In the United States, the Food and Drug Administration (FDA) approved it as an over-the-counter (OTC) drug in 1994. OTC preparations of naproxen in the U.S. are mainly marketed by Bayer HealthCare under the brand name Aleve and generic store brand formulations in 220 mg tablets. In Australia, packets of 275 mg tablets of naproxen sodium are Schedule 2 pharmacy medicines, with a maximum daily dose of five tablets or 1375 mg. In the United Kingdom, 250 mg tablets of naproxen were approved for OTC sale under the brand name Feminax Ultra in 2008, for the treatment of primary dysmenorrhoea in women aged 15 to 50. In the Netherlands, 220 mg and 275 mg tablets are available OTC in drugstores, 550 mg is OTC only at pharmacies. Aleve became available over the counter in some provinces in Canada on 14 July 2009, but not British Columbia, Quebec or Newfoundland and Labrador; it subsequently became available OTC in British Columbia in January 2010. Research
Naproxen may have antiviral activity against influenza. In laboratory research, it blocks the RNA-binding groove of the nucleoprotein of the virus, preventing formation of the ribonucleoprotein complex—thus taking the viral nucleoproteins out of circulation. Veterinary use
Horses
Naproxen is given by mouth to horses at a dose of 10 mg/kg, and has shown to have a wide safety margin (no toxicity when given at three times the recommended dose for 42 days).
It is more effective for myositis than the commonly used NSAID phenylbutazone, and has shown especially good results for treatment of equine exertional rhabdomyolysis, a disease of muscle breakdown; it is less commonly used for musculoskeletal disease. References
External links

"Naproxen". Drug Information Portal. U.S. National Library of Medicine. "Naproxen sodium". Drug Information Portal. U.S. National Library of Medicine.