Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely prescribed for reduction of pain and inflammation, particularly in the setting of rheumatologic disorders. While effective, they are associated with risks, including nephrotoxicity, gastrointestinal inflammation, peptic ulcer disease, and worsened cardiovascular outcomes. After development of cyclo-oxygenase 2 inhibitors to minimize gastrointestinal complications, early use revealed increased cardiovascular event rate risk, and retrospective analysis of traditional NSAIDs revealed similar concerns, with the exception of naproxen. PN400 is a fixed-dose combination formulation designed to provide sequential delivery of a nonenteric-coated, immediate-release esomeprazole 20 mg mantle followed by an enteric-coated naproxen 500 mg core. This review summarizes the pharmacokinetics, benefits, safety, and tolerability of PN400. Phase I trials demonstrated pharmacokinetics consistent with its formulation, and at different esomeprazole combination doses, PN400 containing esomeprazole 20 mg was the lowest dose that still resulted in substantial sustained increases of gastric pH > 4. In two Phase III trials (Study 301 and Study 302), PN400 resulted in a significant reduction in gastric ulcers relative to enteric-coated naproxen (4.1% to 23.1% in Study 301, 7.1% to 24.3% in Study 302). Discontinuation due to NSAID-associated upper gastrointestinal adverse events or duodenal ulcers was significantly less in PN400 patients (3.2% to 12%, P < 0.001, in Study 301; 4.8% to 11.9%, P = 0.009, in Study 302). Two subjective patient indices were utilized to assess tolerability, ie, the Severity of Dyspepsia Assessment (SODA) and Overall Treatment Evaluation of Dyspepsia (OTE-DP). Patients with PN400 had significantly better upper gastrointestinal tolerability compared with those treated with enteric-coated naproxen in terms of SODA scores, proportion of heartburn-free patients, and OTE-DP response. While no formal recommendations are available at this time for use of this new combination medication, it will likely become an important treatment option with application for many patients.
Keywords: combination; esomeprazole; gastrointestinal tolerability; naproxen.