Bile Acid Sequestrants Are the Only Safe Cholesterol-Lowering Medications During Breastfeeding
Bile acid sequestrants (cholestyramine, colestipol, or colesevelam) are the only pharmacological agents recommended for lowering cholesterol during breastfeeding, as they are not systemically absorbed and do not pass into breast milk in significant amounts. 1, 2, 3
Why Bile Acid Sequestrants Are Safe
These medications work locally in the intestine by binding bile acids and preventing their reabsorption, which forces the liver to convert more cholesterol into bile acids, thereby lowering LDL cholesterol levels. 2
Because they are not absorbed systemically, they pose minimal risk to the breastfed infant and do not interfere with the synthesis of biologically active substances derived from cholesterol that could potentially harm the infant. 2
The American College of Cardiology and European Society of Cardiology both explicitly state these agents are considered safe during lactation. 1, 3
Specific Dosing Options
Cholestyramine: 8-16 g/day orally, divided into 2 doses, providing approximately 10-20% LDL cholesterol reduction. 1
Colestipol: 2-16 g/day orally, given once or in divided doses, with doses of 10-15 g providing 22-27% LDL cholesterol reduction. 1
Colesevelam: 6 tablets (3.75 g) orally once daily or 3 tablets twice daily with meals, providing approximately 15% LDL cholesterol reduction. 1
Critical Monitoring Requirements
Monitor for vitamin K deficiency, as bile acid sequestrants can interfere with absorption of fat-soluble vitamins (A, D, E, K) and folate. 1, 2, 3
Administer oral vitamin supplements at least 4 hours before or after the bile acid sequestrant to prevent binding and malabsorption. 1
For women on warfarin, monitor INR frequently during initiation and periodically thereafter, as bile acid sequestrants can decrease warfarin absorption. 1
Medications That Must Be Avoided
All statins are contraindicated during breastfeeding because their safety has not been proven, and temporary interruption poses no significant disadvantage to the mother. 3
Ezetimibe, PCSK9 inhibitors (alirocumab, evolocumab), bempedoic acid, fibrates, and niacin should all be avoided during lactation due to insufficient safety data or potential risk to the breastfed infant. 1, 2, 3
Managing Drug Interactions
Administer other medications at least 4 hours before bile acid sequestrants to prevent binding and reduced absorption. 1
Specific medications requiring careful timing include oral contraceptives, thyroid replacement therapy, cyclosporine, phenytoin, and sulfonylureas. 1
If the patient is taking metformin, monitor glycemic control closely, as cholestyramine may increase metformin exposure. 1
Common Side Effects and Management
The most common adverse effects are constipation, dyspepsia, and nausea, which can often be managed by starting with lower doses and gradually titrating upward. 1
Colesevelam tablets may be better tolerated than cholestyramine or colestipol powder formulations due to improved palatability and convenience. 1
Special Considerations for Severe Cases
For women with homozygous familial hypercholesterolemia (HoFH) and established atherosclerotic cardiovascular disease, lipoprotein apheresis should be considered during breastfeeding as a non-pharmacological alternative. 2
For severe heterozygous familial hypercholesterolemia (HeFH) with lipoprotein(a) ≥125 nmol/L, lipoprotein apheresis may also be appropriate. 2
When to Resume Other Therapies
Lipid-lowering therapy with statins or other systemically absorbed agents may be resumed after completion of breastfeeding, allowing mothers to breastfeed for their desired duration while managing cardiovascular risk appropriately afterward. 1, 3
Women should be counseled before delivery about the plan to use bile acid sequestrants during lactation and when to transition back to their previous cholesterol-lowering regimen. 2