Prescription medication · Bile Acid Sequestrant
cholestyramine
Also sold as Questran. This medicine is used with a diet to lower high cholesterol, especially LDL cholesterol (the "bad" cholesterol).
Data updated 2026-05-15
- 11,539
- FDA reportsModerately reported
- 34
- InteractionsSeveral interactions
- In shortage
- FDA status
What the data shows
cholestyramine (Questran) is a prescription Bile Acid Sequestrant, reported less often than most tracked drugs (11,539 FDA reports), with 34 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
cholestyramine (Questran) is a prescription Bile Acid Sequestrant. This medicine is used with a diet to lower high cholesterol, especially LDL cholesterol (the "bad" cholesterol).
Cholestyramine is a medicine that helps lower high cholesterol levels in your blood. It works by preventing your body from absorbing cholesterol in the intestines.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
cholestyramine is currently listed as to be discontinued by the FDA. Affected manufacturer: Upsher-Smith Laboratories, LLC.
View all drug shortages →Drug Pricing (NADAC)
Generic Price
$0.85/unit
Generic Available
Yes (15 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine is used with a diet to lower high cholesterol, especially LDL cholesterol (the "bad" cholesterol).
Common side effects
Constipation
Key warnings
Since cholestyramine can affect how your body absorbs other medicines, take other drugs at least 1 hour before or 4 to 6 hours after taking cholestyramine.
The sections below are summarized in plain English from cholestyramine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Cholestyramine is a resin that binds to bile acids in your intestines. Bile acids help digest fats, including cholesterol. By binding to bile acids, cholestyramine prevents them from being reabsorbed, so your body uses cholesterol to make more bile acids, which lowers cholesterol levels in your blood.
How to Take It
The usual starting dose is one pouch or scoop (5.7 grams) once or twice a day. The typical maintenance dose is 2 to 4 pouches or scoops daily, divided into two doses. Mix the powder with 2 to 3 ounces of water or another beverage before taking it. You can take it with meals, but you may need to adjust the timing to avoid it interfering with other medicines you take.
This is a plain-language summary of cholestyramine's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or plan to become pregnant. Cholestyramine may affect how you absorb vitamins, so your doctor may recommend supplements. Talk to your doctor about the risks and benefits of taking this medicine while breastfeeding.
This is a plain-language summary of cholestyramine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of cholestyramine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature (68° to 77°F) and keep the lid tightly closed.
Side Effects (from patient reports)
Based on 11,539 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for cholestyramine, by number of reports
- Diarrhea
Diarrhea
1,631 reports
- Tiredness
Tiredness
878 reports
- Feeling sick to your stomach
Feeling sick to your stomach
783 reports
- Joint pain 622
Joint pain
622 reports
- Head pain 543
Head pain
543 reports
- Stomach pain 524
Stomach pain
524 reports
- Throwing up 503
Throwing up
503 reports
- Weight loss 498
Weight loss
498 reports
- Difficulty breathing 488
Difficulty breathing
488 reports
- Pain 476
Pain
476 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for cholestyramine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where cholestyramine sits
cholestyramine has more FDA adverse-event reports than 43% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is cholestyramine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 11,539 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
11,539
Reports Mentioning Death
811
7.0% of reports — not proof of cause
Hospitalization Reports
3,888
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DIARRHOEA | 1,631 |
| 4 | FATIGUE | 877 |
| 5 | NAUSEA | 783 |
| 6 | ARTHRALGIA | 621 |
| 7 | HEADACHE | 543 |
| 8 | ABDOMINAL PAIN | 524 |
| 9 | VOMITING | 503 |
| 10 | WEIGHT DECREASED | 498 |
| 11 | DYSPNOEA | 488 |
| 12 | PAIN | 476 |
| 13 | ASTHENIA | 456 |
| 14 | CONSTIPATION | 390 |
| 15 | MALAISE | 387 |
| 16 | DIZZINESS | 366 |
| 17 | PNEUMONIA | 365 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Since cholestyramine can affect how your body absorbs other medicines, take other drugs at least 1 hour before or 4 to 6 hours after taking cholestyramine.
Known Drug Interactions
Cholestyramine Clinical Impact: Concomitant administration of cholestyramine can delay the absorption of naproxen. Intervention: Concomitant administration of cholestyramine with naproxen tablets or naproxen sodium tablets is not recommended.
Mechanism: Cholestyramine can slow down the absorption of naproxen into your system.
What to do: It is not recommended to take these two medications at the same time.
7 DRUG INTERACTIONS Lithium: Risk of lithium toxicity ( 7.2 ) Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Reduced diuretic, natriuretic and antihypotensive effects; increased risk of renal toxicity ( 7.3 ) Dual inhibition of the renin-angiotensin system: Increased risk of renal impairment, hypotension, and hyperkalemia ( 7.4 ) Colesevelam hydrochloride: Consider administering olmesartan at least 4 hours before colesevelam hydrochloride dose ( 7.5 ) Antidiabetic drugs: Dosage adjustment may be required ( 7.6 ) Cholestyramine and colestipol: Reduced absorption of thiazides ( 7.6 ) 7.1...
Mechanism: Cholestyramine can trap other medicines in your gut, which prevents your body from absorbing them properly. This can make your blood pressure medicine less effective.
What to do: You should talk to your doctor about how to time your doses. They may suggest taking your blood pressure medicine at least 4 hours before the cholestyramine.
7 DRUG INTERACTIONS Cholestyramine : Use with raloxifene hydrochloride is not recommended. (7.3 , 12.3) 7.1 Cholestyramine Concomitant administration of cholestyramine with raloxifene hydrochloride is not recommended.
Mechanism: Cholestyramine can stick to other medicines in your digestive tract and prevent them from being absorbed into your body. This makes the other medicine, like raloxifene, much less effective.
What to do: You should not take these two medications together. Ask your doctor if there is a different treatment option or a specific way to time your doses.
Drug Interactions Cholestyramine resin may delay or reduce the absorption of concomitant oral medication such as phenylbutazone, warfarin, thiazide diuretics (acidic) or propranolol (basic), as well as tetracycline, penicillin G, phenobarbital, thyroid and thyroxine preparations, estrogens and progestins and digitalis.
Mechanism: Cholestyramine can bind to propranolol in your gut and prevent it from entering your bloodstream. This means you might not get the full effect of the propranolol.
What to do: Take your other medications at least one hour before or four to six hours after taking cholestyramine.
Drug Interactions Cholestyramine resin may delay or reduce the absorption of concomitant oral medication such as phenylbutazone, warfarin, thiazide diuretics (acidic) or propranolol (basic), as well as tetracycline, penicillin G, phenobarbital, thyroid and thyroxine preparations, estrogens and progestins and digitalis.
Mechanism: Cholestyramine can trap warfarin in your digestive system, which stops your body from absorbing it. This can make the blood thinner less effective.
What to do: Your doctor may need to check your blood clotting time more often and adjust your warfarin dose.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I take cholestyramine with other medications?
What should I do if I get constipated?
How long will it take to see results?
Can I mix cholestyramine with any liquid?
What is the maximum dose I can take?
Do I need to follow a special diet while taking this medicine?
What if I have trouble swallowing the mixture?
Can cholestyramine cause vitamin deficiencies?
Will this medicine cure my high cholesterol?
What should I do if I experience side effects?
What are the common side effects of cholestyramine?
Does cholestyramine interact with other medications?
What drug class is cholestyramine?
Is cholestyramine safe during pregnancy?
Is cholestyramine currently in shortage?
Related Medications in Bile Acid Sequestrant
Other drugs grouped near cholestyramine - same-class peers and common alternatives.
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Praluent
Praluent is a medicine that can lower cholesterol.
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atorvastatin
Lipitor
Atorvastatin is a drug that lowers cholesterol and reduces the risk of heart problems and stroke.
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bempedoic acid
Nexletol
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bempedoic acid/ezetimibe
Nexlizet
Nexlizet is a combination medicine that helps lower cholesterol.
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colestipol
Colestid
Colestipol is a drug that helps lower cholesterol levels in your blood.
Compare with cholestyramine →
Medication Guides
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Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for cholestyramine
The FDA label for cholestyramine (sold under brand names such as Questran) classifies it as a prescription-only medication in the Bile Acid Sequestrant class. This medicine is used with a diet to lower high cholesterol, especially LDL cholesterol (the "bad" cholesterol). Official labeling lists 1 commonly reported side effect, including Constipation.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 11,539 voluntary reports. The database also lists 34 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.85.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: December 15, 2021
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages