Amitiza and Linzess are both prescription medications used to treat chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C). They belong to a class of drugs known as guanylate cyclase-C (GC-C) agonists, which work by increasing the secretion of fluid into the intestines, making stool easier to pass.
While Amitiza and Linzess have similar mechanisms of action, they differ in several ways, including their formulations, dosages, side effects, and efficacy. In this article, we will compare and contrast these two medications in detail, examining their similarities and differences to help patients and healthcare providers make informed decisions about which medication may be more appropriate for their individual needs.
Amitiza vs Linzess (Formulation)
Amitiza is available in two formulations: a 24 mcg capsule and an 8 mcg capsule. The 24 mcg capsule is indicated for the treatment of CIC in adults, while the 8 mcg capsule is indicated for the treatment of IBS-C in women. Both formulations are taken orally twice daily with food.
Linzess, on the other hand, is available in only one formulation: a 290 mcg capsule. It is indicated for the treatment of both CIC and IBS-C in adults and is taken orally once daily, either with or without food.
Dosage
The recommended starting dose for Amitiza is 24 mcg twice daily for the treatment of CIC and 8 mcg twice daily for the treatment of IBS-C. If the desired effect is not achieved, the dosage may be increased to a maximum of 48 mcg twice daily for CIC and 24 mcg twice daily for IBS-C.
The recommended dosage for Linzess is 290 mcg once daily, regardless of whether it is being used to treat CIC or IBS-C. The dosage may be adjusted up to a maximum of 290 mcg twice daily, but this is typically not necessary.
It is important to note that Amitiza and Linzess are not interchangeable, as they have different dosing regimens and different indications.
Amitiza vs Linzess (Side Effects)
Both Amitiza and Linzess can cause similar side effects, such as nausea, diarrhea, and abdominal pain. However, the incidence and severity of these side effects can vary between the two medications.
Amitiza is known to cause more frequent and severe diarrhea compared to Linzess. In clinical trials, approximately 30% of patients taking Amitiza experienced diarrhea, while only 7% of patients taking Linzess experienced this side effect. In addition, Amitiza can cause headaches, which are not commonly reported with Linzess.
Linzess, on the other hand, is more likely to cause abdominal pain and discomfort than Amitiza. In clinical trials, approximately 6% of patients taking Linzess experienced abdominal pain, while only 3% of patients taking Amitiza experienced this side effect. In addition, Linzess can cause flatulence, which is not commonly reported with Amitiza.
Efficacy
Both Amitiza and Linzess have been shown to be effective in treating CIC and IBS-C, but the degree of efficacy can vary between the two medications.
In clinical trials, Amitiza has been shown to increase the frequency of bowel movements and improve stool consistency in patients with CIC. In one study, approximately 17% of patients taking Amitiza experienced a significant improvement in their symptoms compared to 10% of patients taking a placebo.
In patients with IBS-C, Amitiza has been shown to improve overall symptoms and increase the frequency of bowel movements. In one study, approximately 27% of patients taking Amitiza experienced a significant improvement in their symptoms compared to 18% of patients taking a placebo.
Linzess has also been shown to increase the frequency of bowel movements and improve stool consistency in patients with CIC. In one study, approximately 21% of patients taking Linzess experienced a significant improvement in their symptoms compared to 10% of patients taking a placebo.
In patients with IBS-C, Linzess has been shown to improve overall symptoms, including abdominal pain and discomfort, and increase the frequency of bowel movements. In one study, approximately 34% of patients taking Linzess experienced a significant improvement in their symptoms compared to 19% of patients taking a placebo.
It is important to note that the efficacy of these medications may vary depending on the individual patient and the severity of their condition. In some cases, patients may need to try both medications before finding the one that works best for them.
Cost
The cost of Amitiza and Linzess can vary depending on factors such as insurance coverage and the pharmacy where the medication is purchased. However, in general, Linzess tends to be more expensive than Amitiza.
The average retail price for a 30-day supply of Amitiza is approximately $500, while the average retail price for a 30-day supply of Linzess is approximately $700. However, many insurance plans may cover a portion of the cost of these medications, which can help to make them more affordable.
Amitiza – Clinical Research Studies
Amitiza, also known by its generic name lubiprostone, was approved by the U.S. Food and Drug Administration (FDA) in 2006 for the treatment of CIC in adults. Since then, numerous clinical trials have been conducted to evaluate its safety and efficacy.
One study published in the New England Journal of Medicine in 2008 looked at the efficacy of Amitiza in 1,154 patients with CIC. The study found that patients who took Amitiza had a significantly greater improvement in spontaneous bowel movements (SBMs) than those who took a placebo. Additionally, Amitiza was well-tolerated and had a low incidence of adverse events.
Another study published in the American Journal of Gastroenterology in 2011 evaluated the efficacy of Amitiza in 620 patients with IBS-C. The study found that patients who took Amitiza had a significantly greater improvement in SBMs, stool consistency, and overall symptoms compared to those who took a placebo. The study also found that Amitiza was generally well-tolerated.
Linzess – Clinical Research Studies
Linzess, also known by its generic name linaclotide, was approved by the FDA in 2012 for the treatment of CIC and IBS-C in adults. Like Amitiza, Linzess has been extensively studied in clinical trials.
One study published in the New England Journal of Medicine in 2011 evaluated the efficacy of Linzess in 800 patients with CIC. The study found that patients who took Linzess had a significantly greater improvement in SBMs and stool consistency compared to those who took a placebo. Additionally, Linzess was generally well-tolerated with a low incidence of adverse events.
Another study published in the American Journal of Gastroenterology in 2012 evaluated the efficacy of Linzess in 800 patients with IBS-C. The study found that patients who took Linzess had a significantly greater improvement in overall symptoms, abdominal pain and discomfort, and SBMs compared to those who took a placebo. The study also found that Linzess was generally well-tolerated with a low incidence of adverse events.
Overall, both Amitiza and Linzess have been shown to be effective in treating CIC and IBS-C in clinical trials, with low incidences of adverse events. However, it is important to note that individual patient responses may vary, and patients should talk to their healthcare provider to determine which medication may be the most appropriate choice for them.
Conclusion
Amitiza and Linzess are both medications used to treat CIC and IBS-C, and they have similar mechanisms of action. However, they differ in several ways, including their formulations, dosages, side effects, and efficacy. Patients and healthcare providers should consider these factors when deciding which medication may be more appropriate for their individual needs.
While both medications have been shown to be effective in treating CIC and IBS-C, the choice of medication may ultimately depend on factors such as the patient’s specific symptoms, medical history, and overall health. Patients should talk to their healthcare provider to determine which medication may be the most appropriate choice for them, taking into consideration the potential benefits and risks of each medication.
Amitiza and Linzess are two medications that have been extensively studied in clinical trials for their efficacy and safety in treating chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C).
