Cholestyramine MCQs With Answer

Cholestyramine MCQs With Answer

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Cholestyramine MCQs With Answer: Cholestyramine is a prototype bile acid sequestrant widely used in managing hypercholesterolemia and bile salt–induced pruritus. This focused set of MCQs for B. Pharm students covers mechanism of action, ion‑exchange resin chemistry, pharmacokinetics, dosing, adverse effects (constipation, fat‑soluble vitamin malabsorption), clinically important drug interactions (levothyroxine, warfarin, digitalis), contraindications, and monitoring. Questions emphasize applied knowledge: formulation and administration, impact on LDL and triglycerides, hepatic cholesterol metabolism, and strategies to minimize interactions. Study these clinically relevant points to improve exam performance and patient counseling. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary mechanism of action of cholestyramine?

  • Binds bile acids in the intestine to interrupt enterohepatic circulation
  • Inhibits HMG‑CoA reductase in the liver
  • Activates lipoprotein lipase to increase triglyceride clearance
  • Blocks intestinal cholesterol absorption via NPC1L1 inhibition

Correct Answer: Binds bile acids in the intestine to interrupt enterohepatic circulation

Q2. Which pharmacological class does cholestyramine belong to?

  • HMG‑CoA reductase inhibitor
  • Bile acid sequestrant (anion‑exchange resin)
  • PCSK9 inhibitor
  • Fibrate

Correct Answer: Bile acid sequestrant (anion‑exchange resin)

Q3. Which lipid parameter is most reliably reduced by cholestyramine therapy?

  • Triglycerides
  • LDL cholesterol
  • Fasting glucose
  • VLDL particle number

Correct Answer: LDL cholesterol

Q4. What is a common gastrointestinal adverse effect of cholestyramine?

  • Severe diarrhea
  • Klebsiella overgrowth
  • Constipation and bloating
  • Pancreatitis

Correct Answer: Constipation and bloating

Q5. How should cholestyramine be administered for optimal effect and safety?

  • Take dry capsules swallowed with a glass of water
  • Mix powder with water or non‑carbonated beverage and drink immediately
  • Inject intramuscularly once daily
  • Take with a high‑fat meal only

Correct Answer: Mix powder with water or non‑carbonated beverage and drink immediately

Q6. Which of the following drugs has its absorption significantly reduced if taken simultaneously with cholestyramine?

  • Insulin
  • Levothyroxine
  • IV heparin
  • Acetaminophen (paracetamol)

Correct Answer: Levothyroxine

Q7. What is a major contraindication to cholestyramine therapy?

  • Active peptic ulcer disease
  • Complete biliary obstruction
  • Type 1 diabetes mellitus
  • Hypothyroidism

Correct Answer: Complete biliary obstruction

Q8. Which vitamins may have reduced absorption during prolonged cholestyramine use?

  • Water‑soluble vitamins B1 and B12
  • Fat‑soluble vitamins A, D, E, K
  • Vitamin C only
  • Vitamin B6 and folic acid

Correct Answer: Fat‑soluble vitamins A, D, E, K

Q9. Why does cholestyramine lower plasma LDL cholesterol?

  • Directly oxidizes LDL particles in plasma
  • Increases hepatic conversion of cholesterol to bile acids and upregulates LDL receptors
  • Stimulates intestinal excretion of LDL via P‑glycoprotein
  • Inhibits CETP (cholesteryl ester transfer protein)

Correct Answer: Increases hepatic conversion of cholesterol to bile acids and upregulates LDL receptors

Q10. Which statement about systemic absorption of cholestyramine is correct?

  • It is extensively absorbed and undergoes hepatic metabolism
  • It is minimally absorbed; acts locally in the gastrointestinal tract
  • It is converted to an active metabolite in plasma
  • It crosses the blood–brain barrier and affects CNS cholesterol

Correct Answer: It is minimally absorbed; acts locally in the gastrointestinal tract

Q11. What is the recommended spacing when administering other oral medications with cholestyramine to avoid interaction?

  • No spacing needed; take together for better binding
  • Give other medications at least 1 hour before or 4–6 hours after cholestyramine
  • Take other drugs 24 hours after cholestyramine only
  • Double the dose of the concomitant drug when coadministered

Correct Answer: Give other medications at least 1 hour before or 4–6 hours after cholestyramine

Q12. How does cholestyramine affect triglyceride levels in some patients?

  • Consistently lowers triglycerides by 50%
  • Has no effect on triglycerides
  • May increase triglyceride levels in susceptible patients
  • Permanently eliminates triglyceride synthesis

Correct Answer: May increase triglyceride levels in susceptible patients

Q13. For which non‑lipid indication is cholestyramine clinically useful?

  • Treatment of gout
  • Management of pruritus in cholestatic liver disease
  • Antimicrobial therapy for C. difficile colitis
  • Prophylaxis of deep vein thrombosis

Correct Answer: Management of pruritus in cholestatic liver disease

Q14. Which chemical feature characterizes cholestyramine resin?

  • Neutral hydrophobic polymer with sulfonate groups
  • Positively charged quaternary ammonium anion‑exchange resin
  • Chelating agent that binds divalent cations
  • Small molecular weight sugar derivative

Correct Answer: Positively charged quaternary ammonium anion‑exchange resin

Q15. What effect does cholestyramine have on hepatic cholesterol synthesis?

  • Decreases HMG‑CoA reductase activity and reduces cholesterol synthesis
  • Has no impact on hepatic cholesterol synthase pathways
  • Increases hepatic cholesterol synthesis via upregulation of HMG‑CoA reductase
  • Blocks squalene epoxidase directly

Correct Answer: Increases hepatic cholesterol synthesis via upregulation of HMG‑CoA reductase

Q16. Which patient scenario is least appropriate for cholestyramine therapy?

  • Primary hypercholesterolemia with elevated LDL and normal TG
  • Severe hypertriglyceridemia (e.g., TG > 400 mg/dL)
  • Pruritus due to obstructive cholestasis after ruling out contraindication
  • Adjunct therapy when statin intolerance limits options

Correct Answer: Severe hypertriglyceridemia (e.g., TG > 400 mg/dL)

Q17. Which laboratory parameter is most important to monitor after initiating cholestyramine?

  • Serum creatine kinase (CK)
  • Lipid profile, especially LDL cholesterol
  • Arterial blood gas
  • Serum amylase

Correct Answer: Lipid profile, especially LDL cholesterol

Q18. What is the onset time to observe a measurable LDL lowering effect after starting cholestyramine?

  • Within a few hours
  • Within 1 week with progressive improvement over weeks
  • After 1 year of therapy only
  • Immediately after the first dose

Correct Answer: Within 1 week with progressive improvement over weeks

Q19. How does cholestyramine interrupt the enterohepatic circulation of bile acids?

  • By enhancing bile acid synthesis in the intestine
  • By covalently modifying bile acids inside hepatocytes
  • By irreversible enzymatic degradation of bile acids
  • By binding bile acids in the gut and preventing reabsorption

Correct Answer: By binding bile acids in the gut and preventing reabsorption

Q20. Which counseling point helps minimize cholestyramine’s interaction with oral drugs?

  • Always take all medicines together with cholestyramine for synergy
  • Separate dosing times; take interacting drugs 1 hour before or 4–6 hours after
  • Crush tablets and mix with cholestyramine powder to enhance absorption
  • Double doses of interacting drugs when taken with cholestyramine

Correct Answer: Separate dosing times; take interacting drugs 1 hour before or 4–6 hours after

Q21. Which formulation is cholestyramine commonly supplied as?

  • Intravenous solution
  • Oral powder for suspension
  • Transdermal patch
  • Immediate‑release tablet

Correct Answer: Oral powder for suspension

Q22. Which physiochemical property of bile acids enables cholestyramine binding?

  • Bile acids are positively charged and bind to negative resin sites
  • Bile acids are neutral molecules that partition into resin hydrophobic pockets
  • Bile acids are negatively charged (anionic) and bind to positively charged resin
  • Bile acids are gaseous at body temperature and trapped by resin pores

Correct Answer: Bile acids are negatively charged (anionic) and bind to positively charged resin

Q23. Combining cholestyramine with a statin commonly results in which outcome?

  • Antagonism leading to increased LDL
  • No additional lipid‑lowering effect
  • Additive or synergistic LDL lowering
  • Complete reversal of statin action

Correct Answer: Additive or synergistic LDL lowering

Q24. In which of the following clinical situations is cholestyramine particularly useful for symptomatic relief?

  • Lowering acute blood pressure
  • Relief of bile salt–mediated pruritus in cholestasis
  • Immediate reduction of serum potassium
  • Treatment of acute bacterial meningitis

Correct Answer: Relief of bile salt–mediated pruritus in cholestasis

Q25. Which monitoring or supplementation may be considered during long‑term cholestyramine therapy?

  • Supplementation with fat‑soluble vitamins if deficiency develops
  • No monitoring needed due to lack of systemic effects
  • Routine erythropoietin injections
  • High‑dose vitamin C supplementation only

Correct Answer: Supplementation with fat‑soluble vitamins if deficiency develops

Q26. Which statement about cholestyramine and pregnancy is most accurate?

  • It is absolutely contraindicated in all trimesters
  • It is a nonabsorbable resin; use only if benefits justify potential risks (FDA category C)
  • It is the first‑line lipid‑lowering drug in pregnancy
  • It is an FDA category X drug and causes fetal malformations

Correct Answer: It is a nonabsorbable resin; use only if benefits justify potential risks (FDA category C)

Q27. Which of the following is a pharmacokinetic consequence of cholestyramine binding to drugs in the gut?

  • Increased oral bioavailability of the coadministered drug
  • Reduced absorption and decreased plasma concentrations of the coadministered drug
  • Enhanced renal clearance of the coadministered drug
  • Conversion of the coadministered drug into an active metabolite

Correct Answer: Reduced absorption and decreased plasma concentrations of the coadministered drug

Q28. Which structural characteristic of cholestyramine determines its bile acid binding capacity?

  • Presence of quaternary ammonium groups that exchange chloride for bile acids
  • Polyethylene glycol chains that dissolve bile acids chemically
  • Peptide backbone that enzymatically degrades bile salts
  • Metal chelation centers that bind bile acids tightly

Correct Answer: Presence of quaternary ammonium groups that exchange chloride for bile acids

Q29. How should a pharmacist advise a patient who is prescribed both cholestyramine and warfarin?

  • Continue warfarin unchanged and take both drugs together for best effect
  • Separate dosing times and monitor INR closely due to possible altered warfarin absorption
  • Discontinue warfarin whenever starting cholestyramine
  • Double the warfarin dose while on cholestyramine without monitoring

Correct Answer: Separate dosing times and monitor INR closely due to possible altered warfarin absorption

Q30. Which description best summarizes cholestyramine’s therapeutic classification?

  • A systemically absorbed enzyme inhibitor that reduces cholesterol synthesis
  • An oral, nonabsorbable anion‑exchange resin that binds bile acids to lower LDL
  • A monoclonal antibody that increases LDL receptor degradation
  • An injectable peptide that blocks intestinal fat absorption

Correct Answer: An oral, nonabsorbable anion‑exchange resin that binds bile acids to lower LDL

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