Linzess Dosing and Administration
Recommended Dosing by Indication
For adults with IBS-C, the recommended dose is 290 mcg orally once daily, while for adults with CIC, the recommended dose is 145 mcg orally once daily (with 72 mcg once daily as an alternative based on individual presentation or tolerability). 1
Specific Dosing Regimens:
IBS-C (Irritable Bowel Syndrome with Constipation): 290 mcg once daily 1
CIC (Chronic Idiopathic Constipation): 145 mcg once daily as the standard dose 1
Pediatric patients (6-17 years) with Functional Constipation: 72 mcg once daily 1
Critical Administration Instructions
Linzess must be taken on an empty stomach at least 30 minutes before the first meal of the day, as taking it with food significantly reduces efficacy. 2, 3, 1
Key Administration Details:
Timing: Take at approximately the same time each day 1
Missed dose: Skip the missed dose and take the next dose at the regular time—never take 2 doses at the same time 3, 1
Capsule integrity: Do not crush or chew the capsule or capsule contents; swallow whole 1
Alternative Administration Methods:
For patients unable to swallow capsules whole 1:
With applesauce: Open capsule, sprinkle entire contents on one teaspoonful of room-temperature applesauce, consume immediately without chewing beads 1
With water: Open capsule, sprinkle contents into 30 mL room-temperature water, gently swirl for 20 seconds, swallow immediately 1
Via NG/G-tube: Mix beads with 30 mL water, draw into catheter-tipped syringe, dispense with rapid steady pressure (10 mL/10 seconds), flush tube with minimum 10 mL water 1
Clinical Context and Evidence
The 290 mcg dose for IBS-C is supported by high-quality evidence showing 33.6-33.7% responder rates versus 13.9-21.0% for placebo on the FDA composite endpoint (improvement of ≥30% in abdominal pain and increase of ≥1 CSBM from baseline for at least 6/12 weeks). 4, 5 The number needed to treat is approximately 5-8 patients. 4, 6
For CIC, the 145 mcg and 72 mcg doses demonstrate significant improvements in complete spontaneous bowel movements per week (increase of 1.37 compared to placebo) and spontaneous bowel movements per week (increase of 1.97 compared to placebo). 7
The 290 mcg dose approved for IBS-C can also be considered for CIC patients, recognizing that these conditions overlap and are often indistinguishable in clinical practice. 2
Safety Considerations and Common Pitfalls
Diarrhea is the most common adverse effect, occurring in 10-20% of patients, leading to discontinuation in approximately 4.5-5.7% of cases. 2, 7, 8, 4, 5
Critical Safety Points:
Absolute contraindication: Known or suspected mechanical gastrointestinal obstruction 2, 3, 1
Pediatric warning: Contraindicated in patients less than 2 years of age due to risk of serious dehydration 1
Dose reduction strategy: If diarrhea occurs and is problematic, consider reducing from 145 mcg to 72 mcg for CIC patients 7
Real-World Discontinuation Patterns:
The most common reasons for discontinuation over the first year are loss of efficacy and insurance coverage barriers, not adverse events. 2 In real-world Chinese populations, severe diarrhea was not reported, and most adverse events were mild (89.9%). 8
Duration of Treatment
Clinical trials evaluated treatment for 12 weeks, but the FDA drug label does not provide a limit on treatment duration, allowing for long-term use as needed. 2, 7, 1