Can a patient with a history of cardiovascular disease or high cholesterol take a missed dose of colestipol hydrochloride (bile acid sequestrant) with their other medications, such as warfarin (anticoagulant), at bedtime?

No, a Missed Dose of Colestipol Should Not Be Taken with Other Medications at Bedtime

If a patient misses their scheduled dose of colestipol, they should skip that dose entirely rather than taking it at bedtime with other medications, particularly if they are on warfarin. Taking colestipol at bedtime creates two critical problems: it must be taken with food to work properly, and the required 4-hour separation from other medications (especially warfarin) cannot be maintained if taken together. 1, 2, 3

Why Colestipol Cannot Be Taken at Bedtime

Food Requirement is Non-Negotiable

• Colestipol must be taken with meals because it binds bile acids that are released during digestion. 2
• Taking colestipol without food means it cannot interact with bile acids released during the digestive process, rendering the medication ineffective at achieving its lipid-lowering effect. 2
• The American College of Cardiology specifically recommends taking colestipol tablets with a meal and liquid, either 6 tablets once daily or 3 tablets twice daily. 1, 2

Critical Drug Interaction with Warfarin

• Colestipol significantly reduces warfarin absorption and can decrease INR, potentially leading to inadequate anticoagulation and increased thrombotic risk. 1
• The American College of Cardiology mandates that warfarin must be taken at least 1 hour before or 4 hours after colestipol to avoid impaired absorption. 1, 3
• For patients on warfarin, the INR must be monitored frequently during colestipol initiation and then periodically thereafter. 1
• Taking these medications together at bedtime would completely negate warfarin's therapeutic effect and place the patient at serious risk for thrombotic events. 1

Proper Missed Dose Management

Standard Recommendation

• If a dose is missed, the patient should skip that dose and resume their regular schedule at the next meal. 3
• Patients should not double up doses or take colestipol outside of meal times. 2, 3

Optimal Medication Timing Strategy

• Schedule colestipol with breakfast and/or dinner (depending on once-daily vs twice-daily dosing). 2
• Take warfarin and other medications either first thing in the morning (at least 1 hour before colestipol) or at bedtime (at least 4 hours after the last colestipol dose). 2
• This separation ensures both medications work effectively without interference. 1, 2

Additional Medications Requiring Separation

Beyond warfarin, other medications with narrow therapeutic windows that require the same 1-hour-before or 4-hours-after separation include: 1, 3

• Thyroid hormone replacement therapy
• Phenytoin
• Oral contraceptives containing ethinyl estradiol and norethindrone
• Cyclosporine
• Sulfonylureas
• Olmesartan

Common Pitfall to Avoid

• The most dangerous error is assuming a missed dose can be "made up" by taking it at a convenient time without food or proper medication separation. This compromises both the effectiveness of colestipol and the safety of concomitant medications like warfarin. 1, 2, 3
• Patients should be counseled at initiation that strict adherence to meal timing and medication separation is essential for both efficacy and safety. 2, 3