November 9, 2005

A generic gout medication could double supplies of Roche's flu drug Tamiflu by preventing it from being excreted in urine, according to a 2002 study by Roche.
Tamiflu (oseltamivir phosphate) has been shown effective in easing symptoms of a bird flu strain that has killed more than 60 people in Asia.

The study, published in the January 2002 issue of Drug Metabolism and Disposition, found that taking probenecid along with Tamiflu doubles the amount of time that Tamiflu stays in the body and doubles the concentration of Tamiflu in the blood, according to an article published Tuesday in the journal Nature.

Probenecid prevents the kidneys from secreting various drugs and thereby prevents them from being excreted in urine. The drug was used during World War II to extend scarce penicillin supplies, and is still used today in patients with gonorrhea and syphilis to maintain high levels of antibiotics in those patients, according to Nature.

Making each dose of Tamiflu twice as effective would help relieve global demand for the drug, which skyrocketed after the World Health Organization told governments to stockpile enough Tamiflu for at least 25 percent of their populations. To boost Tamiflu production, Roche — in a deal announced by Charles Schumer (D-N.Y.) and Lindsey Graham (R-S.C.) late last month — agreed to discuss potential sublicensing agreements with generic drugmakers.

President Bush this week unveiled a $7.1 billion plan to prepare the U.S. against a flu pandemic, including $1 billion to purchase antiviral drugs such as Tamiflu and GlaxoSmithKline's Relenza (zanamivir).

The Roche study can be found at http://dmd.aspetjournals.org/cgi/content/abstract/30/1/13.