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Welchol Side Effects

Generic Name: colesevelam

Note: This page contains side effects data for the generic drug colesevelam. It is possible that some of the dosage forms included below may not apply to the brand name Welchol.

In Summary

Common side effects of Welchol 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

As well as its needed effects, colesevelam (the active ingredient contained in Welchol) may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking colesevelam, check with your doctor immediately:

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

Minor Side Effects

Some colesevelam side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

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


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


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[Ref]


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


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


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


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


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

Nervous system

Common (1% to 10%): Headache[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]

Frequency not reported: Hypersensitivity reaction[Ref]


1. "Product Information. Welchol (colesevelam)" Daiichi Sankyo, Inc., Parsippany, NJ.

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

It is possible that some side effects of Welchol may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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