The following serious adverse reactions are described below and elsewhere in labeling: Acute Interstitial Nephritis [see Warnings and Precautions (5.3) ] Cyanocobalamin (vitamin B-12) Deficiency [see Warnings and Precautions (5.4) ] Clostridium difficile Associated Diarrhea [see Warnings and Precautions (5.5) ] Bone Fracture [see Warnings and Precautions (5.6) ] Hypomagnesemia [see Warnings and Precautions (5.7) ] 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 Eisai Inc. at 1-888-274-2378 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 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 ACIPHEX delayed-release tablets in 1064 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 18-89 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 ACIPHEX delayed-release tablets. An analysis of adverse reactions appearing in ≥2% of patients treated with ACIPHEX delayed-release tablets (n=1064) 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. 1%), 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 ACIPHEX 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 ACIPHEX 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 ACIPHEX 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. Pediatric s 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 ACIPHEX 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 always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: sudden death; coma, hyperammonemia; jaundice; rhabdomyolysis; disorientation and delirium; anaphylaxis; angioedema; bullous and other drug eruptions of the skin; severe dermatologic reactions, including toxic epidermal necrolysis (some fatal), Stevens-Johnson syndrome, and erythema multiforme; interstitial pneumonia; interstitial nephritis; TSH elevations; bone fractures; hypomagnesemia and Clostridium diffic i le -associated diarrhea. In addition, agranulocytosis, hemolytic anemia, leukopenia, pancytopenia, and thrombocytopenia have been reported. Increases in prothrombin time/INR in patients treated with concomitant warfarin have been reported.