Oxaprozin
(Molecule of the Month February 2000)
Oxaprozin
Oxaprozin is used for acute and long-term use in the management of the signs and symptoms of steo-arthritis and rheumatoid arthritis. Oxaprozin (Daypro®) is a nonsteroidal anti-inflammatory drug (NSAID) that also has analgesic and antipyretic properties. Oxaprozin is readily absorbed following oral dosing with peak plasma concentrations occurring at 3 to 5 hours, and an elimination half-life of 42 to 50 hours. Because of the long half-life, it takes several days of dosing to reach steady state plasma levels, and several days before the full effects of therapy are reached. Oxaprozin is essentially totally bound to plasma protein (albumin).
Rheumatoid Arthritis
In a study Daypro was evaluated for managing the signs and symptoms of Rheumatoid Arthritis in placebo and active controlled clinical trials in a total of 646 patients. Daypro was given in single or divided daily doses of 600 to 1 800 mg/day and was found to be comparable to 2600 to 3900mg/day of aspirin. At these doses there was a trend (over all trials) for Oxaprozin to be more effective and cause fewer gastrointestinal side effects than Disprin.
Daypro was given as a once-a-day dose of 1 200mg in most of the clinical trials, but larger doses (up to 26mg/kg or 1800mg/day) were used in selected patients. In some patients, Daypro may be better tolerated in divided doses. Due to its long half-life, several days of Daypro therapy were needed for the drug to reach its full effect.
Precautions
on usage
Oxaprozin or Daypro can cause stomach irritation including ulcer perforation. It prolongs bleeding times and has been associated with fulminating hepatitis. People with sensitive stomachs and/or ulcer disease may not be able to tolerate Oxaprozin or Daypro, and some people may be allergic to the drug. Because it has been associated with liver problems, people with liver disease should use Oxaprozin or Daypro only under medical supervision.
Oxaprozin or Daypro prolongs bleeding times and thus can interact with anticoagulants. It has been reported to interact with benzodiazepines to precipitate panic disorders.
For more information on Daypro, at: http://www.daypro.com/
by Dr Karl Harrison - Department of Chemistry - University of Oxford
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