Patients are frequently administered the drugs in intensive care as a protective measure against ulcers, but this use is also associated with a 30% increase in occurrence of pneumonia.Long-term use of proton pump inhibitors in patients treated for Helicobacter pylori has been shown to dramatically increase the risk of gastric cancer.Acute tubulointerstitial nephritis is a possible adverse reaction when using proton pump inhibitors. Interactions
Esomeprazole is a competitive inhibitor of the enzyme CYP2C19, and may therefore interact with drugs that depend on it for metabolism, such as diazepam and warfarin; the concentrations of these drugs may increase if they are used concomitantly with esomeprazole. Conversely, clopidogrel (Plavix) is an inactive prodrug that partially depends on CYP2C19 for conversion to its active form; inhibition of CYP2C19 blocks the activation of clopidogrel, thus reducing its effects.Drugs that depend on stomach pH for absorption may interact with omeprazole; drugs that depend on an acidic environment (such as ketoconazole or atazanavir) will be poorly absorbed, whereas drugs that are broken down in acidic environments (such as erythromycin) will be absorbed to a greater extent than normal. Pharmacokinetics
Single 20 to 40 mg oral doses generally give rise to peak plasma esomeprazole concentrations of 0.5-1.0 mg/L within 1–4 hours, but after several days of once-daily administration, these levels may increase by about 50%. A 30-minute intravenous infusion of a similar dose usually produces peak plasma levels on the order of 1–3 mg/L. The drug is rapidly cleared from the body, largely by urinary excretion of pharmacologically inactive metabolites such as 5-hydroxymethylesomeprazole and 5-carboxyesomeprazole.
Esomeprazole and its metabolites are analytically indistinguishable from omeprazole and the corresponding omeprazole metabolites unless chiral techniques are employed. Dosage forms
Esomeprazole is available as delayed-release capsules in the United States or as delayed-release tablets in Australia, the United Kingdom, and Canada (containing esomeprazole magnesium) in strengths of 20 and 40 mg, as delayed-release capsules in the United States (containing esomeprazole strontium) in a 49.3 mg strength (delivering the equivalent of 40 mg of esomeprazole, and as esomeprazole sodium for intravenous injection/infusion. Oral esomeprazole preparations are enteric-coated, due to the rapid degradation of the drug in the acidic conditions of the stomach. This is achieved by formulating capsules using the multiple-unit pellet system. The combination naproxen/esomeprazole magnesium (brand name Vimovo) is used for the prevention of gastric ulcers associated with chronic NSAID therapy. Vimovo is available in two dosage strengths: 500/20 mg and 375/20 mg. Clinical trials of naproxen/esomeprazole demonstrated an incidence of GI ulcer in 24% of patients on naproxen (alone) versus 7% on naproxen/esomeprazole. The FDA has added warnings to the label for Vimovo concerning acute interstitial nephritis and risk of kidney problems in some patients. Multiple-unit pellet system
Esomeprazole capsules, as well as Losec/Prilosec tablets, are formulated as a "multiple-unit pellet system" (MUPS). Essentially, the capsule consists of extremely small enteric-coated granules (pellets) of the esomeprazole formulation inside an outer shell. When the capsule is immersed in an aqueous solution, as happens when the capsule reaches the stomach, water enters the capsule by osmosis.