulin glargine, what pharmacokinetic property of degludec REDUCES this risk?
36. Tirzepatide represents a therapeutic advance in type 2 diabetes management because unlike semaglutide it is:
37. The Somogyi effect in insulin-treated diabetes differs from the dawn phenomenon in that the morning hyperglycemia is caused by:
38. Canagliflozin is associated with an increased risk of lower limb amputations compared to other SGLT2 inhibitors. The proposed mechanism involves:
39. A patient with T2DM and an eGFR of 28 mL/min/1.73 m² is on metformin. The risk of lactic acidosis with metformin in renal impairment is due to:
40. Tirzepatide (approved 2022) demonstrates superior HbA1c reduction compared to GLP-1 receptor agonists alone. Its additional mechanism compared to semaglutide is:
41. A patient is started on glimepiride and develops recurrent hypoglycemia during Ramadan fasting. The sulfonylurea's pharmacogenomic risk in this patient is most related to:
42. SGLT2 inhibitors (empagliflozin, dapagliflozin) reduce cardiovascular mortality in type 2 diabetes independent of glycemic control. The primary mechanism responsible for their cardioprotective effect is thought to be:
43. Tirzepatide (Mounjaro) differs mechanistically from semaglutide in that it is which type of receptor agonist?
44. A type 2 diabetic patient with CKD (eGFR 28 mL/min/1.73m²) is on metformin. Which of the following best describes the risk and the threshold at which metformin should be discontinued?
45. Insulin degludec (Tresiba) has a longer, flatter action profile than insulin glargine because of which pharmacokinetic property?
46. DPP-4 inhibitors (gliptins) are weight-neutral and do not cause hypoglycemia. The molecular mechanism involves inhibiting DPP-4 from cleaving the N-terminal dipeptide of which endogenous substrate?
47. Empagliflozin reduces cardiovascular mortality in type 2 diabetes independently of glycemic control. Which cardiac hemodynamic mechanism is primarily responsible for this benefit?
48. A patient on metformin has a GFR that drops from 60 to 30 mL/min/1.73m² following contrast administration. Which pharmacokinetic reason necessitates metformin discontinuation?
49. Tirzepatide is superior to semaglutide in weight reduction in clinical trials. Its pharmacological advantage is based on which dual mechanism?
50. SGLT2 inhibitors reduce cardiovascular mortality in heart failure independent of glycaemic control. The proposed mechanism responsible for cardiac benefit is:
51. A patient with T2DM on metformin develops lactic acidosis. The sub-cellular mechanism responsible for this adverse effect is metformin's inhibition of:
52. A 60-year-old man with T2DM, CKD stage 3b (eGFR 35), and established atherosclerotic cardiovascular disease needs glycaemic optimisation. Which agent provides both cardiovascular mortality reduction and is safe at this eGFR?
53. The 'incretin effect' exploited by GLP-1 receptor agonists means their insulinotropic effect is:
54. Semaglutide, a GLP-1 receptor agonist, causes significantly greater weight loss than older GLP-1RAs. This is partly explained by its:
55. A diabetic patient with CKD stage 3b (eGFR 35 mL/min/1.73m²) and heart failure is started on an SGLT2 inhibitor. Which sub-mechanism specifically explains the cardiorenal protective effect independent of glucose lowering?
56. A patient on metformin presents with severe lactic acidosis. The primary cellular mechanism of metformin-induced lactic acid accumulation is:
57. Tirzepatide, approved for type 2 diabetes and obesity, differs from semaglutide in that it is a:
58. Empagliflozin reduces cardiovascular mortality in type 2 diabetes patients with established cardiovascular disease. Beyond glycaemic lowering, its major cardiovascular protective mechanism involves:
59. A type 2 diabetic patient on metformin presents with lactic acidosis. Which pharmacokinetic property of metformin most predisposes to this complication when renal function is impaired?
60. Dulaglutide is a GLP-1 receptor agonist with a half-life allowing once-weekly dosing. The prolonged action is achieved by:
61. Sitagliptin, a DPP-4 inhibitor, is weight-neutral compared to sulphonylureas. The reason sitagliptin does not cause hypoglycaemia as monotherapy is:
62. SGLT2 inhibitors like empagliflozin reduce the risk of hospitalization for heart failure independent of glycemic control. The most accepted mechanism for this cardioprotective effect involves:
63. A patient on metformin develops lactic acidosis. The metabolic mechanism by which metformin can cause this is:
64. The incretin effect refers to the greater insulin secretory response to oral glucose versus IV glucose at matching plasma glucose levels. Which receptor does GLP-1 activate to stimulate insulin secretion in a glucose-dependent manner?
65. A patient with type 2 diabetes has an eGFR of 30 mL/min/1.73m2. Which of the following antidiabetic drugs can be safely continued in this patient without dose adjustment?
66. Insulin degludec has a duration of action exceeding 42 hours. What structural modification of native insulin accounts for this ultra-long action?
67. Tirzepatide is approved for type 2 diabetes and obesity. What is unique about its receptor pharmacology?
68. Empagliflozin (an SGLT-2 inhibitor) demonstrates cardiovascular mortality benefit in diabetic patients with established heart failure. Which mechanism BEST explains its haemodynamic benefit independent of glucose lowering?
69. A patient with Type 2 diabetes is started on a GLP-1 receptor agonist (liraglutide). Which effect does NOT occur via GLP-1 receptor activation?
70. Regarding insulin pharmacokinetics: A patient takes 0.5 units/kg of insulin glargine (body weight 70 kg). The volume of distribution is approximately 0.15 L/kg. Calculate the expected plasma drug amount distributed at steady state. (Note: This question tests Vd conceptually; select the statement about insulin glargine PK that is most accurate.)
71. Metformin is contraindicated in patients with estimated GFR < 30 mL/min/1.73 m². The primary reason is:
72. SGLT2 inhibitors like empagliflozin reduce cardiovascular mortality in patients with type 2 diabetes and established CVD. A key non-glycaemic mechanism contributing to this cardiac benefit is:
73. A patient on metformin develops B12 deficiency after 5 years of therapy. The most plausible mechanism is:
74. Which insulin preparation has the slowest and most prolonged onset-free-peak absorption profile due to formation of hexameric microprecipitates at physiological pH?
75. GLP-1 receptor agonists (e.g., semaglutide) produce weight loss through which central mechanism?
76. Pioglitazone, a thiazolidinedione, reduces insulin resistance primarily by acting as a full agonist at which nuclear receptor?
77. A 62-year-old man with type 2 diabetes and chronic kidney disease (eGFR 30 mL/min) develops heart failure. Which antidiabetic drug has the strongest evidence for cardiovascular mortality benefit AND is safe at this eGFR level?
78. Dapagliflozin reduces HbA1c in type 2 diabetes by a mechanism entirely independent of insulin secretion or action. This mechanism is:
79. Exenatide is a GLP-1 receptor agonist with a half-life of ~2.4 hours despite GLP-1 itself having a half-life of <2 minutes. The structural modification that confers this resistance to degradation is:
80. A patient with type 2 diabetes is switched from neutral protamine Hagedorn (NPH) insulin to insulin glargine for basal coverage. The property of glargine that makes it truly 'peakless' is:
81. Pioglitazone (thiazolidinedione) causes fluid retention and weight gain as major adverse effects. The molecular mechanism linking PPAR-gamma activation to sodium and water retention is:
82. A 62-year-old man with type 2 diabetes and CKD stage 3b (eGFR 38 mL/min/1.73m2) is on metformin. His physician is concerned about metformin's risk in this situation. At which eGFR threshold is metformin absolutely contraindicated as per current guidelines?
83. Canagliflozin is prescribed for a patient with type 2 diabetes and established cardiovascular disease. Beyond glycaemic control, which outcome benefit is most directly linked to its unique mechanism of reducing renal sodium-glucose reabsorption?
84. A type 1 diabetic on intensive insulin therapy notices that after several years of tight control, his hypoglycaemia warning symptoms have diminished. This syndrome of hypoglycaemia unawareness is related to failure of which counterregulatory response?
85. A physician prescribes semaglutide once weekly for a patient with type 2 diabetes and obesity. The primary mechanism by which semaglutide reduces appetite and body weight is:
86. SGLT2 inhibitors reduce HbA1c, but their cardiovascular and renal benefits (reduced MACE, hospitalisation for heart failure, and CKD progression) appear to be partly independent of glycaemic control. The primary mechanism underlying their cardiorenal benefit is:
87. Tirzepatide, approved for type 2 diabetes and obesity, is a 'twincretin.' Which receptors does it simultaneously agonize?
88. A patient on metformin 2 g/day requires an iodinated contrast CT. Which approach is evidence-based regarding metformin management?
89. Degludec (insulin degludec) has a much longer half-life and lower day-to-day variability compared to glargine. The pharmacokinetic basis for this is:
90. Empagliflozin reduces cardiovascular mortality in type 2 diabetes independent of its glycaemic effect. The primary renal mechanism responsible for its glucose-lowering action is:
91. A diabetic patient with HbA1c 9.2% and significant obesity is started on semaglutide. Which mechanism correctly explains its glucose-lowering and weight-reducing effect?
92. A patient on metformin develops severe lactic acidosis after an iodinated contrast procedure. The mechanism by which metformin predisposes to lactic acidosis is:
93. Insulin glargine has a prolonged, peakless action profile compared with regular insulin. The pharmacokinetic basis for this is:
94. A patient with type 2 diabetes is started on empagliflozin. Beyond glucose lowering, which mechanism underlies its proven cardiovascular mortality benefit in the EMPA-REG OUTCOME trial?
95. Which of the following correctly describes the pharmacological difference between sitagliptin and liraglutide in their action on the incretin axis?
96. Insulin glargine (Lantus) provides 24-hour basal insulin coverage. Which physicochemical property accounts for its prolonged, peakless action?
97. Metformin's primary mechanism of action that reduces hepatic glucose production involves activation of which intracellular pathway?
98. A 58-year-old man with type 2 diabetes and a history of heart failure with reduced ejection fraction (HFrEF) is started on empagliflozin. Beyond glucose lowering, the cardiovascular benefit of SGLT-2 inhibitors in HFrEF is BEST explained by:
99. A diabetic patient on metformin develops lactic acidosis after contrast-enhanced CT scan. Which pharmacokinetic property of metformin is MOST responsible for the accumulation leading to this adverse effect?
100. A patient on insulin glargine asks why it cannot be mixed with short-acting insulin in the same syringe. The pharmacological reason is:
101. SGLT-2 inhibitors (gliflozins) reduce HbA1c by glucosuria but also confer cardiovascular and renal benefits independent of glycaemic control. The primary mechanism of their cardiorenal protection involves:
102. A patient with type 2 diabetes and obesity is commenced on a GLP-1 receptor agonist. Which statement correctly describes the mechanism of glucose-dependent insulin secretion by this drug class?
103. Metformin is contraindicated when eGFR falls below 30 mL/min/1.73m2 primarily because renal impairment increases the risk of which potentially fatal complication?
104. A patient with type 1 diabetes uses insulin glargine as basal insulin. Which pharmacokinetic property gives insulin glargine its 'peakless' 24-hour duration of action?
105. Dapagliflozin reduces HbA1c and also has proven cardiovascular and renal benefits in T2DM. Its mechanism is:
106. Exenatide is a GLP-1 receptor agonist used in T2DM. Its glucose-lowering effects are glucosedependent, meaning it does not cause hypoglycaemia in normoglycaemia. The reason for this glucosedependency is:
107. Metformin's primary mechanism of action in reducing hepatic glucose production involves activation of which enzyme?
108. A patient on sitagliptin (DPP-4 inhibitor) also takes an ACE inhibitor. The combination increases risk of which adverse effect?
109. Which insulin preparation is most appropriate for continuous subcutaneous insulin infusion (CSII) pump therapy, and what property makes it suitable?
110. A patient with T2DM and CKD stage 3b (eGFR 35 mL/min/1.73m²) is on metformin. Metformin should be dose-reduced or discontinued at this eGFR because:
111. SGLT2 inhibitors reduce cardiovascular mortality in HFrEF independent of their glucose-lowering effect. The mechanism most directly responsible for their cardiac benefit is:
112. Liraglutide, a GLP-1 receptor agonist, reduces HbA1c by multiple mechanisms. Which mechanism is glucose-INDEPENDENT and does not risk hypoglycemia?
113. Pioglitazone (a TZD) activates PPARgamma in adipose tissue, liver, and muscle. In a patient with T2DM and non-alcoholic fatty liver disease, which additional benefit has been demonstrated in clinical trials?
114. A patient with type 2 diabetes and heart failure with reduced EF is started on empagliflozin. The cardiac benefit of SGLT2 inhibitors in heart failure is PRIMARILY attributed to:
115. The incretin effect is reduced in type 2 diabetes. GLP-1 receptor agonists (e.g., semaglutide) lower blood glucose by all of the following mechanisms EXCEPT:
116. Pioglitazone reduces insulin resistance by acting as a PPAR-gamma agonist. A serious long-term adverse effect that limits its use in high-risk patients is:
117. A 55-year-old type 2 diabetic patient on glibenclamide develops severe hypoglycaemia. Compared to glipizide, glibenclamide causes more prolonged hypoglycaemia because:
118. Which insulin preparation is most suitable for use in continuous subcutaneous insulin infusion (insulin pump therapy)?
119. A patient with type 2 diabetes on metformin develops recurrent hypoglycemia after adding a new oral agent. On examination, there is bilateral lower leg edema. The newly added drug is most likely:
120. Empagliflozin reduces cardiovascular mortality in patients with type 2 diabetes and established CVD (EMPA-REG OUTCOME trial). The proposed mechanism of cardiovascular benefit beyond glucose lowering involves:
121. Liraglutide (GLP-1 receptor agonist) differs from sitagliptin (DPP-4 inhibitor) in its degree of GLP-1 receptor activation. Liraglutide achieves supraphysiological GLP-1 effects because:
122. A type 1 diabetic on insulin glargine experiences persistent hypoglycemia at 3 AM despite appropriate bedtime dose. A contributing factor unique to insulin glargine's pharmacokinetics is:
123. A 55-year-old type 2 diabetic patient with an eGFR of 25 mL/min/1.73m2 (CKD stage 4) requires initiation of GLP-1 receptor agonist therapy. Which agent is MOST appropriate given his renal function?
124. Insulin resistance in type 2 diabetes involves impaired post-receptor signaling. At the molecular level, which specific kinase is the earliest critically impaired step in the insulin receptor signal transduction cascade in insulin-resistant adipocytes?
125. Tirzepatide is a recently approved agent for type 2 diabetes and obesity. What distinguishes its mechanism from GLP-1 receptor agonists like semaglutide?
126. A 40-year-old newly diagnosed type 2 diabetic also has non-alcoholic fatty liver disease (NAFLD). Among the antidiabetic agents below, which has the strongest evidence for histological improvement (reduction in NAFLD activity score and fibrosis) and what is its proposed hepatic mechanism?
127. Tirzepatide is a dual GIP/GLP-1 receptor agonist approved for type 2 diabetes and obesity. Compared to selective GLP-1 agonists, the additional GIP receptor agonism contributes to greater weight loss through which mechanism?
128. A patient with type 2 diabetes on metformin develops lactic acidosis post-contrast CT scan. The mechanism by which metformin predisposes to lactic acidosis under contrast nephropathy is:
129. Insulin degludec (Tresiba) has an ultra-long duration of action (~42 hours) compared to insulin glargine (~24 hours). The structural basis for this extended duration is:
130. Dapagliflozin, an SGLT2 inhibitor, reduces cardiovascular events in heart failure with reduced ejection fraction (HFrEF) independent of glycemic control. Its primary mechanism responsible for this benefit is:
131. Liraglutide (a GLP-1 receptor agonist) has a much longer half-life than native GLP-1. The structural modification responsible for this is:
132. Insulin lispro differs from regular insulin in its rapid onset. The structural modification causing faster absorption from subcutaneous tissue is:
133. Metformin reduces hepatic glucose production. The molecular mechanism by which metformin activates AMPK in hepatocytes is:
134. An SGLT-2 inhibitor is prescribed to a diabetic patient with heart failure with reduced ejection fraction. Beyond glycaemic control, the direct cardiac benefit is attributed to:
135. A type 2 diabetic patient on metformin and a GLP-1 receptor agonist achieves inadequate glycaemic control. A DPP-4 inhibitor is considered next. Why is adding a DPP-4 inhibitor to a GLP-1 RA not recommended?
136. Insulin detemir achieves its prolonged duration of action (18–24 hours) primarily through which mechanism?
137. Pioglitazone is a PPAR-gamma agonist. Which of the following best explains its mechanism of insulin sensitisation?
138. A patient with type 2 diabetes, eGFR 25 mL/min/1.73m², and HbA1c 9.2% requires intensification of therapy. Which oral antidiabetic should be avoided?
139. Insulin lispro is a rapid-acting insulin analogue. Compared to regular human insulin, what structural modification confers its faster onset?
140. Thiazolidinediones (glitazones) such as pioglitazone cause peripheral insulin sensitisation but are associated with fluid retention and heart failure. The molecular target of pioglitazone is:
141. Semaglutide (weekly GLP-1 RA) produces greater weight loss than liraglutide (daily GLP-1 RA). The pharmacokinetic feature explaining semaglutide's extended half-life is: