AMITZA

Lubiprostone is a chloride channel activator for oral use. The chemical name for lubiprostone is (–)-7-[(2R,4aR,5R,7aR)-2-(1,1-difluoropentyl)-2-hydroxy-6-oxooctahydrocyclopenta[b]pyran-5-yl]heptanoic acid. The molecular formula of lubiprostone is C20H32F2O5 with a molecular weight of 390.47 and a chemical structure as follows: [1] Lubiprostone drug substance occurs as off-white to white crystalline powder, is very soluble in ether and ethanol, and is practically insoluble in hexane and water. Lubiprostone capsules are available as imprinted, oval, soft gelatin capsules in two strengths. Pink capsules contain 8 mcg of lubiprostone and the following inactive ingredients: black iron oxide, ferric oxide red, gelatin, hypromellose, lecithin, medium-chain triglycerides, propylene glycol, purified water, sorbitol sorbitan solution, and titanium dioxide. Orange capsules contain 24 mcg of lubiprostone and the following inactive ingredients: black iron oxide, D&C Yellow No. 10, FD&C Red No. 40, gelatin, hypromellose, lecithin, medium-chain triglycerides, propylene glycol, purified water, and sorbitol sorbitan solution.

1 Chronic Idiopathic Constipation in Adults Lubiprostone capsules are indicated for the treatment of chronic idiopathic constipation (CIC) in adults. 1.2 Opioid-Induced Constipation in Adult Patients with Chronic Non-Cancer Pain Lubiprostone capsules are indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain, including patients with chronic pain related to prior cancer or its treatment who do not require frequent (e.g., weekly) opioid dosage escalation. Limitations of Use: Effectiveness of lubiprostone capsules in the treatment of opioid-induced constipation in patients taking diphenylheptane opioids (e.g., methadone) has not been established [see Clinical Studies (14.2)]. 1.3 Irritable Bowel Syndrome with Constipation Lubiprostone capsules are indicated for the treatment of irritable bowel syndrome with constipation (IBS-C) in women at least 18 years old.

1 Recommended Dosage The recommended oral dosage of lubiprostone capsules by indication and adjustments for patients with moderate (Child Pugh Class B) and severe (Child Pugh Class C) hepatic impairment are shown in Table 1. Table 1. Recommended Dosage Regimen CIC and OIC IBS-C Recommended Adult Dosage Regimen 24 mcg twice daily 8 mcg twice daily Dosage Adjustment for Hepatic Impairment [see Use in Specific Populations (8.6)] Moderate Impairment (Child-Pugh Class B): 16 mcg twice daily* Moderate Impairment (Child-Pugh Class B): No adjustment necessary Severe Impairment (Child-Pugh Class C): 8 mcg twice daily* Severe Impairment (Child-Pugh Class C): 8 mcg once daily* *If the dose is tolerated and an adequate response has not been obtained after an appropriate interval, doses can then be escalated to full dosing with appropriate monitoring of patient response. 2.2 Administration Instructions Take lubiprostone capsules orally with food and water. Swallow capsules whole and do not break apart or chew. Physicians and patients should periodically assess the need for continued therapy.

Lubiprostone is contraindicated in patients with known or suspected mechanical gastrointestinal obstruction [see Warnings and Precautions (5.5)].

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)] 6.1 Clinical Trials Experience 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 lubiprostone for CIC, OIC, and IBS-C, 1,648 patients were treated with lubiprostone 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 lubiprostone 24 mcg twice daily in 1,113 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 lubiprostone 24 mcg twice daily (N=1,113), the mean age was 50 (range 19 to 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 lubiprostone than placebo. Table 2. Adverse Reactions1 in Clinical Trials of Adults with CIC System/Adverse Reaction Placebo N=316 % Lubiprostone 24 mcg Twice Daily N=1,113 % Nausea 3 29 Diarrhea 1 12 Headache 5 11 Abdominal pain 3 8 Abdominal distension 2 6 Flatulence 2 6 Vomiting 0 3 Loose stools 0 3 Edema <1 3 Abdominal discomfort2 1 3 Dizziness 1 3 Chest discomfort/pain 0 2 Dyspnea 0 2 Dyspepsia <1 2 Fatigue 1 2 Dry mouth <1 1 1 Reported in at least 1% of patients treated with lubiprostone and greater than placebo 2 This term combines “abdominal tenderness,” “abdominal rigidity,” “gastrointestinal discomfort,” “stomach discomfort”, and “abdominal discomfort.” Nausea: Approximately 29% of patients who received lubiprostone 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 lubiprostone 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 lubiprostone. 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 lubiprostone 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=1,492) had a mean age of 50 (range 20 to 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 Reactions1 in Clinical Trials of Adults with OIC System/Adverse Reaction1 Placebo N=632 % Lubiprostone 24 mcg Twice Daily N=860 % Nausea 5 11 Diarrhea 2 8 Abdominal pain 1 4 Flatulence 3 4 Abdominal distension 2 3 Vomiting 2 3 Headache 1 2 Peripheral edema <1 1 Abdominal discomfort2 1 1 1 Reported in at least 1% of patients treated with lubiprostone and greater than placebo 2 This term combines “abdominal tenderness,” “abdominal rigidity,” “gastrointestinal discomfort,” “stomach discomfort”, and “abdominal discomfort.” Nausea: Approximately 11% of patients who received lubiprostone experienced nausea; 1% of patients had severe nausea and 2% of patients discontinued treatment due to nausea. Diarrhea: Approximately 8% of patients who received lubiprostone 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 lubiprostone 8 mcg twice daily in 1,011 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=1,267) had a mean age of 47 (range 18 to 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 Reactions1 in Clinical Trials of Adults with IBS-C System/Adverse Reaction Placebo N=435 % Lubiprostone 8 mcg Twice Daily N=1,011 % Nausea 4 8 Diarrhea 4 7 Abdominal pain 5 5 Abdominal distension 2 3 1 Reported in at least 1% of patients treated with lubiprostone and greater than placebo Nausea: Approximately 8% of patients who received lubiprostone 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 lubiprostone 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. 6.2 Postmarketing Experience The following additional adverse reactions have been identified during post-approval use of lubiprostone. 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 Musculoskeletal: muscle cramps or muscle spasms.

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 lubiprostone in patients using diphenylheptane opioids. No in vivo interaction studies have been conducted. The effectiveness of lubiprostone in the treatment of OIC in patients taking diphenylhepatane opioids (e.g., methadone) has not been established [see Indications and Usage (1.2)].

Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light and extreme temperatures.