Diazoxide MCQs With Answer

Diazoxide MCQs With Answer

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Introduction

Diazoxide is a potassium‑channel opener with important roles as a vasodilator and hyperglycemic agent. This concise collection of Diazoxide MCQs With Answer is tailored for B. Pharm students to build in‑depth knowledge of mechanism of action, ATP‑sensitive K+ channel modulation, clinical uses (insulinoma, congenital hyperinsulinism, hypertensive crisis), adverse effects (hyperglycemia, edema, hirsutism), dosing considerations, formulations and key drug interactions. Questions probe pharmacodynamics, therapeutic monitoring, contraindications and neonatal therapy to strengthen conceptual understanding and exam readiness. Topics include indications, contraindications, adverse reactions, monitoring, dosage forms, drug interactions and neonatal use — essential for exams and practical pharmacy practice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which is the primary mechanism by which diazoxide reduces insulin release?

  • Activation of insulin receptor tyrosine kinase
  • Inhibition of voltage‑gated calcium channels
  • Opening of ATP‑sensitive potassium channels in pancreatic beta‑cells
  • Blocking GLUT2 glucose uptake

Correct Answer: Opening of ATP‑sensitive potassium channels in pancreatic beta‑cells

Q2. Diazoxide is clinically indicated for which of the following conditions?

  • Type 1 diabetes mellitus
  • Insulinoma and congenital hyperinsulinism
  • Hypotension due to adrenal insufficiency
  • Hyperthyroidism

Correct Answer: Insulinoma and congenital hyperinsulinism

Q3. What major cardiovascular effect can diazoxide produce due to vascular smooth muscle KATP channel opening?

  • Bradycardia without change in blood pressure
  • Peripheral vasodilation and hypotension
  • Increased systemic vascular resistance
  • Coronary artery vasospasm

Correct Answer: Peripheral vasodilation and hypotension

Q4. Which adverse effect is characteristically associated with prolonged diazoxide therapy?

  • Hypertrichosis (excessive hair growth)
  • Severe hypoglycemia
  • Osteoporosis
  • Pulmonary fibrosis

Correct Answer: Hypertrichosis (excessive hair growth)

Q5. Which monitoring parameter is essential when a patient is treated with diazoxide for hyperinsulinism?

  • Plasma sodium only
  • Blood glucose and blood pressure
  • Serum bilirubin levels
  • Serum amylase

Correct Answer: Blood glucose and blood pressure

Q6. Which drug interaction is most clinically relevant with diazoxide?

  • Synergistic hypoglycemia with sulfonylureas
  • Antagonism of insulin and oral hypoglycemic agents
  • Enhanced anticoagulant effect with warfarin
  • Increased sedation with benzodiazepines

Correct Answer: Antagonism of insulin and oral hypoglycemic agents

Q7. In neonates with congenital hyperinsulinism, diazoxide is used primarily to:

  • Stimulate insulin secretion
  • Suppress insulin secretion and raise blood glucose
  • Act as a glucagon substitute
  • Enhance pancreatic beta‑cell proliferation

Correct Answer: Suppress insulin secretion and raise blood glucose

Q8. Which adverse effect of diazoxide is related to renal sodium retention?

  • Hyperglycemia
  • Fluid retention and edema
  • Rash
  • Peripheral neuropathy

Correct Answer: Fluid retention and edema

Q9. Which concomitant therapy is often used to reduce diazoxide‑induced fluid retention?

  • Loop diuretic like furosemide
  • Thiazide diuretic such as hydrochlorothiazide
  • ACE inhibitor immediately on start
  • Potassium supplementation

Correct Answer: Thiazide diuretic such as hydrochlorothiazide

Q10. Diazoxide is contraindicated or should be used cautiously in patients with which tumor?

  • Pituitary adenoma
  • Pheochromocytoma
  • Basal cell carcinoma
  • Hepatocellular carcinoma

Correct Answer: Pheochromocytoma

Q11. The hyperglycemic action of diazoxide is due to its effect on pancreatic beta‑cell membrane potential causing:

  • Depolarization and increased calcium influx
  • Hyperpolarization and reduced calcium influx
  • Activation of adenylate cyclase to increase cAMP
  • Inhibition of insulin mRNA synthesis

Correct Answer: Hyperpolarization and reduced calcium influx

Q12. Which of the following is a common metabolic laboratory abnormality associated with diazoxide therapy?

  • Severe hypokalemia without edema
  • Hyperglycemia due to decreased insulin secretion
  • Marked hypercalcemia
  • Hypouricemia

Correct Answer: Hyperglycemia due to decreased insulin secretion

Q13. Which formulation routes are available for diazoxide in clinical practice?

  • Topical and inhalational
  • Oral and intravenous
  • Intramuscular only
  • Transdermal patch only

Correct Answer: Oral and intravenous

Q14. Which mechanism explains why diazoxide may cause reflex tachycardia?

  • Direct stimulation of the sinoatrial node
  • Reflex sympathetic activation secondary to hypotension
  • Blocking parasympathetic innervation of the heart
  • Increasing blood viscosity

Correct Answer: Reflex sympathetic activation secondary to hypotension

Q15. Compared with octreotide for congenital hyperinsulinism, diazoxide acts primarily by:

  • Directly inhibiting somatostatin receptors
  • Opening KATP channels to reduce insulin release
  • Increasing glucagon secretion
  • Blocking insulin receptors

Correct Answer: Opening KATP channels to reduce insulin release

Q16. Which patient population requires careful dosing and monitoring when using diazoxide?

  • Patients with controlled asthma
  • Neonates and infants with hyperinsulinism
  • Young adults with seasonal allergies
  • Patients receiving topical corticosteroids

Correct Answer: Neonates and infants with hyperinsulinism

Q17. A serious but less common adverse effect of diazoxide that mandates immediate evaluation is:

  • Progressive weight loss
  • Congestive heart failure secondary to fluid overload
  • Dry cough without dyspnea
  • Mild transient anemia

Correct Answer: Congestive heart failure secondary to fluid overload

Q18. When treating insulinoma with diazoxide, what therapeutic goal is primarily pursued?

  • Increase insulin levels to prevent weight loss
  • Suppress inappropriate insulin secretion and prevent hypoglycemia
  • Stimulate glucagon to reduce insulin effects
  • Reduce tumor size directly

Correct Answer: Suppress inappropriate insulin secretion and prevent hypoglycemia

Q19. Which adverse metabolic effect may require insulin therapy adjustment in diabetic patients receiving diazoxide?

  • Increased insulin sensitivity leading to hypoglycemia
  • Marked hyperglycemia requiring increased antidiabetic dosing
  • Unchanged glucose levels with no adjustment
  • Hypoglycemia due to pancreatic beta‑cell proliferation

Correct Answer: Marked hyperglycemia requiring increased antidiabetic dosing

Q20. Which of the following best describes the pharmacological class of diazoxide?

  • Beta‑adrenergic agonist
  • ATP‑sensitive potassium channel opener and vasodilator
  • Calcium channel blocker of L‑type channels
  • Sulfonylurea insulin secretagogue

Correct Answer: ATP‑sensitive potassium channel opener and vasodilator

Q21. A physician prescribes diazoxide for a patient with severe hypoglycemia from an insulinoma. Which baseline assessment is most important?

  • Cardiac function and blood pressure assessment
  • Audiometry testing
  • Fasting lipid profile
  • Visual acuity testing

Correct Answer: Cardiac function and blood pressure assessment

Q22. Which of the following best explains why thiazide diuretics are sometimes co‑prescribed with diazoxide?

  • Thiazides potentiate diazoxide’s hyperglycemic action
  • Thiazides reduce diazoxide‑induced fluid retention and edema
  • Thiazides block diazoxide metabolism in the liver
  • Thiazides increase renal excretion of diazoxide

Correct Answer: Thiazides reduce diazoxide‑induced fluid retention and edema

Q23. Long‑term diazoxide therapy can lead to which endocrine change?

  • Persistent hypoglycemia due to insulin upregulation
  • Chronic hyperglycemia from reduced insulin release
  • Adrenal suppression
  • Hyperprolactinemia

Correct Answer: Chronic hyperglycemia from reduced insulin release

Q24. In which scenario should diazoxide be used with extreme caution or avoided?

  • Patient with severe heart failure and fluid overload
  • Patient with mild seasonal allergic rhinitis
  • Young adult with migraine history
  • Patient receiving topical antifungal therapy

Correct Answer: Patient with severe heart failure and fluid overload

Q25. Which pharmacodynamic property explains diazoxide’s effect on both blood pressure and glucose?

  • Selective inhibition of alpha‑1 receptors
  • Nonselective blockade of sodium channels
  • Opening of KATP channels in vascular smooth muscle and pancreatic beta‑cells
  • Stimulation of pituitary growth hormone release

Correct Answer: Opening of KATP channels in vascular smooth muscle and pancreatic beta‑cells

Q26. Which adverse laboratory monitoring is appropriate during diazoxide therapy?

  • Frequent monitoring of serum glucose, electrolytes and renal function
  • Monthly liver biopsy
  • No monitoring is required
  • Only annual chest X‑ray

Correct Answer: Frequent monitoring of serum glucose, electrolytes and renal function

Q27. Which statement about diazoxide onset and duration is most appropriate for clinical use?

  • It has an immediate onset and ultra‑short duration requiring continuous infusion
  • It has relatively rapid onset when IV and a prolonged duration that may allow intermittent dosing
  • It requires intramuscular depot dosing weekly
  • It only works after several weeks of administration

Correct Answer: It has relatively rapid onset when IV and a prolonged duration that may allow intermittent dosing

Q28. Which symptom in a patient on diazoxide should prompt immediate discontinuation and urgent evaluation?

  • Mild transient headache
  • Rapid weight gain with dyspnea suggestive of heart failure
  • Temporary mild nausea
  • Occasional muscle cramps

Correct Answer: Rapid weight gain with dyspnea suggestive of heart failure

Q29. For B. Pharm students, which key counselling point is essential when dispensing diazoxide?

  • Advise patient that hypoglycemia is the most likely side effect
  • Explain the risk of hyperglycemia, fluid retention and need for blood glucose/BP monitoring
  • Recommend taking with grapefruit juice to increase absorption
  • No monitoring or follow‑up is necessary

Correct Answer: Explain the risk of hyperglycemia, fluid retention and need for blood glucose/BP monitoring

Q30. In pharmacotherapy exam questions, diazoxide is best compared to which class for its insulin‑suppressing effect?

  • Sulfonylureas, because both increase insulin release
  • Somatostatin analogs, because both can reduce insulin effects but by different mechanisms
  • Biguanides, because both enhance insulin sensitivity
  • GLP‑1 agonists, because both stimulate insulin secretion

Correct Answer: Somatostatin analogs, because both can reduce insulin effects but by different mechanisms

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