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General Information
Duexis is a proprietary formulation of the non-steroidal anti-inflammatory drug (NSAID) ibuprofen, combined with the potent H2 receptor antagonist famotidine, in a single pill. It was formulated to provide pain relief while reducing stomach acidity during the peak time of risk for ulceration.
Duexis is specifically indicated for the relief of signs and symptoms of rheumatoid arthritis and osteoarthritis and to decrease the risk of developing upper gastrointestinal ulcers in patients who are taking ibuprofen for those indications.
Duexis is supplied as a tablet for oral administration. The recommended dose is 800 mg/26.6 mg ((ibuprofen/famotidine) as a single tablet administered orally three times per day. The tablets should be swallowed whole, and should not be cut to supply a lower dose.
Mechanism of Action
Duexis is a proprietary formulation of the non-steroidal anti-inflammatory drug (NSAID) ibuprofen, combined with the potent H2 receptor antagonist famotidine, in a single pill. It was formulated to provide pain relief while reducing stomach acidity during the peak time of risk for ulceration. Ibuprofen possesses analgesic and antipyretic activities. Its mode of action, like that of other NSAIDs, is not completely understood, but may be related to prostaglandin synthetase inhibition. Famotidine is a competitive inhibitor of histamine H2-receptors. The primary clinically important pharmacologic activity of famotidine is inhibition of gastric secretion.
Side Effects
Adverse events associated with the use of Duexis may include, but are not limited to, the following:
- nausea
- diarrhea
- constipation
- upper abdominal pain
- headache
Clinical Trial Results
The FDA approval of Duexis was based on two multicenter, double-blind, active-controlled, randomized, 24-week studies (Studies 301 and 303). A total of 1533 subjects were enrolled; all subjects were expected to require daily administration of an NSAID for at least the coming six months for conditions such as the following: osteoarthritis, rheumatoid arthritis, chronic low back pain, chronic regional pain syndrome, and chronic soft tissue pain. The subjects received either Duexis or ibuprofen (800 mg) three times a day for 24 consecutive weeks. In both trials, Duexis was associated with a statistically significantly reduction in the risk of developing upper gastrointestinal ulcers compared to taking ibuprofen only during the six month study period. Two analyses for each endpoint were conducted. In analysis one, patients who terminated early, without an endoscopic evaluation within 14 days of their last dose of study drug, were classified as not having an ulcer. In analysis two, those patients were classified as having an ulcer. Efficacy was based on the overall incidence rates of subjects who developed at least one upper gastrointestinal ulcer (primary endpoint) or gastric ulcer (secondary endpoint). The results are as follows:
Study 301
- Primary endpoint: Analysis 1: Duexis- 10.5% vs. Ibuprofen - 20.0% (p0.002); Analysis 2: Duexis- 22.9% vs. Ibuprofen 32.1% (p0.020).
- Secondary endpoint: Analysis 1: Duexis- 9.7% vs. Ibuprofen - 17.9% (0.005); Analysis 2: Duexis- 22.4% vs. Ibuprofen 30.0% (p0.052).
Study 303
- Primary endpoint: Analysis 1: Duexis- 8.7% vs. Ibuprofen - 17.6% (p0.0004); Analysis 2: Duexis- 17.4% vs. Ibuprofen- 31.0% (p<0.0001).
- Secondary endpoint: Analysis 1: Duexis- 10.1% vs. Ibuprofen - 21.3% (p<0.0001); Analysis 2: Duexis- 18.6% vs. Ibuprofen 34.3% (<0.0001).