Maximum Recommended Dose of Questran (Cholestyramine)
The maximum recommended daily dose of Questran (cholestyramine) is 24 grams of anhydrous cholestyramine resin, which is equivalent to 6 pouches or 6 scoopfuls of the powder formulation. 1
Dosing Guidelines
Initial and Maintenance Dosing
- Starting dose: 1 pouch or 1 level scoopful (4 grams of anhydrous cholestyramine resin) once or twice daily 1
- Maintenance dose: 2 to 4 pouches or scoopfuls daily (8 to 16 grams of anhydrous cholestyramine resin) divided into two doses 1
- Maximum dose: 6 pouches or scoopfuls daily (24 grams of anhydrous cholestyramine resin) 1
Administration Recommendations
- Dose increases should be gradual with periodic assessment of lipid/lipoprotein levels at intervals of not less than 4 weeks 1
- Although the recommended dosing schedule is twice daily, cholestyramine may be administered in 1 to 6 doses per day 1
- Should be taken with meals 2, 1
- Must be mixed with water or other non-carbonated beverages (at least 2-3 ounces) before ingestion; can also be mixed with highly fluid soups or pulpy fruits 1
Clinical Considerations
Efficacy
- Cholestyramine monotherapy provides approximately 10.4% reduction in LDL-C versus placebo 2
- In dose-ranging studies, higher doses correlate with greater LDL-C reduction:
- 5g: 16.3% reduction
- 10g: 22.8% reduction
- 15g: 27.2% reduction 2
Tolerability and Adherence
- Higher doses may be associated with increased side effects and reduced adherence 2
- Common adverse effects include constipation, dyspepsia, and nausea 2
- In pediatric studies, adverse effects included foul taste (73%), nausea with bloating (18%), and constipation 3
- Long-term adherence can be challenging due to palatability and side effects 3
Special Dosing Considerations
- For patients who cannot tolerate the full volume of a single dose, dividing into smaller, more frequent doses may improve tolerability 4
- For doses of 24g per day, dividing the dose in half and administering twice daily may be more practical due to the bulk involved 4
- No dosage adjustment is needed in chronic kidney disease 2
Important Drug Interactions
- Drugs with potential interaction should be taken at least 1 hour before or 4 hours after cholestyramine to avoid impeding their absorption 2
- Known interactions with cyclosporin, oral contraceptives, olmesartan, phenytoin, sulfonylureas, thyroid replacement therapy, and warfarin 2
- May increase exposure to metformin; monitor glycemic control in diabetic patients 2
Long-term Monitoring
- Monitor for potential nutritional deficiencies, particularly fat-soluble vitamins and folate 5
- Consider supplementation with folic acid for patients on long-term therapy 5
- Monitor triglyceride levels, as cholestyramine may increase serum triglycerides in some patients 2
Cholestyramine's effectiveness must be balanced against its side effect profile and impact on medication absorption. Starting at lower doses and gradually titrating up to the maximum of 24 grams daily based on clinical response and tolerability represents the optimal approach to maximize both efficacy and adherence.