AMITIZA Capsule Ref.[10126] Active ingredients: Lubiprostone

5.1 Nausea

Patients taking Amitiza may experience nausea. Concomitant administration of food with Amitiza may reduce symptoms of nausea [see Adverse Reactions (6.1)].

5.2 Diarrhea

Avoid use of Amitiza in patients with severe diarrhea. Patients should be aware of the possible occurrence of diarrhea during treatment. Instruct patients to discontinue Amitiza and contact their healthcare provider if severe diarrhea occurs [see Adverse Reactions (6.1)].

5.3 Syncope and Hypotension

Syncope and hypotension have been reported with Amitiza in the postmarketing setting and a few of these adverse reactions resulted in hospitalization. Most cases occurred in patients taking 24 mcg twice daily and some occurred within an hour after taking the first dose or subsequent doses of Amitiza. Some patients had concomitant diarrhea or vomiting prior to developing the adverse reaction. Syncope and hypotension generally resolved following Amitiza discontinuation or prior to next dose, but recurrence has been reported with subsequent doses. Several cases reported concomitant use of medications known to lower blood pressure, which may increase the risk for the development of syncope or hypotension.

Patients should be aware of the risk of syncope and hypotension during treatment and that other adverse reactions may increase this risk, such as diarrhea or vomiting.

5.4 Dyspnea

In clinical trials, dyspnea was reported by 3%, 1%, and <1% of the treated CIC, OIC, and IBS-C populations receiving Amitiza, respectively, compared to 0%, 1%, and <1% of placebo-treated patients. There have been postmarketing reports of dyspnea when using Amitiza 24 mcg twice daily. Some patients have discontinued treatment because of dyspnea. These events have usually been described as a sensation of chest tightness and difficulty taking in a breath, and generally have an acute onset within 30 to 60 minutes after taking the first dose. They generally resolve within a few hours after taking the dose, but recurrence has been frequently reported with subsequent doses. Instruct patients to contact their healthcare provider if dyspnea occurs.

5.5 Bowel Obstruction

In patients with symptoms suggestive of mechanical gastrointestinal obstruction, perform a thorough evaluation to confirm the absence of an obstruction prior to initiating therapy with Amitiza [see Contraindication (4)].

The following adverse reactions are described below and elsewhere in labeling:

• Nausea [see Warnings and Precautions (5.1)]
• Diarrhea [see Warnings and Precautions (5.2)]
• Syncope and Hypotension [see Warnings and Precautions (5.3)]
• Dyspnea [see Warnings and Precautions (5.4)]

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

During clinical development of Amitiza for CIC, OIC, and IBS-C, 1648 patients were treated with Amitiza for 6 months and 710 patients were treated for 1 year (not mutually exclusive).

Chronic Idiopathic Constipation

Adverse reactions in adult dose-finding, efficacy, and long-term clinical studies: The data described below reflect exposure to Amitiza 24 mcg twice daily in 1113 patients with CIC over 3- or 4-week, 6-month, and 12-month treatment periods; and from 316 patients receiving placebo over short-term exposure (≤4 weeks). The placebo population (N=316) had a mean age of 48 (range 21 to 81) years; was 87% female; 81% Caucasian, 10% African American, 7% Hispanic, 1% Asian, and 12% elderly (≥65 years of age). Of those patients treated with Amitiza 24 mcg twice daily (N=1113), the mean age was 50 (range 19-86) years; 87% were female; 86% Caucasian, 8% African American, 5% Hispanic, 1% Asian, and 17% elderly (≥65 years of age).

The most common adverse reactions (>4%) in CIC were nausea, diarrhea, headache, abdominal pain, abdominal distension, and flatulence.

Table 2 presents data for the adverse reactions that occurred in at least 1% of patients and that occurred more frequently with Amitiza than placebo.

Table 2. Adverse Reactions* in Clinical Trials of Adults with CIC:

* Reported in at least 1% of patients treated with Amitiza and greater than placebo
^† This term combines “abdominal tenderness,” “abdominal rigidity,” “gastrointestinal discomfort,” “stomach discomfort”, and "abdominal discomfort."

Nausea: Approximately 29% of patients who received Amitiza experienced nausea; 4% of patients had severe nausea and 9% of patients discontinued treatment due to nausea. The rate of nausea was lower among male (8%) and elderly (19%) patients. No patients in the clinical studies were hospitalized due to nausea.

Diarrhea: Approximately 12% of patients who received Amitiza experienced diarrhea; 2% of patients had severe diarrhea and 2% of patients discontinued treatment due to diarrhea.

Electrolytes: No serious adverse reactions of electrolyte imbalance were reported in clinical studies, and no clinically significant changes were seen in serum electrolyte levels in patients receiving Amitiza.

Less common adverse reactions (<1%): fecal incontinence, muscle cramp, defecation urgency, frequent bowel movements, hyperhidrosis, pharyngolaryngeal pain, intestinal functional disorder, anxiety, cold sweat, constipation, cough, dysgeusia, eructation, influenza, joint swelling, myalgia, pain, syncope, tremor, decreased appetite.

Opioid-Induced Constipation

Adverse reactions in adult efficacy and long-term clinical studies: The data described below reflect exposure to Amitiza 24 mcg twice daily in 860 patients with OIC for up to 12 months and from 632 patients receiving placebo twice daily for up to 12 weeks. The total population (N=1492) had a mean age of 50 (range 20–89) years; was 63% female; 83% Caucasian, 14% African American, 1% American Indian/Alaska Native, 1% Asian; 5% were of Hispanic ethnicity, and 9% were elderly (≥65 years of age).

The most common adverse reactions (>4%) in OIC were nausea and diarrhea.

Table 3 presents data for the adverse reactions that occurred in at least 1% of patients and that occurred more frequently with study drug than placebo.

Table 3. Adverse Reactions* in Clinical Trials of Adults with OIC:

* Reported in at least 1% of patients treated with Amitiza and greater than placebo
^† This term combines “abdominal tenderness,” “abdominal rigidity,” “gastrointestinal discomfort,” “stomach discomfort”, and "abdominal discomfort."

Nausea: Approximately 11% of patients who received Amitiza experienced nausea; 1% of patients had severe nausea and 2% of patients discontinued treatment due to nausea.

Diarrhea: Approximately 8% of patients who received Amitiza experienced diarrhea; 2% of patients had severe diarrhea and 1% of patients discontinued treatment due to diarrhea.

Less common adverse reactions (<1%): fecal incontinence, blood potassium decreased.

Irritable Bowel Syndrome with Constipation

Adverse reactions in adult dose-finding, efficacy, and long-term clinical studies: The data described below reflect exposure to Amitiza 8 mcg twice daily in 1011 patients with IBS-C for up to 12 months and from 435 patients receiving placebo twice daily for up to 16 weeks. The total population (N=1267) had a mean age of 47 (range 18–85) years; was 92% female; 78% Caucasian, 13% African American, 9% Hispanic, 0.4% Asian, and 8% elderly (≥65 years of age).

The most common adverse reactions (>4%) in IBS-C were nausea, diarrhea, and abdominal pain.

Table 4 presents data for the adverse reactions that occurred in at least 1% of patients and that occurred more frequently with study drug than placebo.

Table 4. Adverse Reactions* in Clinical Trials of Adults with IBS-C:

* Reported in at least 1% of patients treated with Amitiza and greater than placebo

Nausea: Approximately 8% of patients who received Amitiza 8 mcg twice daily experienced nausea; 1% of patients had severe nausea and 1% of patients discontinued treatment due to nausea.

Diarrhea: Approximately 7% of patients who received Amitiza 8 mcg twice daily experienced diarrhea; <1% of patients had severe diarrhea and <1% of patients discontinued treatment due to diarrhea.

Less common adverse reactions (<1%): dyspepsia, loose stools, vomiting, fatigue, dry mouth, edema, increased alanine aminotransferase, increased aspartate aminotransferase, constipation, eructation, gastroesophageal reflux disease, dyspnea, erythema, gastritis, increased weight, palpitations, urinary tract infection, anorexia, anxiety, depression, fecal incontinence, fibromyalgia, hard feces, lethargy, rectal hemorrhage, pollakiuria.

The following additional adverse reactions have been identified during post-approval use of Amitiza. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Cardiovascular: syncope and/or hypotension [see Warnings and Precautions (5.3)], tachycardia

Gastrointestinal: ischemic colitis

General: asthenia

Immune System: hypersensitivity reactions including rash, swelling, and throat tightness malaise

Muscoskeletal: muscle cramps or muscle spasms.

7.1 Methadone

Diphenylheptane opioids (e.g., methadone) have been shown in nonclinical studies to dose-dependently reduce the activation of ClC-2 by lubiprostone in the gastrointestinal tract. There is a possibility of a dose-dependent decrease in the efficacy of Amitiza in patients using diphenylheptane opioids. No in vivo interaction studies have been conducted.

The effectiveness of Amitiza in the treatment of OIC in patients taking diphenylhepatane opioids (e.g., methadone) has not been established [see Indications and Usage (1.2)].

Risk Summary

Following oral administration, concentrations of lubiprostone in plasma are below the level of quantitation; however, one of the metabolites, M3, has measurable systemic concentrations [see Clinical Pharmacology (12.3)]. Limited available data with lubiprostone use in pregnant women are insufficient to inform a drug associated risk of adverse developmental outcomes. Animal reproduction studies did not show an increase in structural malformations. Although a dose dependent increase in fetal loss was observed in pregnant guinea pigs that received lubiprostone (doses equivalent to 0.2 to 6 times the maximum recommended human dose (MRHD) based on body surface area (mg/m²)), these effects were probably secondary to maternal toxicity and occurred after the period of organogenesis (see Data).

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Data

Animal Data

In developmental toxicity studies, pregnant rats and rabbits received oral lubiprostone during organogenesis at doses up to approximately 338 times (rats) and approximately 34 times (rabbits) the maximum recommended human dose (MRHD) based on body surface area (mg/m²). Maximal animal doses were 2000 mcg/kg/day (rats) and 100 mcg/kg/day (rabbits). In rats, there were increased incidences of early resorptions and soft tissue malformations (situs inversus, cleft palate) at the 2000 mcg/kg/day dose; however, these effects were probably secondary to maternal toxicity. A dose-dependent increase in fetal loss occurred when guinea pigs received lubiprostone after the period of organogenesis, on days 40 to 53 of gestation, at daily oral doses of 1, 10, and 25 mcg/kg/day (approximately 0.2, 2 and 6 times the MRHD based on body surface area (mg/m²)); however, these effects were probably secondary to maternal toxicity. The potential of lubiprostone to cause fetal loss was also examined in pregnant rhesus monkeys. Monkeys received lubiprostone post-organogenesis on gestation days 110 through 130 at daily oral doses of 10 and 30 mcg/kg/day (approximately 3 and 10 times the MRHD based on body surface area (mg/m²)). Fetal loss was noted in one monkey from the 10-mcg/kg dose group, which is within normal historical rates for this species. There was no drug-related adverse effect seen in monkeys.

Risk Summary

There are no data available on the presence of lubiprostone in human milk or the effect of lubiprostone on milk production. There are limited data available on the effect of lubiprostone on the breastfed infant. Neither lubiprostone nor its active metabolite (M3) were present in the milk of lactating rats. When a drug is not present in animal milk, it is likely that the drug will not be present in human milk. If present, lubiprostone may cause diarrhea in the breastfed infant (see Clinical Considerations). The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Amitiza and any potential adverse effects on the breastfed infant from Amitiza or from the underlying maternal condition.

Clinical Considerations

Infants of nursing mothers being treated with Amitiza should be monitored for diarrhea.

Safety and effectiveness have not been established in pediatric patients less than 6 years of age.

Effectiveness has not been established in pediatric patients 6 years and older. Efficacy was not demonstrated for the treatment of Pediatric Functional Constipation (PFC) in a 12 week, randomized, double-blind, placebo controlled trial conducted in 606 patients 6 to 17 years with PFC comparing Amitiza to placebo. The primary efficacy endpoint was an overall response based on spontaneous bowel movement frequency over the duration of the trial; the treatment difference from placebo was not statistically significant. In this age group, adverse reactions to Amitiza were similar to those reported in adults. In a 36-week, long-term safety extension trial after approximately 9 months of treatment with Amitiza, a single case of reversible elevation of ALT (17-times upper limit of normal [ULN]), AST (13-times ULN), and GGT (9-times [ULN]) was observed in a child with baseline elevated values (less than or equal to 2.5-times ULN).

Juvenile Animal Toxicity Data

In a 13-week oral toxicity study in juvenile rats, a significant decrease in total bone mineral density was observed in female pups at 0.5 mg/kg/day; in male pups, a significantly lower cortical thickness at the tibial diaphysis was observed at 0.5 mg/kg. The 0.5 mg/kg/day dose is approximately 101 times the maximum recommended adult dose of 48 mcg/day, based on body surface area (mg/m²).

Chronic Idiopathic Constipation

The efficacy of Amitiza 24 mcg twice daily in the elderly (at least 65 years of age) subpopulation with CIC was consistent with the efficacy in the overall study population. Of the total number of patients treated in the dose-finding, efficacy, and long-term studies of Amitiza, 16% were at least 65 years of age, and 4% were at least 75 years of age. Elderly patients taking Amitiza experienced a lower rate of associated nausea compared to the overall study population taking Amitiza (19% vs. 29%, respectively).

Opioid-Induced Constipation

The safety profile of Amitiza in the elderly (at least 65 years of age) subpopulation with OIC (9% were at least 65 years of age and 2% were at least 75 years of age) was consistent with the safety profile in the overall study population. Clinical studies of Amitiza did not include sufficient numbers of patients aged 65 years and over to determine whether they respond differently from younger patients.

Irritable Bowel Syndrome with Constipation

The safety profile of Amitiza in the elderly (at least 65 years of age) subpopulation with IBS-C (8% were at least 65 years of age and 2% were at least 75 years of age) was consistent with the safety profile in the overall study population. Clinical studies of Amitiza did not include sufficient numbers of patients aged 65 years and over to determine whether they respond differently from younger patients.

Patients with moderate hepatic impairment (Child-Pugh Class B) and severe hepatic impairment (Child-Pugh Class C) experienced markedly higher systemic exposure of lubiprostone active metabolite M3, when compared to subjects with normal hepatic function [see Clinical Pharmacology (12.3)]. Clinical safety results demonstrated an increased incidence and severity of adverse events in subjects with greater severity of hepatic impairment.

Adjust the dosage of Amitiza in patients with severe hepatic impairment for all indications. Dosage adjustment is also needed for patients with moderate hepatic impairment treated for CIC, and OIC [see Dosage and Administration (2.1)]. No dosing adjustment is required in patients with mild hepatic impairment (Child-Pugh Class A).