QUESTRAN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for QUESTRAN (QUESTRAN).
Binds bile acids in the intestine, forming an insoluble complex that is excreted in feces, thereby preventing their enterohepatic reabsorption and increasing hepatic LDL receptor activity and cholesterol catabolism.
| Metabolism | Not absorbed systemically; acts locally in the gastrointestinal tract. |
| Excretion | Cholestyramine is not absorbed from the gastrointestinal tract; therefore, it is excreted entirely in the feces as the intact resin, with no renal or biliary excretion. |
| Half-life | Not applicable; the drug is not absorbed and does not have a systemic half-life. Clinical effect persists as long as the resin remains in the gut (approximately 6-8 hours per dose). |
| Protein binding | 0% (not absorbed, thus no systemic protein binding). The resin binds bile acids in the gut lumen. |
| Volume of Distribution | Not applicable; the drug is not absorbed and does not distribute into body tissues. Vd is effectively 0 L/kg. |
| Bioavailability | 0% (oral); cholestyramine is a non-absorbable resin, so it does not enter the systemic circulation. |
| Onset of Action | Oral: Reduction in serum LDL-cholesterol is typically observed within 24-48 hours, with maximal effect in 2-4 weeks. |
| Duration of Action | Duration of hypolipidemic effect: 2-4 weeks after initiation of therapy, effect persists as long as dosing continues. Upon discontinuation, serum lipids return to baseline within 1-2 weeks. |
Questran (cholestyramine) is administered orally. The typical adult dose is 4 grams (one packet or one level scoop) once or twice daily, with a maximum of 24 grams per day. The powder should be mixed with at least 120 mL of fluid (e.g., water, juice).
| Dosage form | TABLET |
| Renal impairment | No dose adjustment is required for renal impairment. Cholestyramine is not systemically absorbed. |
| Liver impairment | No dose adjustment is required for hepatic impairment as cholestyramine acts locally in the gastrointestinal tract. |
| Pediatric use | For pediatric patients, the usual dose is 240 mg/kg/day orally in divided doses, not to exceed 8 grams per day. Dosing may be initiated at a lower dose and titrated upward based on response and tolerance. |
| Geriatric use | No specific dose adjustment is indicated for elderly patients. Use the standard adult dose, but consider potential for increased constipation and drug interactions due to polypharmacy. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for QUESTRAN (QUESTRAN).
| Breastfeeding | Not absorbed systemically; unlikely to pass into breast milk. No M/P ratio available. Compatible with breastfeeding. |
| Teratogenic Risk | Pregnancy Category C. Not systemically absorbed; minimal fetal exposure. No teratogenic effects observed in animal studies. Use only if clearly needed. |
| Fetal Monitoring | Monitor for fat-soluble vitamin deficiencies (A, D, E, K) and clotting times in mother and neonate if used long-term. |
■ FDA Black Box Warning
Powder may cause severe esophageal and airway obstruction if inhaled or aspirated. Mix with water or other appropriate liquid before administration.
| Serious Effects |
Complete biliary obstruction; hypersensitivity to cholestyramine resin; severe hypertriglyceridemia (due to potential increase in VLDL).
| Precautions | May cause constipation and impact fecal impaction, especially in elderly; may reduce absorption of fat-soluble vitamins; may interfere with absorption of other drugs, including warfarin, thyroid hormones, and digitalis; hyperchloremic acidosis risk in patients with renal insufficiency. |
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| Fertility Effects | No known effect on fertility. May interfere with absorption of nutrients and medications; correct deficiencies to support reproductive health. |