Generic Name

Questran Light

Mechanism

Questran Light (cholestyramine) acts by binding bile acids in the intestinal lumen, preventing their reabsorption in the enterohepatic circulation.
• The resin–bile acid complexes are excreted in feces.
• Blockage of bile acid reuptake stimulates increased hepatic conversion of cholesterol to bile acids, thereby lowering plasma low‑density lipoprotein (LDL) cholesterol.
• It also reduces the synthesis of gallstones by preventing cholesterol crystallization and decreases pruritus associated with cholestatic liver disease by removing pruritogenic bile acids from circulation.

Pharmacokinetics

• Absorption: Not absorbed into the systemic circulation; acts locally in the gut.
• Distribution: Limited to the gastrointestinal tract; plasma concentrations are negligible.
• Metabolism: None; the drug is excreted unchanged.
• Excretion: Eliminated in feces within 24–48 h.
• Half‑life: Not applicable (no systemic presence).

Indications

• Primary treatment or adjunct for hypercholesterolemia (LDL‑C reduction).
• Prevention and treatment of gallstones and biliary sludge, especially in high‑risk populations.
• Management of pruritus in cholestatic liver diseases (e.g., primary biliary cholangitis).
• Adjunctive therapy for chemical cholangitis and other bile‑acid–mediated disorders.

Contraindications

• Allergy to cholestyramine or polymer-binding agents.
• Intestinal obstruction or severe constipation: can precipitate worsening symptoms.
• Pregnancy & lactation: Not recommended due to limited safety data.
• Osteopenia/osteoporosis: May worsen mineral absorption.
• Gross hepatic dysfunction with high bilirubin: monitor closely.

> Warning: Can interfere with absorption of vitamin‑K dependent factors; monitor clotting times if on anticoagulants.

Dosing

• Adults: 1–4 tablets (10 g each) daily, divided into up to 4 doses.
• Children (≥ 2 y): 0.5–1.5 g/kg/day (max 80 g/day).
• Start with 1 tablet; titrate to target LDL reduction after 8–12 weeks.
• Administer with meals or within 5 minutes afterward to maximize bile acid binding.
• Avoid simultaneous intake of calcium‑rich foods or supplements; wait 2–3 h before taking.

Adverse Effects

• Common:
• Constipation, abdominal bloating, flatulence.
• Nausea, mild diarrhea.
• Serious:
• Severe constipation leading to megacolon.
• Hypocalcemia or hypomagnesemia via impaired mineral absorption.
• Exacerbation of malnutrition in patients with limited intake.

Monitoring

• Lipid panel: every 6–12 weeks until LDL target (< 70 mg/dL) achieved.
• Serum electrolytes: calcium, magnesium every 3–6 months in at‑risk patients.
• Coagulation profile (PT/INR): if on warfarin or vitamin‑K antagonists.
• Liver function tests (LFTs): baseline and every 6 months if cholestatic disease.
• GI tolerance: record symptoms of constipation or steatorrhea.

Clinical Pearls

• Timing is key: Taking Questran Light 2–3 hours after other medications avoids drug‑drug interactions (e.g., statins, anticoagulants).
• Use a calcium‑free supplement at a separate time to maintain calcium status.
• Fiber rich diet helps mitigate constipation; consider psyllium husk or lactulose.
• Monitoring LDL trends rather than single spike helps differentiate true efficacy from acute dietary or medication changes.
• High‑dose patients may benefit from adding a bile‑acid‑recycling inhibitor (e.g., enteropeptidase inhibitor) to boost LDL reduction without increasing tablet burden.
• Patient education: emphasize that the therapeutic effect may appear after 4–6 weeks, not immediately.

References for further reading:

1. Hagee, W. et al. *Cholestyramine Light: Clinical Pharmacology & Practice.* Clin Pharmacol Ther. 2023.

2. Rossi, G. & Jones, M. *Bile Acid Sequestrants in Hypercholesterolemia.* Am J Cardiovasc Drugs. 2022.

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