Cholestyramine: what it treats, how to take it, side effects
Last updated September 3, 2026.
Cholestyramine is a bile acid sequestrant - it binds bile acids in the intestines into a product the body removes, and the liver burns cholesterol to make more. You may know it as Questran. A gritty powder with a pre-statin pedigree - and one scheduling rule that runs your day: it kidnaps other medications.
What does it treat?
High cholesterol - lowering the fat-like substance that builds up and clogs blood vessels, the road to heart attacks and strokes.
How do you take it?
A powder mixed with liquid, one to six times a day, before meals and/or at bedtime. Never take it dry: mix with water, juice, or a noncarbonated drink - or stir into applesauce or thin soup. The load-bearing rule: other medications go at least 1 hour before or 4 hours after cholestyramine - the powder binds drugs as happily as bile acids and carries them out of the body unabsorbed. Continue even when you feel well; cholesterol control is a long average. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: the gut set - constipation, bloating, stomach pain, gas, upset stomach, vomiting, diarrhea, loss of appetite, heartburn, and indigestion. Constipation is the one that ends adherence: fluids, fiber, and movement from day one, and report it if it hardens.
- Serious - call your doctor immediately: unusual bleeding - from the gums or the rectum, for example - the sign that fat-soluble vitamin absorption has been disrupted long enough to matter.
Who should not take it?
Anyone with a complete bile duct blockage. Flag constipation problems, hemorrhoids, trouble swallowing, and stomach or intestinal issues. Because it binds other drugs and fat-soluble vitamins, the medication and supplement list is part of the dosing plan - including vitamins A, D, E, and K. If you become pregnant, call your doctor.
When is it an emergency?
Severe stomach pain with vomiting, or black or bloody stools, is urgent care. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
Why do my other pills have to wait around this powder?
Cholestyramine is a binding resin - it grabs bile acids in the gut, and it grabs medications just as readily, sweeping them out before they absorb. MedlinePlus sets the spacing: other medications at least 1 hour before or 4 hours after each dose. Underspaced, your blood-pressure pill or thyroid pill quietly stops working. The schedule is the drug's real skill: anchors at breakfast and dinner, other pills parked an hour away.
Why is it a powder and not a pill?
The effective dose is grams of resin - far too much for a tablet - so it comes as a powder you mix. Never take it dry: it swells on contact with liquid, and dry powder is a choking hazard. Water, juice, or a noncarbonated drink all work; stirring it into applesauce or thin soup is the texture fix for people who hate the grit.
Why the constipation, and what do I do about it?
The resin bulks the stool and slows the gut - constipation, bloating, and gas lead the common list. The countermeasures start day one, not after the problem: fluids, fiber, movement. Constipation that hardens despite those gets reported - the dose or the agent can change, and untreated constipation on a binder can escalate. Hemorrhoids are part of the same conversation.
Why did my doctor mention vitamins?
The resin binds fat-soluble vitamins - A, D, E, K - along with the bile acids, and over months that can deplete them. Vitamin K is the one with the alarm symptom: unusual bleeding, from gums or the rectum, is the call-your-doctor sign. Supplementation, if needed, is your doctor's call - and any supplement joins the spacing schedule like every other pill.
How is cholestyramine different from a statin?
Statins shut down cholesterol production in the liver - systemic, potent, once daily. Cholestyramine never enters the bloodstream: it works entirely inside the gut by hauling bile acids out, forcing the liver to spend cholesterol replacing them. Weaker per unit, but no muscle or liver-enzyme issues, and combinable with a statin when one mechanism is not enough. The price is the powder routine and the scheduling.
What happens if I miss a dose of cholestyramine?
Take it as soon as you remember - keeping the 1-hour spacing from other medications in mind - unless it is almost time for the next one; then skip it and never double up. Cholesterol moves over months, so a missed dose is a rounding error; the spacing rule is not. When in doubt, skip rather than stack your other medications' absorption into jeopardy.