From the Guidelines
Amitiza (lubiprostone) is a medication that helps relieve constipation symptoms, abdominal discomfort, and bloating associated with irritable bowel syndrome with constipation (IBS-C) by increasing fluid secretion in the small intestine. The standard dose for IBS-C is 8 micrograms taken twice daily with food and water, as recommended by the AGA clinical practice guideline on the pharmacological management of irritable bowel syndrome with constipation 1. Amitiza specifically targets chloride channels in the intestinal lining, activating them to increase intestinal fluid, which helps move stool through the digestive tract more easily. This mechanism helps relieve constipation symptoms, abdominal discomfort, and bloating associated with IBS-C. Common side effects include nausea, diarrhea, and headache, as reported in the british society of gastroenterology guidelines on the management of irritable bowel syndrome 1. The medication typically begins working within 24-48 hours, though full benefits may take 1-2 weeks to develop. Patients should take Amitiza consistently as prescribed and inform their doctor if they experience severe side effects or if symptoms don't improve after several weeks of treatment. Some key points to consider when prescribing Amitiza include:
- The AGA suggests using lubiprostone as a conditional recommendation for patients with IBS-C, with moderate certainty of evidence 1.
- Lubiprostone 8 μg two times per day was superior to placebo for both the FDA composite end point for IBS-C and abdominal pain alone, as reported in the british society of gastroenterology guidelines on the management of irritable bowel syndrome 1.
- Adverse events were no more common with lubiprostone, except for nausea, as reported in the same guidelines 1. It is essential to weigh the benefits and risks of Amitiza and consider alternative treatments, such as linaclotide, which has a strong recommendation and high certainty of evidence for patients with IBS-C 1.
From the FDA Drug Label
1.3 Irritable Bowel Syndrome with Constipation Lubiprostone is indicated for the treatment of irritable bowel syndrome with constipation (IBS-C) in women at least 18 years old.
Amitiza (lubiprostone) is used to treat Irritable Bowel Syndrome with Constipation (IBS-C) in women at least 18 years old 2.
- It works by increasing intestinal fluid secretion, which helps to facilitate the passage of stool and alleviate symptoms associated with IBS-C.
- The recommended oral dosage of lubiprostone for IBS-C is 8 mcg twice daily 2.
- Key benefits of lubiprostone for IBS-C include increased motility in the intestine and alleviation of symptoms associated with the condition 2.
From the Research
Mechanism of Action
- Amitiza (Lubiprostone) is a type 2 chloride channel activator that increases fluid secretion in the intestinal apical cell membrane, increasing gut motility and frequency of stool passage, and alleviating abdominal discomfort/pain 3, 4.
- It also stimulates the secretion of chloride, sodium, and water into the lumen, causing luminal distension, secondary peristalsis, and laxation 5.
Efficacy in IBS-C
- Clinical trial data have shown that Amitiza is efficacious in the treatment of chronic idiopathic constipation and irritable bowel syndrome with constipation (IBS-C) 3, 4, 5, 6.
- Studies have demonstrated that Amitiza increases spontaneous bowel movement frequency, improves stool consistency, and reduces straining, bloating, and severity of constipation 4, 6.
- The beneficial effects of Amitiza can continue for up to 4 weeks after cessation of treatment 4.
Safety and Tolerability
- Amitiza is generally considered to be safe and effective, with common side effects including nausea, diarrhea, abdominal pain, and bloating 4, 5, 7, 6.
- The incidence of serious adverse effects is low (<5%) and is mostly unrelated to Amitiza treatment 6.
- Amitiza acts topically in the gut lumen and is almost completely metabolized in the gut lumen, with its M3 metabolite being detectable in low concentrations in the serum 7.