Rabeprazole

12.1 Mechanism of Action Rabeprazole belongs to a class of antisecretory compounds (substituted benzimidazole proton-pump inhibitors) that do not exhibit anticholinergic or histamine H 2 -receptor antagonist properties, but suppress gastric acid secretion by inhibiting the gastric H + , K + ATPase at the secretory surface of the gastric parietal cell. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, rabeprazole has been characterized as a gastric proton-pump inhibitor. Rabeprazole blocks the final step of gastric acid secretion. In gastric parietal cells, rabeprazole is protonated, accumulates, and is transformed to an active sulfenamide. When studied in vitro , rabeprazole is chemically activated at pH 1.2 with a half-life of 78 seconds. It inhibits acid transport in porcine gastric vesicles with a half-life of 90 seconds.

1 INDICATIONS AND USAGE Rabeprazole sodium delayed-release tablets is a proton pump inhibitor (PPI) indicated in adults for: Healing of Erosive or Ulcerative Gastroesophageal Reflux Disease (GERD) ( 1.1 ). Maintenance of Healing of Erosive or Ulcerative GERD ( 1.2 ). Treatment of Symptomatic GERD ( 1.3 ). Healing of Duodenal Ulcers ( 1.4 ). Helicobacter pylori Eradication to Reduce Risk of Duodenal Ulcer Recurrence ( 1.5 ). Treatment of Pathological Hypersecretory Conditions, Including Zollinger-Ellison Syndrome ( 1.6 ). In adolescent patients 12 years of age and older for: Short-term Treatment of Symptomatic GERD ( 1.7 ). 1.1 Healing of Erosive or Ulcerative GERD in Adults Rabeprazole sodium delayed-release tablets are indicated for short-term (4 to 8 weeks) treatment in the healing and symptomatic relief of erosive or ulcerative gastroesophageal reflux disease (GERD). For those patients who have not healed after 8 weeks of treatment, an additional 8-week course of rabeprazole sodium delayed-release tablets may be considered. 1.2 Maintenance of Healing of Erosive or Ulcerative GERD in Adults Rabeprazole sodium delayed-release tablets are indicated for maintaining healing and reduction in relapse rates of heartburn symptoms in patients with erosive or ulcerative gastroesophageal reflux disease (GERD Maintenance). Controlled studies do not extend beyond 12 months. 1.3 Treatment of Symptomatic GERD in Adults Rabeprazole sodium delayed-release tablets are indicated for the treatment of daytime and nighttime heartburn and other symptoms associated with GERD in adults for up to 4 weeks. 1.4 Healing of Duodenal Ulcers in Adults Rabeprazole sodium delayed-release tablets are indicated for short-term (up to four weeks) treatment in the healing and symptomatic relief of duodenal ulcers. Most patients heal within four weeks. 1.5 Helicobacter pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence in Adults Rabeprazole sodium delayed-release tablets, in combination

2 DOSAGE AND ADMINISTRATION Indication Recommended Dosage ( 2 ) Healing of Erosive or Ulcerative Gastroesophageal Reflux Disease (GERD) 20 mg once daily for 4 to 8 weeks Maintenance of Healing of Erosive or Ulcerative GERD* studied for 12 months 20 mg once daily* Symptomatic GERD in Adults 20 mg once daily for 4 weeks Healing of Duodenal Ulcers 20 mg once daily after morning meal for up to 4 weeks Helicobacter pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence Three Drug Regimen: Rabeprazole sodium delayed-release tablets 20 mg Amoxicillin 1,000 mg Clarithromycin 500 mg All three medications should be taken twice daily with morning and evening meals for 7 days. Pathological Hypersecretory Conditions, Including Zollinger-Ellison Syndrome Starting dose 60 mg once daily then adjust to patient needs Symptomatic GERD in Adolescents 12 Years of Age and Older 20 mg once daily for up to 8 weeks Administration Instructions ( 2 ) : Swallow rabeprazole sodium delayed-release tablets whole. Do not chew, crush or split the tablets. For the treatment of duodenal ulcers take rabeprazole sodium delayed-release tablets after a meal. For Helicobacter pylori eradication take rabeprazole sodium delayed-release tablets with food. For all other indications rabeprazole sodium delayed-release tablets can be taken with or without food. Table 1 shows the recommended dosage of rabeprazole sodium delayed-release tablets in adults and adolescent patients 12 years of age and older. The use of rabeprazole sodium delayed-release tablets is not recommended for use in pediatric patients 1 year to less than 12 years of age because the lowest available tablet strength (20 mg) exceeds the recommended dose for these patients. Use another rabeprazole formulation for pediatric patients 1 year to less than 12 years of age. Table 1: Recommended Dosage and Duration of Rabeprazole Sodium Delayed-Release Tablets in Adults and Adolescents 12 Years of Age and Older * For those patients who have not healed after 8 weeks of treatment, an additional 8-week course of rabeprazole sodium delayed-release tablets may be considered. ** If symptoms do not resolve completely after 4 weeks, an additional course of treatment may be considered. *** Most patients heal within 4 weeks; some patients may require additional therapy to achieve healing. Indication Dosage of Rabeprazole Sodium delayed-release tablets Treatment Duration Adults Healing of Erosive or Ulcerative Gastroesophageal Reflux Disease (GERD) 20 mg once daily 4 to 8 weeks* Maintenance of Healing of Erosive or Ulcerative GERD 20 mg once daily Controlled studies do not extend beyond 12 months Symptomatic GERD in Adults 20 mg once daily Up to 4 weeks** Healing of Duodenal Ulcers 20 mg once daily after the morning meal Up to 4 weeks*** Helicobacter pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence Rabeprazole sodium delayed-release tablets 20 mg Amoxicillin 1000 mg Clarithromycin 500 mg Take all three medications twice daily with morning and evening meals; it is important that patients comply with the full 7-day regimen [see Clinical Studies ( 14.5 )] 7 days Pathological Hypersecretory Conditions, Including Zollinger-Ellison Syndrome Starting dose 60 mg once daily then adjust to patient needs; some patients require divided doses Dosages of 100 mg once daily and 60 mg twice daily have been administered As long as clinically indicated Some patients with Zollinger-Ellison syndrome have been treated continuously for up to one year Adolescents 12 Years of Age and Older Symptomatic GERD 20 mg once daily Up to 8 weeks Administration Instructions Swallow rabeprazole sodium delayed-release tablets whole. Do not chew, crush, or split tablets. For the treatment of duodenal ulcers take rabeprazole sodium delayed-release tablets after a meal. For Helicobacter pylori eradication take rabeprazole sodium delayed-release tablets with food. For all other indications rabeprazole sodium delayed-release tablets can be taken with or without food. Take a missed dose as soon as possible. If it is almost time for the next dose, skip the missed dose and go back to the normal schedule. Do not take two doses at the same time.

6 ADVERSE REACTIONS Most common adverse reactions in adults (>2%) are pain, pharyngitis, flatulence, infection, and constipation ( 6.1 ). Most common adverse reactions in adolescents (≥2%) are headache, diarrhea, nausea, vomiting, and abdominal pain ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Torrent Pharma Inc. at 1-800-912-9561 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch The following serious adverse reactions are described below and elsewhere in labeling: Acute Tubulointerstitial Nephritis [see Warnings and Precautions ( 5.3 )] Clostridium difficile- Associated Diarrhea [see Warnings and Precautions ( 5.4 )] Bone Fracture [see Warnings and Precautions ( 5.5 )] Cutaneous and Systemic Lupus Erythematosus [ see Warnings and Precautions ( 5.7 ) ] Cyanocobalamin (Vitamin B-12) Deficiency [see Warnings and Precautions ( 5.8 )] Hypomagnesemia and Mineral Metabolism [see Warnings and Precautions ( 5.9 )] Fundic Gland Polyps [see Warnings and Precautions ( 5.11 )] 6.1 Clinical Studies Experience Because clinical trials are conducted under varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adults The data described below reflect exposure to rabeprazole sodium delayed-release tablets in 1,064 adult patients exposed for up to 8 weeks. The studies were primarily placebo- and active-controlled trials in adult patients with Erosive or Ulcerative Gastroesophageal Reflux Disease (GERD), Duodenal Ulcers and Gastric Ulcers. The population had a mean age of 53 years (range 18 to 89 years) and had a ratio of approximately 60% male: 40% female. The racial distribution was 86% Caucasian, 8% African American, 2% Asian, and 5% other. Most patients received either 10 mg, 20 mg or 40 mg per day of rabeprazole sodium delayed-release tablets. An analysis of adverse reactions appearing in ≥2% of patients treated with rabeprazole sodium delayed-release tablets (n=1,064) and with a greater frequency than placebo (n=89) in controlled North American and European acute treatment trials, revealed the following adverse reactions: pain (3% vs. 2%), pharyngitis (3% vs. 2%), pharyngitis (3% vs. 2%), flatulence (3% vs. 1%), infection (2% vs. 1%), and constipation (2% vs. 1%). Three long-term maintenance studies consisted of a total of 740 adult patients; at least 54% of adult patients were exposed to rabeprazole sodium delayed-release tablets for 6 months and at least 33% were exposed for 12 months. Of the 740 adult patients, 247 (33%) and 241 (33%) patients received 10 mg and 20 mg of rabeprazole sodium delayed-release tablets, respectively, while 169 (23%) patients received placebo and 83 (11%) received omeprazole. The safety profile of rabeprazole in the maintenance studies in adults was consistent with what was observed in the acute studies. Less common adverse reactions seen in controlled clinical trials (<2% of patients treated with rabeprazole sodium delayed-release tablets and greater than placebo) and for which there is a possibility of a causal relationship to rabeprazole, include the following: headache, abdominal pain, diarrhea, dry mouth, dizziness, peripheral edema, hepatic enzyme increase, hepatitis, hepatic encephalopathy, myalgia, and arthralgia. Combination Treatment with Amoxicillin and Clarithromycin: In clinical trials using combination therapy with rabeprazole plus amoxicillin and clarithromycin (RAC), no adverse reactions unique to this drug combination were observed. In the U.S. multicenter study, the most frequently reported drug related adverse reactions for patients who received RAC therapy for 7 or 10 days were diarrhea (8% and 7%) and taste perversion (6% and 10%), respectively. No clinically significant laboratory abnormalities particular to the drug combinations were observed. For more information on adverse reactions or laboratory changes with amoxicillin or clarithromycin, refer to their respective prescribing information, Adverse Reactions section. Pediatrics In a multicenter, open-label study of adolescent patients 12 to 16 years of age with a clinical diagnosis of symptomatic GERD or endoscopically proven GERD, the adverse event profile was similar to that of adults. The adverse reactions reported without regard to relationship to rabeprazole sodium delayed-release tablets that occurred in ≥2% of 111 patients were headache (9.9%), diarrhea (4.5%), nausea (4.5%), vomiting (3.6%), and abdominal pain (3.6%). The related reported adverse reactions that occurred in ≥2% of patients were headache (5.4%) and nausea (1.8%). There were no adverse reactions reported in this study that were not previously observed in adults. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of rabeprazole. Because these reactions are reported voluntarily from a population of uncertain size, it is not alway

7 DRUG INTERACTIONS See full prescribing information for a list of clinically important drug interactions ( 7 ). Table 2 includes drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with rabeprazole sodium delayed-release tablets and instructions for preventing or managing them. Consult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs. Table 2: Clinically Relevant Interactions Affecting Drugs Co-Administered with Rabeprazole Sodium Delayed-Release Tablets and Interactions with Diagnostics Antiretrovirals Clinical Impact: The effect of PPI on antiretroviral drugs is variable. The clinical importance and the mechanisms behind these interactions are not always known. • Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir, and nelfinavir) when used concomitantly with rabeprazole may reduce antiviral effect and promote the development of drug resistance. • Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with rabeprazole may increase toxicity . • There are other antiretroviral drugs which do not result in clinically relevant interactions with rabeprazole. Intervention: Rilpivirine-containing products : Concomitant use with rabeprazole sodium delayed-release tablets is contraindicated [see Contraindications ( 4 )] . See prescribing information. Atazanavir : See prescribing information for atazanavir for dosing information. Nelfinavir : Avoid concomitant use with rabeprazole sodium delayed-release tablets. See prescribing information for nelfinavir. Saquinavir : See the prescribing information for saquinavir and monitor for potential saquinavir toxicities. Other antiretrovirals : See prescribing information. Warfarin Clinical Impact: Increased INR and prothrombin time in patients receiving PPIs, including rabeprazole, and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death [see Warnings and Precautions ( 5.2 )]. Intervention: Monitor INR and prothrombin time. Dose adjustment of warfarin may be needed to maintain target INR range. See prescribing information for warfarin. Methotrexate Clinical Impact: Concomitant use of rabeprazole with methotrexate (primarily at high dose) may elevate and prolong serum levels of methotrexate and/or its metabolite hydroxymethotrexate, possibly leading to methotrexate toxicities. No formal drug interaction studies of methotrexate with PPIs have been conducted [see Warnings and Precautions ( 5.9 )]. Intervention: A temporary withdrawal of rabeprazole sodium delayed-release tablets may be considered in some patients receiving high dose methotrexate administration. Digoxin Clinical Impact: Potential for increased exposure of digoxin [see Clinical Pharmacology ( 12.3 )]. Intervention: Monitor digoxin concentrations. Dose adjustment of digoxin may be needed to maintain therapeutic drug concentrations. See prescribing information for digoxin. Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole, itraconazole) Clinical Impact: Rabeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity. Intervention: Mycophenolate mofetil (MMF): Co-administration of PPIs in healthy subjects and in transplant patients receiving MMF has been reported to reduce the exposure to the active metabolite, mycophenolic acid (MPA), possibly due to a decrease in MMF solubility at an increased gastric pH. The clinical relevance of reduced MPA exposure on organ rejection has not been established in transplant patients receiving rabeprazole sodium delayed-release tablets and MMF. Use rabeprazole sodium delayed-release tablets with caution in transplant patients receiving MMF. See the prescribing information for other drugs dependent on gastric pH for absorption. Combination Therapy with Clarithromycin and Amoxicillin Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated. Amoxicillin also has drug interactions. Intervention: See Contraindications and Warnings and Precautions in prescribing information for clarithromycin. See Drug Interactions in prescribing information for amoxicillin. Tacrolimus Clinical Impact: Potentially increased exposure of tacrolimus, especially in transplant patients who are intermediate or poor metabolizers of CYP2C19. Intervention: Monitor tacrolimus whole blood trough concentrations. Dose adjustment of tacrolimus may be needed to maintain therapeutic drug concentrations. See prescribing information for tacrolimus. Interactions with Investigations of Neuroendocrine Tumors Clinical Impact: Serum chromogranin A (CgA) levels increase secondary to PPI-induced decreases in gastric acidity. The increased CgA level may c