Lubiprostone

1 INDICATIONS AND USAGE Lubiprostone is a chloride channel activator indicated for the treatment of: chronic idiopathic constipation (CIC) in adults. ( 1.1 ) 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. ( 1.2 ) Limitations of Use: Effectiveness of lubiprostone in the treatment of OIC in patients taking diphenylheptane opioids (e.g., methadone) has not been established. ( 1.2 , 7.1 ) irritable bowel syndrome with constipation (IBS-C) in women ≥ 18 years old. ( 1.3 ) 1.1 Chronic Idiopathic Constipation in Adults Lubiprostone is 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 is 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 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 is indicated for the treatment of irritable bowel syndrome with constipation (IBS-C) in women at least 18 years old.

12.1 Mechanism of Action Lubiprostone is a locally acting chloride channel activator that enhances a chloride-rich intestinal fluid secretion without altering sodium and potassium concentrations in the serum. Lubiprostone acts by specifically activating ClC-2, which is a normal constituent of the apical membrane of the human intestine, in a protein kinase A–independent fashion. By increasing intestinal fluid secretion, lubiprostone increases motility in the intestine, thereby facilitating the passage of stool and alleviating symptoms associated with chronic idiopathic constipation. Patch clamp cell studies in human cell lines have indicated that the majority of the beneficial biological activity of lubiprostone and its metabolites is observed only on the apical (luminal) portion of the gastrointestinal epithelium. Lubiprostone, via activation of apical ClC-2 channels in intestinal epithelial cells, bypasses the antisecretory action of opiates that results from suppression of secretomotor neuron excitability. Activation of ClC-2 by lubiprostone has also been shown to stimulate recovery of mucosal barrier function and reduce intestinal permeability via the restoration of tight junction protein complexes in ex vivo studies of ischemic porcine intestine.

2 DOSAGE AND ADMINISTRATION Recommended Dosage ( 2.1 ) CIC and OIC: 24 mcg twice daily. IBS-C: 8 mcg twice daily. See full prescribing information for dosage adjustment by indication and degree of hepatic impairment. Administration Instructions ( 2.2 ) Swallow capsules whole and do not break apart or chew, Take capsules with food and water, Assess periodically the need for continuous therapy. 2.1 Recommended Dosage The recommended oral dosage of lubiprostone 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 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. 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 2.2 Administration Instructions Take lubiprostone 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.

6 ADVERSE REACTIONS 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) ] Most common adverse reactions (> 4%) are: CIC: nausea, diarrhea, headache, abdominal pain, abdominal distension, and flatulence. ( 6.1 ) OIC: nausea and diarrhea. ( 6.1 ) IBS-C: nausea, diarrhea, and abdominal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Dr. Reddy's Laboratories Inc. at 1-888-375-3784 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 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, 1648 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 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 lubiprostone 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 lubiprostone than placebo. Table 2. Adverse Reactions Reported in at least 1% of patients treated with lubiprostone and greater than placebo in Clinical Trials of Adults with CIC System/Adverse Reaction Placebo lubiprostone 24 mcg Twice Daily N = 316 % N = 1113 % 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 discomfort This term combines "abdominal tenderness," "abdominal rigidity," "gastrointestinal discomfort," "stomach discomfort", and "abdominal discomfort." 1 3 Dizziness 1 3 Chest discomfort/pain 0 2 Dyspnea 0 2 Dyspepsia <1 2 Fatigue 1 2 Dry mouth <1 1 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 studi

5 WARNINGS AND PRECAUTIONS Nausea : Patients may experience nausea; concomitant administration of food may reduce this symptom. ( 2.2 , 5.1 ) Diarrhea : Avoid use in patients with severe diarrhea. Instruct patients to discontinue lubiprostone and contact their healthcare provider if severe diarrhea occurs during treatment. ( 5.2 ) Syncope and Hypotension : May occur after taking the first dose or with subsequent doses. Generally resolves prior to the next dose, but may recur with repeat dosing. Instruct patients to discontinue lubiprostone and contact their healthcare provider if symptoms occur. ( 5.3 ) Dyspnea : May occur within an hour of first dose. Generally resolves within 3 hours, but may recur with repeat dosing. Instruct patients to contact their healthcare provider if symptoms occur. ( 5.4 ) Bowel Obstruction : Evaluate patients with symptoms suggestive of mechanical gastrointestinal obstruction prior to initiating treatment with lubiprostone. ( 4 , 5.5 ) 5.1 Nausea Patients taking lubiprostone may experience nausea. Concomitant administration of food with lubiprostone may reduce symptoms of nausea [ see Adverse Reactions (6.1) ] . 5.2 Diarrhea Avoid use of lubiprostone in patients with severe diarrhea. Patients should be aware of the possible occurrence of diarrhea during treatment. Instruct patients to discontinue lubiprostone 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 lubiprostone 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 lubiprostone. Some patients had concomitant diarrhea or vomiting prior to developing the adverse reaction. Syncope and hypotension generally resolved following lubiprostone 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 lubiprostone, respectively, compared to 0%, 1%, and < 1% of placebo-treated patients. There have been postmarketing reports of dyspnea when using lubiprostone 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 lubiprostone [see Contraindication (4) ] .

4 CONTRAINDICATIONS Lubiprostone is contraindicated in patients with known or suspected mechanical gastrointestinal obstruction [see Warnings and Precautions (5.5) ] . Patients with known or suspected mechanical gastrointestinal obstruction. ( 4 , 5.5 )

10 OVERDOSAGE There have been six reports of overdosage with lubiprostone during clinical development. Of these six cases, only two subjects reported adverse events: one reported vomiting, diarrhea and stomach ache after taking 168 to 192 mcg of lubiprostone, and another reported diarrhea and a joint injury on the day of overdose after taking 36 mcg of lubiprostone. Adverse reactions that occurred in at least 1% of healthy subjects given a single oral dose of 144 mcg of lubiprostone (6 times the highest recommended dose) in a cardiac repolarization study included nausea (45%), diarrhea (35%), vomiting (27%), dizziness (14%), headache (12%), abdominal pain (8%), flushing/hot flash (8%), retching (8%), dyspnea (4%), pallor (4%), stomach discomfort (4%), anorexia (2%), asthenia (2%), chest discomfort (2%), dry mouth (2%), hyperhidrosis (2%), and syncope (2%).