Diabetes mellitus: therapeutic strategies and drug classes MCQs With Answer

Introduction: This quiz collection on “Diabetes mellitus: therapeutic strategies and drug classes” is designed specifically for M.Pharm students studying Pharmacotherapeutics I (MPP 102T). It focuses on mechanistic insights, clinical indications, adverse effect profiles, and practical prescribing considerations for major antidiabetic drug classes. Questions probe beyond memorization, addressing signaling pathways (e.g., AMPK, PPAR-γ), renal and cardiovascular outcomes, pharmacokinetic distinctions of insulin analogs, and drug–disease contraindications. Use these MCQs to assess readiness for advanced therapeutics discussions, clinical case formulation, and rational selection of agents in type 1 and type 2 diabetes management. Detailed understanding will aid in optimizing therapy and anticipating safety issues.

Q1. Which of the following is considered the first-line pharmacotherapy for most patients with type 2 diabetes mellitus due to its insulin-sensitizing effect and proven cardiovascular benefit profile?

• Insulin glargine
• Metformin
• Glibenclamide (glyburide)
• Pioglitazone

Correct Answer: Metformin

Q2. What is the primary cellular mechanism by which metformin lowers hepatic glucose production?

• Direct stimulation of pancreatic beta cell insulin secretion
• Activation of AMP-activated protein kinase (AMPK) leading to inhibition of hepatic gluconeogenesis
• Inhibition of dipeptidyl peptidase-4 (DPP-4) increasing incretin levels
• Blockade of renal SGLT2 to increase urinary glucose excretion

Correct Answer: Activation of AMP-activated protein kinase (AMPK) leading to inhibition of hepatic gluconeogenesis

Q3. Sulfonylureas lower blood glucose primarily by which of the following actions on pancreatic β-cells?

• Agonism at GLP-1 receptors to enhance glucose-dependent insulin release
• Closure of ATP-sensitive K+ (KATP) channels on β-cell membranes, causing depolarization and insulin secretion
• Inhibition of intestinal α-glucosidases to reduce carbohydrate absorption
• Upregulation of PPAR-γ to improve peripheral insulin sensitivity

Correct Answer: Closure of ATP-sensitive K+ (KATP) channels on β-cell membranes, causing depolarization and insulin secretion

Q4. Which antidiabetic drug class is most strongly associated with symptomatic hypoglycaemia when used as monotherapy in elderly patients?

• Biguanides (metformin)
• SGLT2 inhibitors (e.g., empagliflozin)
• Sulfonylureas (e.g., glimepiride)
• Thiazolidinediones (e.g., pioglitazone)

Correct Answer: Sulfonylureas (e.g., glimepiride)

Q5. Thiazolidinediones (TZDs) such as pioglitazone exert their antidiabetic effect primarily through:

• Inhibition of intestinal carbohydrate digestion enzymes
• Agonism of peroxisome proliferator-activated receptor gamma (PPAR-γ) to increase insulin sensitivity
• Enhancement of renal glucose excretion via proximal tubule transporters
• Stimulation of cyclic AMP in β-cells to increase insulin release

Correct Answer: Agonism of peroxisome proliferator-activated receptor gamma (PPAR-γ) to increase insulin sensitivity

Q6. What is the principal renal target and mechanism of action of SGLT2 inhibitors in lowering plasma glucose?

• Inhibition of renal SGLT2 in the proximal tubule to reduce glucose reabsorption and increase urinary glucose excretion
• Enhancement of renal insulin sensitivity via proximal tubule PPAR activation
• Inhibition of renal gluconeogenesis by blocking mitochondrial complex I
• Stimulation of renal GLP-1 secretion to reduce blood glucose

Correct Answer: Inhibition of renal SGLT2 in the proximal tubule to reduce glucose reabsorption and increase urinary glucose excretion

Q7. Beyond glycaemic control, which clinically important benefit has been demonstrated in outcome trials for some SGLT2 inhibitors such as empagliflozin and canagliflozin?

• Marked increase in HDL cholesterol with no renal effects
• Reduction in heart failure hospitalizations and slowing of chronic kidney disease progression
• Prevention of all-cause infections due to glucose lowering in urine
• Significant stimulation of pancreatic β-cell regeneration

Correct Answer: Reduction in heart failure hospitalizations and slowing of chronic kidney disease progression

Q8. Dipeptidyl peptidase-4 (DPP-4) inhibitors lower blood glucose by which of the following mechanisms?

• Direct insulin receptor sensitization in muscle and adipose tissue
• Inhibition of renal glucose reabsorption
• Prolonging endogenous incretin hormones (GLP-1 and GIP) by preventing their enzymatic degradation
• Blocking intestinal glucose transporters to reduce absorption

Correct Answer: Prolonging endogenous incretin hormones (GLP-1 and GIP) by preventing their enzymatic degradation

Q9. Which of the following effects is characteristic of GLP-1 receptor agonists (e.g., liraglutide, semaglutide) and contributes to their clinical use in type 2 diabetes?

• Glucose-independent, continuous stimulation of insulin causing high hypoglycaemia risk
• Glucose-dependent augmentation of insulin secretion, delayed gastric emptying, and weight reduction
• Direct inhibition of hepatic gluconeogenesis via mitochondrial toxicity
• Primary reduction of fasting glucose by promoting renal glucose excretion

Correct Answer: Glucose-dependent augmentation of insulin secretion, delayed gastric emptying, and weight reduction

Q10. Which therapy is essential and non-optional for patients with absolute insulin deficiency as seen in type 1 diabetes mellitus?

• Metformin
• Sulfonylurea
• Long-term insulin replacement therapy
• SGLT2 inhibitor monotherapy

Correct Answer: Long-term insulin replacement therapy

Q11. Metformin carries an increased risk of lactic acidosis in which clinical context, necessitating caution or contraindication?

• Severe renal impairment or acute renal failure
• Mild hyperlipidaemia with normal kidney function
• Controlled hypertension on ACE inhibitors
• Well-compensated heart failure without hypoxia

Correct Answer: Severe renal impairment or acute renal failure

Q12. Alpha-glucosidase inhibitors (e.g., acarbose) reduce postprandial glucose excursions primarily by which mechanism?

• Enhancing insulin sensitivity via PPAR-γ activation
• Inhibiting intestinal brush-border α-glucosidases to slow carbohydrate digestion and absorption
• Stimulating incretin secretion from L-cells
• Increasing renal glucose excretion through SGLT1 blockade

Correct Answer: Inhibiting intestinal brush-border α-glucosidases to slow carbohydrate digestion and absorption

Q13. Which antidiabetic drug class is most commonly associated with weight gain and peripheral edema due to fluid retention and increased adipogenesis?

• SGLT2 inhibitors
• Thiazolidinediones (TZDs)
• GLP-1 receptor agonists
• Alpha-glucosidase inhibitors

Correct Answer: Thiazolidinediones (TZDs)

Q14. Use of SGLT2 inhibitors is specifically associated with an increased risk of which class of infections?

• Upper respiratory tract infections
• Genital mycotic (fungal) and urinary tract infections
• Opportunistic tuberculosis reactivation
• Systemic viral infections such as herpes zoster

Correct Answer: Genital mycotic (fungal) and urinary tract infections

Q15. Meglitinides (e.g., repaglinide, nateglinide) differ from sulfonylureas in that they are:

• Long-acting agents requiring once-daily dosing
• Short-acting insulin secretagogues with rapid onset, taken before meals to control postprandial glucose
• Renally excreted incretin mimetics
• Primarily SGLT1 inhibitors acting on the intestine

Correct Answer: Short-acting insulin secretagogues with rapid onset, taken before meals to control postprandial glucose

Q16. Which antidiabetic medication class is contraindicated or used with extreme caution in patients with New York Heart Association (NYHA) class III–IV heart failure because of fluid retention risk?

• GLP-1 receptor agonists
• Thiazolidinediones (TZDs)
• SGLT2 inhibitors
• DPP-4 inhibitors

Correct Answer: Thiazolidinediones (TZDs)

Q17. Which drug class is most effective at specifically reducing postprandial hyperglycemia by interfering with carbohydrate absorption in the intestine?

• Biguanides (metformin)
• Alpha-glucosidase inhibitors (e.g., acarbose)
• SGLT2 inhibitors
• Basal insulin analogs (e.g., insulin detemir)

Correct Answer: Alpha-glucosidase inhibitors (e.g., acarbose)

Q18. Rapid-acting insulin analogs such as insulin lispro achieve faster absorption than regular human insulin primarily because:

• They are administered at double the dose to increase absorption
• Amino acid substitutions prevent hexamer formation, favoring monomeric absorption from the subcutaneous tissue
• They inhibit local tissue lipolysis enhancing capillary flow
• They are formulated with absorption enhancers that increase capillary permeability

Correct Answer: Amino acid substitutions prevent hexamer formation, favoring monomeric absorption from the subcutaneous tissue

Q19. Which laboratory parameter is the recommended standard for assessing long-term (approximately 2–3 months) glycaemic control in diabetic patients?

• Fasting plasma glucose
• Fructosamine
• Glycated haemoglobin (HbA1c)
• Postprandial 2-hour glucose

Correct Answer: Glycated haemoglobin (HbA1c)

Q20. Combining which of the following antidiabetic therapies most increases the risk of severe hypoglycaemia and therefore requires dose adjustment and close monitoring?

• Metformin plus an SGLT2 inhibitor
• Sulfonylurea plus exogenous insulin
• Metformin plus pioglitazone
• DPP-4 inhibitor plus GLP-1 receptor agonist

Correct Answer: Sulfonylurea plus exogenous insulin

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