Welchol (Colesevelam) Dosing for Diarrhea
Welchol (colesevelam) is typically dosed at 1875 mg (3 tablets of 625 mg each) twice daily for diarrhea, meaning you take it 2 times per day. 1, 2
Standard Dosing Regimen
- Take 3 tablets (625 mg each = 1875 mg) twice daily with meals for bile acid diarrhea 1, 2
- This translates to morning and evening dosing, for a total daily dose of 3750 mg 1, 2
- Some protocols start with 2 tablets (1250 mg) twice daily and titrate up based on response 1, 2
Titration and Response Timeline
- Initial titration occurs over the first 5 days of treatment, adjusting the dose to achieve optimal effect 1
- Clinical response typically occurs within the first 2 weeks of starting colesevelam, so you should see improvement quickly if it's going to work 2
- The medication can be continued long-term if effective, with sustained benefit demonstrated over 6 months 3
Clinical Context and Effectiveness
The evidence strongly supports colesevelam for bile acid diarrhea:
- In randomized controlled trials, 59-64% of patients achieved complete remission of diarrhea symptoms with colesevelam versus only 13-16% with placebo 1
- 88% of patients with lenalidomide-associated diarrhea responded to colesevelam, with 68% achieving complete resolution 2
- The mechanism works by sequestering bile acids in the intestinal lumen, which reduces their diarrhea-inducing effects 4, 5
Important Caveats
- Colesevelam does not interfere with absorption of other medications like lenalidomide, based on pharmacokinetic studies 2
- Mild gastrointestinal side effects (constipation, bloating, abdominal pain) can occur but are generally transient and well-tolerated 1, 2
- No serious adverse events have been reported in clinical trials of colesevelam for diarrhea 1
- Take with meals to optimize bile acid binding when bile acids are released into the intestine 1, 2
When Colesevelam May Not Be Appropriate
Note that the provided guidelines focus on cancer treatment-induced diarrhea and recommend loperamide as first-line therapy, not bile acid sequestrants 6. Colesevelam is specifically indicated for bile acid diarrhea, not all types of diarrhea. If your diarrhea is from chemotherapy, radiation, or other causes unrelated to bile acid malabsorption, loperamide (starting at 4 mg, then 2 mg every 4 hours, maximum 16 mg daily) would be the preferred initial treatment 6, 7.