Alpha-glucosidase inhibitors – Acarbose MCQs With Answer

Alpha-glucosidase inhibitors – Acarbose MCQs With Answer

Alpha-glucosidase inhibitors, particularly acarbose, are essential oral antidiabetic agents that slow carbohydrate digestion to reduce postprandial hyperglycemia. B. Pharm students should master acarbose’s mechanism of action as a competitive, reversible inhibitor of intestinal alpha-glucosidases, its minimal systemic absorption, common gastrointestinal adverse effects, contraindications (e.g., inflammatory bowel disease, short bowel syndrome), dosing principles, and unique management of hypoglycemia (use glucose, not sucrose). Understanding drug interactions, effects on HbA1c and liver enzymes, and clinical use in combination therapy enhances rational pharmacotherapy. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which best describes the primary mechanism of action of acarbose?

• Stimulates pancreatic insulin secretion
• Inhibits hepatic gluconeogenesis
• Competitive, reversible inhibition of intestinal alpha-glucosidases
• Enhances peripheral glucose uptake by muscle

Correct Answer: Competitive, reversible inhibition of intestinal alpha-glucosidases

Q2. Acarbose mainly reduces which component of blood glucose control?

• Fasting plasma glucose primarily
• Postprandial plasma glucose peaks
• Basal insulin secretion
• Renal glucose reabsorption

Correct Answer: Postprandial plasma glucose peaks

Q3. What is the usual initial dosing strategy for acarbose in adults?

• Start 100 mg once daily at bedtime
• Start 25 mg three times daily with first bite of each meal
• Start 10 mg twice daily before meals
• Start 300 mg once daily with breakfast

Correct Answer: Start 25 mg three times daily with first bite of each meal

Q4. Which adverse effect is most commonly associated with acarbose?

• Hypoglycemia as monotherapy
• Weight gain
• Gastrointestinal effects like flatulence and diarrhea
• Severe hypokalemia

Correct Answer: Gastrointestinal effects like flatulence and diarrhea

Q5. If a patient on acarbose develops hypoglycemia while also taking a sulfonylurea, what is the recommended treatment?

• Give sucrose-containing foods (table sugar)
• Give oral glucose (dextrose) or intravenous glucose
• Give starch-rich foods only
• Give sucrose syrup followed by maltose

Correct Answer: Give oral glucose (dextrose) or intravenous glucose

Q6. Which condition is a contraindication to acarbose therapy?

• Type 2 diabetes mellitus with obesity
• Inflammatory bowel disease or intestinal obstruction
• Mild renal impairment
• Controlled hypertension

Correct Answer: Inflammatory bowel disease or intestinal obstruction

Q7. Acarbose’s systemic absorption is best described as:

• Extensive with high plasma levels
• Moderate, requiring dose adjustments for hepatic impairment
• Minimal; most action is local in the gut
• Complete absorption with renal excretion of unchanged drug

Correct Answer: Minimal; most action is local in the gut

Q8. How does acarbose affect HbA1c on average when used appropriately?

• Increases HbA1c by 1–2%
• No effect on HbA1c
• Reduces HbA1c by approximately 0.5–1.0%
• Reduces HbA1c by >2%

Correct Answer: Reduces HbA1c by approximately 0.5–1.0%

Q9. Which enzyme(s) in the intestine are inhibited by acarbose?

• Alpha-glucosidases (maltase, sucrase, isomaltase)
• Lipoprotein lipase
• Beta-glucosidase only
• Peptidases and proteases

Correct Answer: Alpha-glucosidases (maltase, sucrase, isomaltase)

Q10. Acarbose chemical nature is best classified as:

• A synthetic sulfonylurea
• A biguanide derivative
• An oligosaccharide that mimics carbohydrates
• A GLP-1 receptor agonist peptide

Correct Answer: An oligosaccharide that mimics carbohydrates

Q11. When increasing acarbose dose from initial to maintenance, the main reason for gradual titration is:

• To avoid renal toxicity
• To reduce gastrointestinal adverse effects and improve tolerability
• To prevent hypoglycemia due to rapid absorption
• To allow time for hepatic enzyme induction

Correct Answer: To reduce gastrointestinal adverse effects and improve tolerability

Q12. Which of the following is a potential laboratory abnormality requiring monitoring with acarbose?

• Serum potassium elevation
• Elevated liver transaminases
• Marked leukopenia
• Hypochloremia

Correct Answer: Elevated liver transaminases

Q13. Acarbose is most appropriately combined with which oral antidiabetic for complementary effects?

• Insulin only, never use with oral agents
• Metformin or sulfonylureas for additive glycemic control
• Thyroid hormone replacement
• Statins to enhance glucose lowering

Correct Answer: Metformin or sulfonylureas for additive glycemic control

Q14. Which statement about acarbose and weight is correct?

• Acarbose typically causes significant weight gain
• Acarbose is weight-neutral or may cause slight weight loss
• Acarbose causes dramatic weight loss in all patients
• Acarbose increases appetite leading to weight gain

Correct Answer: Acarbose is weight-neutral or may cause slight weight loss

Q15. If a patient on acarbose and insulin becomes hypoglycemic, which carbohydrate source is ineffective due to acarbose action?

• Glucose tablets (dextrose)
• Fruit juice containing free glucose
• Table sugar (sucrose) or sucrose-containing foods
• Intravenous dextrose

Correct Answer: Table sugar (sucrose) or sucrose-containing foods

Q16. What is the recommended action when elevated liver enzymes occur during acarbose therapy?

• Continue therapy and recheck labs in 6 months
• Immediately stop acarbose and consider alternative therapy
• Add a hepatoprotective supplement while continuing acarbose
• Double the dose of acarbose to overcome enzyme elevation

Correct Answer: Immediately stop acarbose and consider alternative therapy

Q17. Which pharmacokinetic feature explains why systemic side effects of acarbose are uncommon?

• Rapid hepatic metabolism to active metabolites
• Extensive first-pass renal elimination
• Poor systemic absorption and local intestinal action
• High protein binding causing sequestration

Correct Answer: Poor systemic absorption and local intestinal action

Q18. Acarbose’s efficacy in lowering postprandial glucose is greatest when:

• Carbohydrate content of the meal is high
• Avoiding carbohydrates entirely
• Taking it several hours after meals
• Used only with bedtime snack

Correct Answer: Carbohydrate content of the meal is high

Q19. Which patient population requires caution or avoidance of acarbose?

• Patients with mild hyperlipidemia
• Patients with irritable bowel syndrome, short bowel, or chronic intestinal disease
• Patients with well-controlled type 2 diabetes on diet alone
• Patients with hypothyroidism

Correct Answer: Patients with irritable bowel syndrome, short bowel, or chronic intestinal disease

Q20. Which statement about acarbose and renal impairment is most accurate?

• It is contraindicated in all degrees of renal impairment
• Caution is advised in severe renal impairment; dose adjustment may be needed
• No dose adjustment is ever necessary
• It is cleared primarily by the kidneys as unchanged drug

Correct Answer: Caution is advised in severe renal impairment; dose adjustment may be needed

Q21. The structural basis for acarbose’s inhibitory action is that it:

• Is a peptide analog of insulin
• Mimics oligosaccharide substrates and binds the enzyme active site
• Forms covalent bonds with intestinal enzymes
• Alters intestinal pH to denature enzymes

Correct Answer: Mimics oligosaccharide substrates and binds the enzyme active site

Q22. Which monitoring parameter is most relevant when initiating acarbose?

• Serum amylase levels weekly
• Liver function tests periodically
• Daily serum electrolytes
• Thyroid function tests

Correct Answer: Liver function tests periodically

Q23. Acarbose can interact with which of the following to increase gastrointestinal effects?

• Metformin
• ACE inhibitors
• Topical corticosteroids
• Antihistamines

Correct Answer: Metformin

Q24. Which pharmacodynamic effect is NOT expected with acarbose?

• Delay in intestinal carbohydrate hydrolysis
• Reduction in post-meal glycemic excursions
• Direct stimulation of insulin gene transcription
• Lowering of HbA1c modestly over months

Correct Answer: Direct stimulation of insulin gene transcription

Q25. In clinical practice, acarbose is most useful for patients who:

• Have predominant fasting hyperglycemia only
• Have prominent postprandial hyperglycemia and can tolerate GI side effects
• Require rapid insulin correction for DKA
• Are children under 6 years for type 1 diabetes

Correct Answer: Have prominent postprandial hyperglycemia and can tolerate GI side effects

Q26. Which statement regarding acarbose metabolism is correct?

• It is extensively metabolized to active metabolites in the liver
• Gut bacteria can metabolize acarbose and it is largely excreted in feces
• It is converted to an active insulin secretagogue
• It is unmetabolized and excreted unchanged in urine

Correct Answer: Gut bacteria can metabolize acarbose and it is largely excreted in feces

Q27. Which clinical scenario warrants immediate discontinuation of acarbose?

• Transient mild flatulence during first week
• Development of severe diarrhea with evidence of colitis
• Modest reduction in postprandial glucose
• Minor transient transaminase elevation less than 1.5× ULN

Correct Answer: Development of severe diarrhea with evidence of colitis

Q28. Acarbose’s brand names include:

• Metformin and Januvia
• Precose and Glucobay
• Insulin lispro and Humulin
• Sitagliptin and Saxagliptin

Correct Answer: Precose and Glucobay

Q29. For a patient on acarbose experiencing hypoglycemia at home, which household remedy is appropriate?

• Table sugar (sucrose) dissolved in water
• Fruit jam containing sucrose
• Glucose tablets or gel
• Starch-based bread only

Correct Answer: Glucose tablets or gel

Q30. Which therapeutic advantage does acarbose offer compared with rapid-acting insulin for postprandial control?

• Produces stronger hypoglycemic episodes
• Oral administration targeting gut enzymes with lower risk of systemic hypoglycemia when used alone
• Requires intravenous administration
• Causes significant weight gain enhancing efficacy

Correct Answer: Oral administration targeting gut enzymes with lower risk of systemic hypoglycemia when used alone

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com