QUESTRAN LIGHT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for QUESTRAN LIGHT (QUESTRAN LIGHT).
Binds bile acids in the intestine, forming an insoluble complex that is excreted in feces, thereby reducing enterohepatic circulation of bile acids and promoting conversion of cholesterol to bile acids in the liver.
| Metabolism | Not absorbed systemically; no metabolic pathway. |
| Excretion | Primarily fecal (as resin-bound bile acids); less than 0.05% renally excreted unchanged. |
| Half-life | Not applicable; cholesteryamine resin is not absorbed systemically; half-life refers to GI transit time (~2-4 hours). |
| Protein binding | Not applicable; non-absorbed resin, no protein binding in plasma. |
| Volume of Distribution | Not applicable; no systemic absorption (confined to GI lumen). |
| Bioavailability | 0% oral bioavailability; not absorbed from GI tract. |
| Onset of Action | Lipid reduction: 24-48 hours for bile acid binding; maximal LDL reduction in 2-4 weeks. |
| Duration of Action | LDL reduction persists as long as dosing continues; effect wanes within 1-2 weeks after discontinuation. |
| Molecular Weight | 1600 |
4 grams (one packet or one level scoop) orally once or twice daily, with a maximum of 24 grams per day. Dose may be increased by 4 grams daily at weekly intervals as needed.
| Dosage form | POWDER |
| Renal impairment | No specific dose adjustments are recommended for renal impairment based on GFR. However, use with caution in patients with renal insufficiency due to potential for hyperchloremic acidosis. |
| Liver impairment | No specific dose adjustments based on Child-Pugh score. Caution in patients with hepatic impairment due to potential for fat-soluble vitamin deficiency. |
| Pediatric use | For children, the usual starting dose is 240 mg/kg/day (based on the anhydrous cholestyramine resin) in 2 to 3 divided doses, with subsequent titration based on response. Maximum dose is 8 grams/day. |
| Geriatric use | No specific dose adjustments. Elderly patients may be more susceptible to gastrointestinal adverse effects and constipation; consider starting at lower doses and titrate slowly. Monitor for fluid and electrolyte imbalances. |
| 1st trimester | Not absorbed systemically; considered safe. No known teratogenic risk. |
| 2nd trimester | Not absorbed systemically; considered safe. May interfere with fat-soluble vitamin absorption; supplementation may be needed. |
| 3rd trimester | Not absorbed systemically; considered safe. May interfere with fat-soluble vitamin absorption and exacerbate constipation; supplementation may be needed. |
Clinical note
Comprehensive clinical and safety monograph for QUESTRAN LIGHT (QUESTRAN LIGHT).
| Placental transfer | Minimal to none; drug is not absorbed systemically due to quaternary ammonium structure and high molecular weight. |
| Breastfeeding | Not absorbed systemically, minimal excretion into breast milk expected. Use caution due to theoretical risk of maternal vitamin deficiency affecting milk composition. Monitor infant for potential gastrointestinal effects. |
■ FDA Black Box Warning
None.
| Serious Effects |
Complete biliary obstructionHypersensitivity to cholestyramine or any component
| Precautions | May cause hyperchloremic metabolic acidosis in high doses, May impair absorption of fat-soluble vitamins (A, D, E, K), May reduce absorption of other drugs; administer other drugs at least 1 hour before or 4-6 hours after Questran Light, Use with caution in patients with gastrointestinal motility disorders |
| Food/Dietary | Fat-soluble vitamins (A, D, E, K) may be malabsorbed; consider supplementation with water-miscible forms. High-fiber foods can reduce effectiveness; take with low-fiber beverages. Avoid concurrent intake of high-fat meals that may slow gastric emptying. |
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| Lactation Rating | L3 - Moderately Safe |
| Teratogenic Risk | FDA Pregnancy Category C. No evidence of teratogenicity in animal studies. In pregnant women, cholestyramine may reduce absorption of fat-soluble vitamins (A, D, E, K) and folic acid, potentially leading to fetal deficiency. Use only if clearly needed, with vitamin supplementation. |
| Fetal Monitoring | Monitor serum levels of fat-soluble vitamins (A, D, E, K), folic acid, and prothrombin time. Assess fetal growth via ultrasound. Monitor for constipation and gastrointestinal symptoms. |
| Fertility Effects | No known direct effect on fertility. Potential for nutrient malabsorption (fat-soluble vitamins) could indirectly affect reproductive function if deficiency occurs. |
| Clinical Pearls |
| QUESTRAN LIGHT (cholestyramine) is a bile-acid sequestrant used to lower LDL cholesterol. Administer at least 4 hours apart from other medications to reduce interference with absorption. Monitor for constipation; increase fiber and fluids. Can cause hypertriglyceridemia; check triglycerides before and during therapy. Effective for pruritus due to partial biliary obstruction or primary biliary cholangitis. |
| Patient Advice | Mix powder with at least 4–6 ounces of liquid (water, juice, milk) and stir until fully dissolved; do not take dry. · Take with meals to enhance binding of bile acids. · Drink plenty of fluids and eat high-fiber foods to prevent constipation. · Separate from other medications by at least 4 hours. · May cause bloating, gas, or stomach upset; contact doctor if severe constipation or new muscle pain occurs. |