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Colesevelam Side Effects

In Summary

Commonly reported side effects of colesevelam include: constipation. Other side effects include: dyspepsia. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to colesevelam: oral powder for suspension, oral tablet

In addition to its needed effects, some unwanted effects may be caused by colesevelam. In the event that any of these side effects do occur, they may require medical attention.

Severity: Major

You should check with your doctor immediately if any of these side effects occur when taking colesevelam:

Less common:
  • Anxiety
  • blurred vision
  • chills
  • cold sweats
  • coma
  • confusion
  • congestion
  • cool, pale skin
  • cough
  • depression
  • diarrhea
  • dizziness
  • dry or sore throat
  • fast heartbeat
  • fever
  • general feeling of discomfort or illness
  • headache
  • hoarseness
  • increased hunger
  • joint pain
  • loss of appetite
  • muscle aches or pain
  • nausea
  • nervousness
  • nightmares
  • pounding in the ears
  • runny nose
  • seizures
  • shakiness
  • shivering
  • slow or fast heartbeat
  • slurred speech
  • sweating
  • tender, swollen glands in the neck
  • trouble with sleeping
  • trouble with swallowing
  • unusual tiredness or weakness
  • voice changes
  • vomiting
Incidence not known:
  • Bleeding after defecation
  • darkened urine
  • difficulty with swallowing
  • indigestion
  • pain or discomfort in the chest
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • pressure in the stomach
  • severe stomach pain
  • swelling of the abdominal or stomach area
  • unable to swallow saliva
  • uncomfortable swelling around the anus
  • yellow eyes or skin

Severity: Minor

Some of the side effects that can occur with colesevelam may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Acid or sour stomach
  • belching
  • bloating
  • constipation
  • full or bloated feeling
  • heartburn
  • pain or cramping in the abdomen or stomach
  • stomach discomfort, upset, or pain
Less common:
  • Lack or loss of strength
  • sneezing
  • stuffy nose

For Healthcare Professionals

Applies to colesevelam: oral powder for reconstitution, oral tablet


Cardiovascular side effects including hypertension, myocardial infarction, aortic stenosis, and bradycardia have been reported in 3% of patients.


Gastrointestinal side effects have included flatulence (12%), constipation (8.7% to 11%), dyspepsia (3.9% to 8%), diarrhea (5%), and nausea (3% to 4%). Bowel obstruction (in patients with a history of bowel obstruction or resection), dysphagia or esophageal obstruction (occasionally requiring medical intervention), fecal impaction, pancreatitis, abdominal distension, exacerbation of hemorrhoids, and increased transaminases have been reported in postmarketing experience.[Ref]


Immunologic side effects have included infection (10%).[Ref]


In the lipid-lowering trials, 807 patients received at least one dose of colesevelam therapy (total exposure 199 patient-years). In the type 2 diabetes trials, 566 patients received at least one dose of colesevelam therapy (total exposure 209 patient years). In clinical trials for the reduction of LDL-C, 68% of patients receiving colesevelam therapy versus 64% of patients receiving placebo reported an adverse event. In clinical trials of type 2 diabetes, 60% of patients receiving colesevelam therapy versus 56% of patients receiving placebo reported an adverse event.[Ref]


Respiratory side effects have included nasopharyngitis (4%), pharyngitis (3%), rhinitis (3%), sinusitis (2%), and increased cough (2%).[Ref]


Musculoskeletal side effects have included myalgia (2%).[Ref]


Metabolic side effects have included hypoglycemia (3%). Hypertriglyceridemia has been reported in postmarketing experience.[Ref]

Nervous system

Nervous system side effects have included headache (6%), pain (6%), and back pain (3%).


Other side effects have included abdominal pain (5%), accidental injury (4%), asthenia (4%), and flu syndrome (3%).


1. "Product Information. Welchol (colsevelam)" Southwood Pharmaceuticals Inc, Lake Forest, CA.

2. Davidson MH, Dillon MA, Gordon B, Jones P, Samuels J, Weiss S, Isaacsohn J, Toth P, Burke SK "Colesevelam hydrochloride (Cholestagel) - A new, potent bile acid sequestrant associated with a low incidence of gastrointestinal side effects." Arch Intern Med 159 (1999): 1893-900

Not all side effects for colesevelam may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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