Linzess Dosing Recommendations
For adults with IBS-C, use linaclotide 290 mcg once daily; for adults with CIC, use 145 mcg once daily (or 72 mcg once daily if tolerability is a concern). 1
Dosing by Indication
IBS-C (Irritable Bowel Syndrome with Constipation)
- 290 mcg orally once daily is the FDA-approved and guideline-recommended dose for all adult patients with IBS-C 1
- This dose has been extensively validated in multiple Phase 3 trials, achieving FDA composite endpoint responder rates of 33.6-33.7% versus 13.9-21.0% for placebo 2, 3, 4
- The 290 mcg dose significantly improves both abdominal pain (48.9% responder rate vs. 34.5% placebo) and bowel movements (47.6% CSBM responder rate vs. 22.6% placebo) 4
CIC (Chronic Idiopathic Constipation)
- 145 mcg orally once daily is the standard recommended dose 1
- 72 mcg orally once daily may be used as an alternative based on individual presentation or tolerability concerns 1
- Both doses significantly increase complete spontaneous bowel movements (CSBMs by 1.37 per week), spontaneous bowel movements (SBMs by 1.97 per week), and improve stool consistency (Bristol Stool Scale improvement of 1.25) compared to placebo 3
Critical Administration Instructions
Timing and Method
- Take on an empty stomach at least 30 minutes before the first meal of the day, at approximately the same time each day 5, 1
- Taking with food significantly reduces efficacy 5
- If a dose is missed, skip it and take the next dose at the regular time—never take 2 doses at the same time 5, 1
Capsule Administration
- Swallow capsules whole; do not crush or chew the capsule or its contents 1
- For patients unable to swallow capsules whole, the capsule may be opened and administered with applesauce or water, or via nasogastric/gastrostomy tube following specific instructions 1
Safety Profile and Common Pitfalls
Diarrhea Management
- Diarrhea is the most common adverse effect, occurring in approximately 16-20% of patients (vs. 2-3% with placebo) 6, 7, 4
- Most diarrhea is mild to moderate (90.5% of cases) 6
- Diarrhea leads to treatment discontinuation in approximately 4-4.5% of patients 3, 6, 4
- If diarrhea is problematic in CIC patients, consider dose reduction from 145 mcg to 72 mcg 3, 1
Contraindications
- Absolutely contraindicated in patients with known or suspected mechanical gastrointestinal obstruction 3, 5, 1
- Contraindicated in patients less than 2 years of age due to risk of serious dehydration 1
Predictors of Response
- Clinical response at week 4 strongly predicts sustained response at week 12 (OR: 6.5; 95% CI: 2.1-19.8) 8
- Consider reassessing treatment continuation if no response is observed by week 4 8
Treatment Duration
- Clinical trials evaluated treatment for 12-26 weeks, with long-term safety data available for up to 104 weeks 6, 4
- The FDA label does not provide a limit on treatment duration 3
- In real-world practice, the most common reasons for discontinuation over the first year are loss of efficacy and insurance coverage barriers rather than adverse events 3