Colesevelam Side Effects

Medically reviewed by Drugs.com. Last updated on May 29, 2025.

Applies to colesevelam: oral powder for suspension, oral tablet.

Precautions

It is very important that the doctor check your or your child's progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.

This medicine may increase triglyceride levels in the blood which may cause serious heart problems. Your doctor may check your triglycerides or fatty acids in the blood before using this medicine.

Your doctor may want to measure the cholesterol levels in your blood on a regular basis to make sure this medicine is working properly. Be sure to keep all of your appointments. You will also need to check your blood sugar regularly at home.

Do not stop using this medicine without first checking with your doctor. When you stop using this medicine, your blood cholesterol and sugar levels may increase again.

This medicine can cause low blood sugar (hypoglycemia). The symptoms of low blood sugar must be treated before they lead to unconsciousness (passing out). People may feel different symptoms with a low blood sugar. It is important that you learn which symptoms you get when your blood sugar is low. The symptoms of low blood sugar include: anxiety, behavior change similar to being drunk, blurred vision, cold sweats, confusion, cool, pale skin, difficulty with thinking, drowsiness, excessive hunger, a fast heartbeat, continuing headache, nausea, nervousness, nightmares, restless sleep, shakiness, slurred speech, and unusual tiredness or weakness.

If you have any symptoms of low blood sugar, check your blood sugar level right away. If needed, you can eat glucose tablets or gel, corn syrup, honey, or sugar cubes, or you can drink fruit juice, a non-diet soft drink, or sugar dissolved in water.

Check with your doctor right away if you have sudden and severe stomach pain, chills, constipation, nausea, vomiting, fever, or lightheadedness. These may be symptoms of acute pancreatitis.

This medicine can cause constipation, and for some people this can be very uncomfortable. If you have problems with severe constipation while using this medicine, talk to your doctor.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of colesevelam

Along with its needed effects, colesevelam may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking colesevelam:

Other side effects of colesevelam

Some side effects of colesevelam may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to colesevelam: oral powder for reconstitution, oral tablet.

General adverse events

The most frequently reported side effects were constipation, dyspepsia, and nausea.^[Ref]

Gastrointestinal

• Very common (10% or more): Constipation (up to 11%), flatulence
• Common (1% to 10%): Dyspepsia, nausea, vomiting, diarrhea, abdominal pain, abnormal stools, abdominal distension
• Uncommon (0.1% to 1%): Dysphagia
• Very rare (less than 0.01%): Pancreatitis
• Frequency not reported: Intestinal obstruction
• Postmarketing reports: Bowel obstruction, esophageal obstruction, fecal impaction, exacerbation of hemorrhoids, pancreatitis^[Ref]

Metabolic

• Common (1% to 10%): Hypertriglyceridemia, hypoglycemia^[Ref]

Cardiovascular

• Common (1% to 10%): Hypertension, myocardial infarction, aortic stenosis, bradycardia^[Ref]

Respiratory

• Common (1% to 10%): Pharyngitis, rhinitis, nasopharyngitis, upper respiratory tract infection^[Ref]

Other

• Common (1% to 10%): Accidental injury, asthenia, flu syndrome/influenza, fatigue, creatine phosphokinase increased
• Uncommon (0.1% to 1%): Serum transaminases increased^[Ref]

Musculoskeletal

• Common (1% to 10%): Myalgia, back pain^[Ref]

Nervous system

• Common (1% to 10%): Headache
• Postmarketing reports: Increased seizure activity (resulting from decreased phenytoin levels)^[Ref]

Hypersensitivity

• Frequency not reported: Hypersensitivity reaction^[Ref]

In clinical trials of type 2 diabetes, patient who received this drug as an add on to a sulfonylurea discontinued the trial due to body rash and mouth blistering that occurred on the first day of therapy.^[Ref]

Hematologic

• Postmarketing reports: Reduced international normalized ration (INR) in patient on warfarin therapy

Hepatic

• Postmarketing reports: Increased transaminases

Endocrine

• Postmarketing reports: Elevated thyroid-stimulating hormone (TSH) in patients receiving thyroid hormone replacement

See also:

Further information

Colesevelam side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer