Cholestagel (Colesevelam)
Bile acid sequestrant for lowering cholesterol in adults with primary hypercholesterolaemia
Cholestagel (colesevelam hydrochloride) is a bile acid sequestrant used to lower LDL cholesterol in adults with primary hypercholesterolaemia. It works by binding bile acids in the intestine, preventing their reabsorption and forcing the liver to use blood cholesterol to produce new bile acids. Cholestagel is available as 625 mg film-coated tablets and can be used alone or in combination with statins and/or ezetimibe, alongside a cholesterol-lowering diet.
Quick Facts
Key Takeaways
- Cholestagel lowers LDL cholesterol by binding bile acids in the intestine, which is a completely different mechanism from statins
- Tablets must be swallowed whole with food and plenty of liquid – never crush, break, or chew them
- The most common side effects are flatulence and constipation; these usually improve over time
- Cholestagel may affect absorption of other medications – take other drugs at least 4 hours before or after
- Not suitable for patients with bowel or biliary obstruction, or those with very high triglyceride levels
What Is Cholestagel and What Is It Used For?
Quick Answer: Cholestagel contains the active substance colesevelam hydrochloride. It is a prescription medicine that helps lower LDL (bad) cholesterol levels in adults with primary hypercholesterolaemia, when diet alone is insufficient.
Cholestagel belongs to a class of medications called bile acid sequestrants (also known as bile acid-binding resins). These drugs work within the gastrointestinal tract rather than being absorbed into the bloodstream, making them a unique option for cholesterol management. Your doctor should prescribe Cholestagel only after confirming that a low-fat, low-cholesterol diet has not been sufficient to achieve desired cholesterol levels.
The mechanism of action is elegant in its simplicity. Bile acids are produced by the liver from cholesterol and secreted into the intestine to help digest dietary fats. Normally, about 95% of these bile acids are reabsorbed from the intestine and recycled back to the liver – a process known as enterohepatic circulation. Cholestagel works by binding to bile acids in the intestinal tract and forming an insoluble complex that is excreted from the body through the faeces. By interrupting this recycling process, the liver is forced to draw on blood cholesterol to synthesise replacement bile acids, which results in a measurable reduction in circulating LDL cholesterol.
Clinical trials have demonstrated that colesevelam can reduce LDL cholesterol by approximately 15–18% when used alone, and when combined with a statin, the additional LDL reduction may reach 10–16% beyond the statin’s effect. According to the European Society of Cardiology and European Atherosclerosis Society (ESC/EAS) guidelines on dyslipidaemia management, bile acid sequestrants are recognised as a second-line option for patients who need additional LDL-C lowering or who cannot tolerate statins.
Cholestagel is prescribed in three main clinical scenarios:
- Monotherapy – used alone alongside a low-fat, low-cholesterol diet, when statin therapy is considered inappropriate or is not tolerated
- Combination with a statin – added to ongoing statin therapy when the statin alone does not provide sufficient cholesterol lowering
- Combination with ezetimibe – used with ezetimibe (a cholesterol absorption inhibitor), with or without a statin, for additional LDL-C reduction
It is important to note that Cholestagel is approved only for use in adults (aged 18 years and older). The safety and efficacy of colesevelam in children and adolescents have not been established, and the medication is therefore not recommended for use in patients under 18 years of age.
Cholestagel is not absorbed into the bloodstream – it works entirely within the intestine. This local action means it has fewer systemic side effects compared with some other cholesterol-lowering medications, but it can still affect absorption of other drugs and fat-soluble vitamins.
What Should You Know Before Taking Cholestagel?
Quick Answer: Do not take Cholestagel if you are allergic to colesevelam or have bowel or biliary obstruction. Tell your doctor if you have high triglycerides, swallowing difficulties, or severe gastrointestinal conditions before starting this medicine.
Contraindications
There are specific situations in which Cholestagel must not be used. You should not take Cholestagel if:
- You are allergic (hypersensitive) to colesevelam hydrochloride or any of the other ingredients in the tablet (listed in the composition section below)
- You have a bowel obstruction (intestinal blockage) – since Cholestagel acts in the gut, any obstruction could lead to serious complications
- You have a biliary obstruction (blockage of the bile ducts) – if bile cannot flow normally, binding bile acids in the intestine would be ineffective and potentially harmful
If Cholestagel is prescribed alongside other cholesterol-lowering medications (such as a statin or ezetimibe), you should also carefully read the patient information leaflet for those additional medicines and observe their individual contraindications.
Warnings and Precautions
Before starting treatment with Cholestagel, it is essential to discuss the following conditions with your healthcare provider:
- Elevated triglycerides: If your blood triglyceride levels are above 3.4 mmol/L (approximately 300 mg/dL), Cholestagel should be used with caution. Bile acid sequestrants are known to potentially increase triglyceride levels, and patients with baseline hypertriglyceridaemia (above 5.0 mmol/L) should generally not use this medication. Your doctor should monitor your triglyceride levels during treatment.
- Swallowing difficulties (dysphagia): The Cholestagel tablets are relatively large and must be swallowed whole. If you have any condition that makes swallowing difficult, inform your doctor, as there is a risk of oesophageal obstruction.
- Gastrointestinal conditions: If you suffer from chronic constipation, gastroparesis, or other serious gastrointestinal disorders, Cholestagel may worsen these conditions. This is especially relevant for patients with coronary artery disease and angina, in whom severe constipation could trigger cardiovascular events.
- Fat-soluble vitamin deficiency: Because Cholestagel may reduce the absorption of fat-soluble vitamins (A, D, E, and K), your doctor may wish to monitor your vitamin levels periodically. Supplementation may be recommended if deficiency is detected.
Before initiating therapy, your doctor should also rule out secondary causes of hypercholesterolaemia, including:
- Poorly controlled diabetes mellitus
- Untreated hypothyroidism (low thyroid hormone levels)
- Nephrotic syndrome (protein in the urine)
- Dysproteinaemia (abnormal protein levels in the blood)
- Obstructive liver disease
Treating these underlying conditions may improve cholesterol levels without the need for additional medications.
Pregnancy and Breastfeeding
If you are pregnant, breastfeeding, suspect you may be pregnant, or are planning to become pregnant, consult your doctor or pharmacist before using Cholestagel. Although colesevelam is not absorbed systemically, it may impair the absorption of fat-soluble vitamins that are essential for foetal development.
Critically, if Cholestagel is prescribed in combination with a statin, the statin must not be used during pregnancy as statins can cause serious harm to the developing foetus. Inform your doctor immediately if you become pregnant while taking a statin-Cholestagel combination.
If you are breastfeeding, discuss this with your prescribing physician. Your doctor may recommend discontinuing treatment during this period, as the effects of reduced vitamin absorption on breast milk composition have not been fully studied.
Driving and Using Machines
Cholestagel is not expected to affect your ability to drive or operate machinery. It does not cause drowsiness, dizziness, or any other central nervous system effects that would impair your ability to perform these activities safely.
How Does Cholestagel Interact with Other Drugs?
Quick Answer: Cholestagel can affect the absorption of many other medications. As a general rule, take other medicines at least 4 hours before or 4 hours after Cholestagel. Always inform your doctor about all medications you are currently taking.
Because Cholestagel works by binding substances in the intestine, it can interfere with the absorption of other orally administered medications. This is a class effect shared by all bile acid sequestrants. Your doctor may advise you to take Cholestagel at least 4 hours before or 4 hours after any other medication to minimise the risk of reduced absorption.
Even though Cholestagel itself is taken once or twice daily, the other medication may need to be dosed multiple times throughout the day. In these cases, only the Cholestagel dose needs to be separated – you do not need to change the timing of each individual dose of the other medicine.
Major Interactions
| Medication | Type | Clinical Significance | Recommendation |
|---|---|---|---|
| Warfarin | Anticoagulant | Cholestagel may reduce absorption of vitamin K, altering warfarin’s anticoagulant activity and INR values | Close INR monitoring required; dose adjustment of warfarin may be necessary |
| Levothyroxine / Thyroxine | Thyroid hormone | May reduce absorption of thyroid hormones, leading to inadequate thyroid replacement | Take levothyroxine at least 4 hours before or after Cholestagel; monitor TSH levels |
| Oral contraceptives | Hormonal contraception | May reduce absorption of oestrogen and/or progestogen, potentially reducing contraceptive efficacy | Take oral contraceptive at least 4 hours before Cholestagel |
| Olmesartan | Antihypertensive (ARB) | Reduced bioavailability of olmesartan when co-administered | Take olmesartan at least 4 hours before Cholestagel |
| Ciclosporin | Immunosuppressant | May affect ciclosporin absorption; variable effects reported | Always take ciclosporin at consistent timing relative to Cholestagel; monitor ciclosporin levels |
| Phenytoin | Antiepileptic | Bile acid sequestrants may reduce phenytoin absorption | Monitor phenytoin levels; consider dose separation |
Additional Interactions
| Medication | Type | Recommendation |
|---|---|---|
| Glimepiride / Glipizide | Diabetes (sulfonylureas) | Take glimepiride or glipizide at least 4 hours before Cholestagel |
| Metformin ER | Diabetes (biguanide) | Monitor blood glucose closely; extended-release formulation may be affected |
| Pioglitazone / Repaglinide / Glyburide | Diabetes | Monitor diabetes treatment carefully |
| Verapamil | Calcium channel blocker | Separate dosing by at least 4 hours |
| Ursodeoxycholic acid | Gallstone dissolution / liver | Separate dosing; Cholestagel may bind ursodeoxycholic acid in the intestine |
Fat-Soluble Vitamins
Because Cholestagel can interfere with the absorption of fat-soluble vitamins (A, D, E, and K), your doctor may periodically check your vitamin levels during treatment. This is particularly important for patients who may be at risk of vitamin deficiency due to existing medical conditions, dietary restrictions, or prolonged treatment duration. Vitamin supplementation may be recommended if a deficiency is detected.
Keep a simple schedule card listing all your medications and the times you take them. This makes it easier to ensure proper dose separation from Cholestagel. Share this card with your doctor at each visit.
What Is the Correct Dosage of Cholestagel?
Quick Answer: The typical dose is 6 tablets daily (3.75 g), taken with meals. When used as monotherapy, take 3 tablets twice daily or 6 tablets once daily. In combination therapy, take 4–6 tablets daily. Always follow your doctor’s individual instructions.
Always take Cholestagel exactly as directed by your doctor or pharmacist. Before starting treatment, you should be advised to follow a cholesterol-lowering diet and continue this diet throughout the course of treatment. The tablets must be taken with food and liquid, and they should be swallowed whole – do not break, crush, or chew the tablets.
Adults
The dosage depends on whether Cholestagel is used alone or in combination with other cholesterol-lowering medications:
Monotherapy (Cholestagel alone)
The recommended dose is 3 tablets twice daily with meals, or 6 tablets once daily with a meal. Your doctor may increase the dose to a maximum of 7 tablets per day (4,375 mg) if needed for adequate cholesterol control.
Combination Therapy (with a statin and/or ezetimibe)
The recommended dose is 4 to 6 tablets per day, taken either once daily or divided into two doses, always with meals. The dose of the statin and/or ezetimibe should follow the prescribing instructions for those individual medications. These medicines can be taken at the same time or at different times, depending on your doctor’s advice.
| Regimen | Daily Dose | Tablets / Day | Frequency |
|---|---|---|---|
| Monotherapy | 3,750 mg | 6 tablets | Once or twice daily with meals |
| Monotherapy (max) | 4,375 mg | 7 tablets | As directed by doctor |
| Combination therapy | 2,500–3,750 mg | 4–6 tablets | Once or twice daily with meals |
Children and Adolescents
The safety and efficacy of Cholestagel have not been studied in children and adolescents (under 18 years of age). Cholestagel is therefore not recommended for this patient group. If a child or adolescent has high cholesterol, the prescribing physician should consider other treatment options that have been evaluated in paediatric populations.
Elderly Patients
No specific dose adjustment is required for elderly patients. However, as older adults may be more susceptible to constipation and gastrointestinal side effects, doctors should monitor these patients carefully. It is also important to ensure adequate hydration and fibre intake when taking Cholestagel, as this can help mitigate constipation.
Missed Dose
If you forget to take your Cholestagel dose, you may take it with a later meal on the same day. However, never take more tablets in a single day than the total number prescribed by your doctor. Do not take a double dose to make up for a missed one. Simply continue with your regular dosing schedule the next day.
Overdose
If you take more Cholestagel than prescribed, contact your doctor or pharmacist. Because colesevelam is not absorbed into the bloodstream, systemic toxicity is not expected. However, overdose may lead to exacerbation of the known gastrointestinal side effects, including constipation and abdominal bloating. Treatment is generally supportive and symptomatic.
Stopping Treatment
Do not stop taking Cholestagel without consulting your doctor. If you discontinue the medication, your cholesterol levels may return to the elevated levels seen before treatment was started. Your doctor will work with you to determine the appropriate duration of therapy based on your individual risk profile and treatment goals.
If you also take ciclosporin (or Neoral®), be consistent: always take ciclosporin at the same time relative to Cholestagel, whether together or separated. Inconsistent timing can lead to unpredictable ciclosporin levels.
What Are the Side Effects of Cholestagel?
Quick Answer: The most common side effects are flatulence and constipation (affecting more than 1 in 10 patients). Common effects also include nausea, abdominal pain, and headache. Serious but rare effects include pancreatitis and bowel obstruction.
Like all medicines, Cholestagel can cause side effects, although not everyone experiences them. The side effects are organised below by how frequently they occur, based on clinical trial data and post-marketing surveillance. Most gastrointestinal side effects tend to be mild to moderate and often improve as your body adjusts to the medication over the first few weeks of treatment.
Very Common
May affect more than 1 in 10 people
- Flatulence (gas/bloating)
- Constipation
Common
May affect up to 1 in 10 people
- Nausea
- Vomiting
- Diarrhoea
- Indigestion (dyspepsia)
- Abdominal pain
- Abnormal stools
- Abdominal distension (bloated stomach)
- Headache
- Increased blood triglyceride levels
Uncommon
May affect up to 1 in 100 people
- Muscle pain (myalgia)
- Elevated liver enzyme levels
- Difficulty swallowing (dysphagia)
Very Rare
May affect up to 1 in 10,000 people
- Pancreatitis (inflammation of the pancreas)
Frequency Not Known
Cannot be estimated from available data
- Bowel obstruction (more likely in patients with a history of bowel obstruction or previous bowel surgery)
The gastrointestinal side effects (constipation, flatulence, bloating) are a predictable consequence of Cholestagel’s mechanism of action. The non-absorbed bile acid complex increases the bulk and viscosity of intestinal contents, which can slow gastrointestinal transit. Adequate fluid intake (at least 1.5–2 litres of water daily) and a fibre-rich diet can help minimise these effects.
The potential for increased triglyceride levels is an important consideration. Bile acid sequestrants can stimulate hepatic very low-density lipoprotein (VLDL) production, which carries triglycerides. Your doctor should monitor your lipid panel, including triglycerides, periodically throughout treatment – particularly during the first few months.
Contact your doctor or seek emergency medical care immediately if you experience severe abdominal pain (which could indicate pancreatitis or bowel obstruction), persistent vomiting, or complete inability to pass stool or gas. These symptoms require urgent medical evaluation.
If you experience any side effects, including those not listed above, talk to your doctor or pharmacist. Reporting suspected side effects helps regulatory authorities continuously monitor the benefit-risk balance of medicines. In the EU, you can report side effects through your national reporting system. In the US, side effects can be reported to the FDA’s MedWatch programme.
How Should You Store Cholestagel?
Quick Answer: Store Cholestagel in the original container, tightly closed, away from moisture. Keep out of sight and reach of children and do not use after the expiry date.
Proper storage of medications is essential to maintain their effectiveness and safety. Follow these guidelines for storing Cholestagel:
- Keep out of the sight and reach of children – store in a location inaccessible to young children
- Do not use after the expiry date – the expiry date is printed on the carton and bottle label after “EXP”. The expiry date refers to the last day of that month
- Keep the bottle tightly closed – Cholestagel tablets are sensitive to moisture; always replace the cap securely after use
- No special temperature requirements – store at room temperature; avoid excessive heat and humidity (do not store in the bathroom)
Do not dispose of medicines in wastewater or household rubbish. Ask your pharmacist about the proper way to dispose of medicines no longer in use. These measures help to protect the environment.
What Does Cholestagel Contain?
Quick Answer: Each Cholestagel tablet contains 625 mg of the active substance colesevelam (as hydrochloride). The off-white, oval, film-coated tablets are marked “C625” on one side.
The active substance is colesevelam hydrochloride. Each film-coated tablet contains 625 mg colesevelam. Colesevelam is a non-absorbed, cross-linked polymer that acts as a bile acid-binding agent. Its high molecular weight and insolubility prevent it from being absorbed across the intestinal wall and into the systemic circulation.
The inactive ingredients (excipients) include:
Tablet Core
- Microcrystalline cellulose (E460)
- Colloidal anhydrous silica
- Magnesium stearate
- Purified water
Film Coating
- Hypromellose (E464)
- Diacetylated monoglycerides
Printing Ink
- Black iron oxide (E172)
- Hypromellose (E464)
- Propylene glycol
Appearance and Pack Sizes
Cholestagel tablets are off-white, oval, film-coated tablets imprinted with “C625” on one side. The tablets are packaged in plastic bottles with child-resistant closures. Available pack sizes are:
- 24 tablets (1 × 24)
- 100 tablets (2 × 50)
- 180 tablets (1 × 180)
Not all pack sizes may be marketed in every country.
The marketing authorisation holder is CHEPLAPHARM Arzneimittel GmbH (Greifswald, Germany), and the manufacturer is Genzyme Ireland Ltd. (Waterford, Ireland).
Frequently Asked Questions About Cholestagel
Cholestagel (colesevelam) is used to treat primary hypercholesterolaemia (high cholesterol) in adults. It works by binding bile acids in the intestine, which forces the liver to use cholesterol from the blood to produce new bile acids, thereby lowering LDL (“bad”) cholesterol levels. It can be used alone when statins are not suitable, or in combination with statins and/or ezetimibe for additional cholesterol-lowering effect.
Take Cholestagel tablets with food and plenty of liquid. The tablets must be swallowed whole – never break, crush, or chew them. When used alone, the usual dose is 3 tablets twice daily or 6 tablets once daily with meals. In combination therapy, 4–6 tablets daily is the typical dose. Always follow your doctor’s specific instructions regarding dose and timing.
The most common side effects are gastrointestinal in nature: flatulence (gas) and constipation are very common, affecting more than 1 in 10 people. Other common side effects include nausea, vomiting, diarrhoea, abdominal pain, indigestion, headache, and increased triglyceride levels. Most of these effects tend to improve over time. Drinking plenty of water and eating a fibre-rich diet can help reduce constipation.
Yes, but with care. Cholestagel can affect the absorption of many other medications, including warfarin, levothyroxine, oral contraceptives, and some diabetes medications. As a general rule, take other medicines at least 4 hours before or 4 hours after Cholestagel. Always tell your doctor about all medications, supplements, and herbal products you take so that appropriate dose timing can be arranged.
Cholestagel and statins lower cholesterol through completely different mechanisms. Statins reduce cholesterol production in the liver by blocking the enzyme HMG-CoA reductase, while Cholestagel binds bile acids in the intestine to prevent their reabsorption. Because they work differently, they can be combined for greater effect. Cholestagel is not absorbed into the bloodstream, which gives it a different side-effect profile – mainly gastrointestinal effects rather than the muscle-related effects sometimes seen with statins.
Cholestagel itself is not absorbed into the bloodstream, but it may reduce the absorption of fat-soluble vitamins (A, D, E, K) that are important during pregnancy. If you are pregnant or planning to become pregnant, discuss this with your doctor. Critically, if you are taking Cholestagel in combination with a statin, the statin must be stopped immediately as statins are contraindicated in pregnancy and can cause harm to the developing foetus.
References
This article is based on the following peer-reviewed sources, international guidelines, and regulatory documents:
- European Medicines Agency (EMA). “Cholestagel – Summary of Product Characteristics (SmPC).” EMA, last updated 2024. Available at: ema.europa.eu
- Mach F, Baigent C, Catapano AL, et al. “2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk.” European Heart Journal. 2020;41(1):111–188. doi:10.1093/eurheartj/ehz455
- National Institute for Health and Care Excellence (NICE). “Cardiovascular disease: risk assessment and reduction, including lipid modification.” Clinical guideline CG181, updated 2023. nice.org.uk
- Grundy SM, Stone NJ, Bailey AL, et al. “2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol.” Journal of the American College of Cardiology. 2019;73(24):e285–e350. doi:10.1016/j.jacc.2018.11.003
- Rosenson RS. “Bile acid sequestrants for the treatment of hypercholesterolemia.” UpToDate. Reviewed 2025. uptodate.com
- World Health Organization (WHO). “WHO Model List of Essential Medicines – 23rd List.” WHO, 2023.
- British National Formulary (BNF). “Colesevelam hydrochloride.” BNF, accessed January 2026. bnf.nice.org.uk
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