Cholestyramine: a straight-talk guide on what it does and how to use it

Cholestyramine is a medicine that works inside your gut to bind bile acids. You’ll see it used to lower LDL cholesterol, treat diarrhea caused by bile salt malabsorption, and ease itching from certain liver problems. It isn’t absorbed into the bloodstream, so most effects are local to the digestive tract.

How cholestyramine works and common uses

Cholestyramine grabs bile acids in the intestine and prevents them from being reabsorbed. Your liver then pulls cholesterol from the blood to make more bile, which lowers LDL ("bad") cholesterol over time. Doctors also use it when bile acids spill into the colon and cause diarrhea, or to reduce itching when bile flow is blocked.

It usually comes as a powder that you mix with water or a noncarbonated drink. Tablets exist but the powder is common. Typical starting doses are 4 grams once or twice daily and your provider may increase the dose. Daily totals can run up to about 24 grams, but follow the exact plan your prescriber gives you.

Safety tips, side effects, and drug interactions

Most people get mild digestive side effects: constipation, bloating, gas, or stomach discomfort. If you become severely constipated, have new severe belly pain, or can’t pass stool, contact your doctor. Cholestyramine can also reduce absorption of fat-soluble vitamins (A, D, E, K) and certain minerals, so long-term use may require monitoring or supplements.

Drug timing matters. Because cholestyramine binds other medicines, take other pills at least 1 hour before or 4–6 hours after cholestyramine. This helps keep your other medicines working properly. Tell your pharmacist you’re on cholestyramine whenever you get a new prescription.

A few quick cautions: don’t use it if you have complete biliary obstruction or a bowel blockage. It can raise triglyceride levels in some people, so if you already have very high triglycerides your doctor might choose a different treatment. Pregnant or breastfeeding? Talk to your provider — data are limited and they’ll weigh risk versus benefit.

Practical tips: mix the powder into 4–8 ounces of liquid and drink it right away—don’t let it sit. If swallowing is hard, try a thicker drink like applesauce. Start with the lowest prescribed dose and increase slowly to limit gas and bloating. If constipation is an issue, ask about a fiber supplement or stool softener.

When to call your provider: worsening abdominal pain, persistent constipation, dizziness, unexpected bleeding or bruising, or if your skin and eyes turn yellow. Also check with your doctor if your cholesterol or triglyceride numbers change unexpectedly while on therapy.

Questions about how cholestyramine fits into your treatment? Ask your pharmacist or prescriber. A quick medication review can prevent interactions and make this medicine work better for you.