may be allergic to omeprazole, esomeprazole, and pantoprazole, but not to lansoprazole and rabeprazole. This is thought to be due to the structural similarities between omeprazole, esomeprazole, and pantoprazole, contrasted with lansoprazole and rabeprazole. Pattern B is the opposite, reflecting people that are allergic to lansoprazole and rabeprazole, but not to omeprazole, esomeprazole, and pantoprazole. Pattern C, in the context of rabeprazole, would reflect a person that is allergic to only rabeprazole, but not to other PPIs (omeprazole, esomeprazole, pantoprazole, and lansoprazole). Rilpivirine Rilpivirine, a non-nucleoside reverse transcriptase inhibitor used in the treatment of HIV, is contraindicated with all PPIs because of their acid-suppressing effect. PPIs suppress acid, thereby raising the pH of (alkalizing) the stomach's contents. Rilpivirine is best absorbed under acidic conditions. Therefore, rabeprazole would be expected to decrease the absorption of rilpivirine, decrease the concentration of rilpivirine in the blood, and possibly lead to therapeutic failure and resistance to the medication/class. Adverse effects In general, rabeprazole is fairly well tolerated, even up to five years after clinical trial follow-up. The side effect profile is similar to that of omeprazole. The most common side effects include headache, nausea, and diarrhea. Rare side effects include rashes, flu-like symptoms, and infections (including by the gastrointestinal pathogen Clostridium difficile). Rare instances of rabeprazole-induced liver injury (also known as hepatotoxicity) have been reported. Characteristic proton-pump inhibitor hepatoxicity usually occurs within the first four weeks of starting the medication. Rabeprazole is associated with elevated serum gastrin levels, which are thought to be dependent upon the degree of CYP2C19 metabolism the drug undergoes. In comparison, rabeprazole is not as significantly metabolized by this enzyme compared to other medications in the same class, like omeprazole. Elevated serum gastrin may be associated with gastric cancer. Acid suppression via rabeprazole can decrease the absorption of vitamin B12 and magnesium, leading to deficiency. Very serious side effects have been reported in people taking rabeprazole, but these effects have not been "correlated directly" with the use of rabeprazole. These include Stevens–Johnson syndrome, serious hematological abnormalities, coma, and death. Other possible side effects, common to other PPIs medications in the same class, include bone fractures due to osteoporosis and serious infections with Clostridium difficile. Overdose No signs and symptoms have been reported in overdoses of rabeprazole up to 80 mg, but case examples are limited. Notably, rabeprazole has been used in higher doses for the treatment of hypersecretory conditions like