colesevelam
Brand names: Welchol
Colesevelam is a medicine that helps lower bad cholesterol (LDL-C) and control blood sugar in adults. It can also lower LDL-C in children ages 10-17 with certain cholesterol problems.
Drug Pricing (NADAC)
Brand Price
$4.72/unit
Generic Price
$0.22/unit
Generic Savings
95%
Generic Available
Yes (11 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine can help lower high LDL cholesterol in adults and children (10-17 years old) who have primary hyperlipidemia or heterozygous familial hypercholesterolemia.
Common side effects
Constipation, Upset stomach, Nausea
Key warnings
Colesevelam can raise your triglyceride levels, which could cause pancreatitis.
How It Works
Colesevelam is a bile acid sequestrant. It works by binding to bile acids in your gut. This helps your body get rid of cholesterol and can also lower blood sugar levels.
How to Take It
The usual dose is 3.75 grams per day. You can take six tablets once a day, or three tablets twice a day with a meal and liquid. If you take the oral suspension, mix one packet with 1 cup of water, juice, or diet soda and drink it with a meal.
Pregnancy & Breastfeeding
This medicine is not absorbed into your body, so it is not expected to harm your baby during pregnancy. Talk to your doctor if you are pregnant or plan to become pregnant. This medicine is also not expected to pass into breast milk.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store this medicine at room temperature, away from moisture and heat.
Side Effects (from patient reports)
Based on 670 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 952 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2006–2025.
Total Reports
952
Death-Related Reports
32
Hospitalization Reports
277
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DIARRHOEA | 121 |
| 2 | DYSPNOEA | 72 |
| 3 | OFF LABEL USE | 66 |
| 4 | COUGH | 64 |
| 5 | DRUG INEFFECTIVE | 63 |
| 6 | MUSCLE SPASMS | 61 |
| 7 | FATIGUE | 59 |
| 8 | NAUSEA | 59 |
| 9 | NASOPHARYNGITIS | 56 |
| 10 | CARDIAC DISORDER | 49 |
| 11 | ABDOMINAL PAIN | 48 |
| 12 | ATRIAL FIBRILLATION | 48 |
| 13 | CHEST DISCOMFORT | 48 |
| 14 | DYSPNOEA EXERTIONAL | 46 |
| 15 | DYSPHONIA | 45 |
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
Colesevelam can raise your triglyceride levels, which could cause pancreatitis. Tell your doctor right away if you have severe stomach pain. This medicine may also cause bowel obstruction, especially if you have stomach problems or have had major surgery on your stomach or intestines. Colesevelam can also lower the amount of fat-soluble vitamins your body absorbs.
Known Drug Interactions
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 Age...
Mechanism: Colesevelam can stick to olmesartan in your stomach, which prevents your body from absorbing the blood pressure medicine correctly.
What to do: You should take your olmesartan dose at least 4 hours before you take colesevelam.
Concomitant use with colesevelam hydrochloride may increase the exposure of the following drugs: Metformin extended release. 7.2 Colesevelam Hydrochloride Drug Interactions that Increase the Exposure of the Concomitant Medication Table 5 Colesevelam Hydrochloride Drug Interactions that Increase the Exposure of the Concomitant Medication Metformin Extended Release (ER) Clinical Impact: In vivo drug interactions studies showed an increase in metformin extended release (ER) when coadministered with colesevelam hydrochloride [see Clinical Pharmacology (12.3) ].
Mechanism: Colesevelam can raise the levels of metformin in your body by increasing how much of the drug you are exposed to.
What to do: Your doctor may need to monitor your blood sugar more often or adjust your metformin dosage.
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). For patients on warfarin, monitor International Normalized Ratio (INR) frequently during initiation then periodically ( 7.1 ). Warfarin Clinical Impact: There have been postmarketing reports of reduced INR in patients...
Mechanism: Colesevelam can lower the amount of warfarin that gets into your blood by binding to the medicine in your stomach. This prevents the warfarin from being absorbed properly into your system.
What to do: Your doctor should check your blood clotting levels (INR) frequently when you start or stop this medication. They may need to adjust your warfarin dose.
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). Oral Contraceptives Containing Ethinyl Estradiol and Norethindrone Clinical Impact: In vivo drug interactions studies showed a decrease in exposure of ethinyl estradiol and norethindrone when coadministered with coles...
Mechanism: Colesevelam can reduce the amount of birth control medicine that enters your body. This happens because the drug can trap the birth control in your digestive system before it can work.
What to do: Talk to your doctor about the best timing for taking these medications to ensure your birth control stays effective. You may need to take them several hours apart.
7 DRUG INTERACTIONS Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). In vivo drug interactions studies showed a decrease in exposure of cyclosporine when coadministered with colesevelam hydrochloride [see Clinical Pharmacology (12.3) ]. Examples: Cyclosporine Phenytoin Clinical Impact:...
Mechanism: Colesevelam can lower the levels of cyclosporine in your body by blocking its absorption. This means there might not be enough medicine in your blood to work correctly.
What to do: Your doctor should monitor your blood levels of cyclosporine closely. They may need to adjust your dose or change when you take the medicine.
Common Questions
Can I take this with other medications?
What if I have trouble swallowing the tablets?
Can this medicine cause weight gain?
Will this medicine cure my diabetes or high cholesterol?
How long will it take to see results?
Are there any foods I should avoid while taking this medicine?
Can I drink alcohol while taking this medicine?
What should I do if I experience side effects?
Is there a generic version of this medicine?
Can children take this medicine?
What are the common side effects of colesevelam?
Does colesevelam interact with other medications?
What drug class is colesevelam?
Is there a generic version of colesevelam?
Is colesevelam safe during pregnancy?
Related Medications in Bile Acid Sequestrant (Diabetes)
Other drugs grouped near colesevelam — same-class peers and common alternatives.
acarbose
Precose
Acarbose is a medicine that helps lower blood sugar levels in people with type 2 diabetes.
Compare with colesevelam →
alogliptin
Nesina
Alogliptin and Metformin HCl is a drug that helps lower blood sugar in adults with type 2 diabetes.
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bromocriptine
Cycloset
Bromocriptine (Cycloset) is a medicine that acts like dopamine in your body.
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canagliflozin
Invokana
Invokana is a medicine used with diet and exercise to lower blood sugar in adults with type 2 diabetes.
Compare with colesevelam →
dapagliflozin
Farxiga
Dapagliflozin (Farxiga) helps lower blood sugar in adults with type 2 diabetes.
Compare with colesevelam →
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What the FDA Data Shows for colesevelam
The FDA label for colesevelam (sold under brand names such as Welchol) classifies it as a prescription-only medication in the Bile Acid Sequestrant (Diabetes) class. This medicine can help lower high LDL cholesterol in adults and children (10-17 years old) who have primary hyperlipidemia or heterozygous familial hypercholesterolemia. Official labeling lists 14 commonly reported side effects, including Constipation, Upset stomach, Nausea.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 670 voluntary reports. The database also lists 15 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 $0.22 versus $4.72 for the brand — a 95% generic savings.
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).
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 28, 2023
Read our methodology — how this data is sourced, computed, and verified.
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