Is Cymbalta Behind the New FDA Push to Ban Darvocet?

A panel of government medical experts this week asked the Food and Drug Administration to take the pain medicines Darvon and Darvocet off the market. Darvon, now primarily marketed as Darvocet, is one of the top 25 most commonly prescribed medicines. According to Atlanta Jounal Constitution, the group Public Citizen is behind the effort to ban these drugs.

Darvocet is a combination medicine that includes Darvon plus Acetaminophen. Acetaminophen is sold by the brand name Tylenol. Darvocet frequently is prescribed to help manage fibromyalgia and arthritis and other pain.

Eli Lilly & Co., a major pharmaceutical corporation, patented the active ingredient in Darvon in December 1955. Darvon was approved by the FDA and was first marketed in 1957. Five years later, in 1962, Lilly patented an ingredient related to that in Darvon. Based on that new patent, Lilly began marketing a drug, Darvon-N, in 1971. According to a lawsuit, Lilly v. IRS, by that time, Darvon and related drugs had earned Lilly over $30.2 million in pre-tax net income.

Public Citizen, the consumer group behind this week's recommendation to ban Darvocet, made its first attempt to have the drug withdrawn in 1978. Public Citizen filed a petition for withdrawal of the drug to the FDA in 2006. In 2008, Public Citizen filed a lawsuit against the FDA for failure to act on its petition to withdraw the drug. In January 2009, Public Citizen again petitioned the FDA to ban Darvocet. This time, after a day of hearings, the FDA panel agreed with Public Citizen and recommended Darvocet be removed from the market.

According to the Wall Street Journal, the panel's members "voted 14-12 that [Darvocet's] benefits didn't outweigh its risks." Although the panel called for banning Darvocet in the United States, the Food and Drug Administration makes the final decision. The Wall Street Journal explains that the FDA "usually adopts panel recommendations but not always, especially when the vote is so close."

Darvocet, once protected under a lucrative patent held by Eli Lilly & Co., has been off patent for many years. Generic Darvocet is manufactured by several companies. According to the Atlanta Journal Constitution, Davocet is marketed by Xanodyne Pharmaceuticals and Qualitest/Vintage Phamaceuticals.

Even though Darvon is over 50 years old, market watchers no doubt take note that this off-patent drug continues to be widely prescribed. Over 20 million prescriptions for Darvocet and related drugs were written in 2006 and 2007.

In 2004, Eli Lilly & Co. launched a drug, Cymbalta, targeted to the same market segment as Darvocet. Like Darvocet, Cymbalta is used for fibromyalgia and diabetic nerve pain. It also is prescribed to treat depression and generalized anxiety disorder. As a new drug, Cymbalta likely will be under patent for several years. Patents prohibit generic versions of the drug. This can make a patented drug very profitable.

Public Citizen challenged Darvon's safety and effectiveness profile for more than three decades. In 2009, Public Citizen finally persuaded a FDA review panel to recommend banning Darvon and related drugs.

The key to this change in direction on the part of the FDA may lie in the panel's standard of review. The standard was "whether the benefits [of Darvon] outweighed the risks." One aspect of evaluating how beneficial a drug is is determining what alternative drugs are available. Now that Cymbalta, and other new drugs such as Lyrica, are on the market, they may be viewed as displacing the older, cheaper stand-by, Darvocet.

Public Citizen relied on data from the Drug Abuse Warning Network regarding drug-related deaths and accidental deaths. The FDA also considered reports of suicides and heart attacks. Public Citizen said the FDA's own data demonstrated that Davocet was an ineffective analgesic. According to You Have a Lawyer, "Public Citizen indicates [Darvocet] is no more effective than common drugs like ibuprofen or acetaminophen for many kinds of pain."

If one measure of efficacy of a drug is the number of people who depend on it for pain relief, the 50-plus-year old Darvon, and related drugs, are still going strong. Carol and Richard Eustice, writing in Arthritis Blog, explain that people who find Darvocet works for their medical situation "depend on this drug so that they can function and have quality of life."

The Food and Drug Administration will make the final decision on whether to withdraw Darvocet from the market. The close vote of the review panel, 14-12 in support of banning this widely prescribed, older drug, makes it a close call for the FDA, even if newer, patented drugs are now available.

Sources:

"FDA Panel: Withdraw Painkiller," Atlanta Journal Constitution.

"Eli Lilly and Company v. Commissioner of the Internal Revenue Service," United States Court of Appeals for the Seventh Circuit.

"FDA Panel to Consider Fate of Pain Pills Darvon," CNN.

"Darvon and Darvocet Lawsuit filed against FDA by Public Cititzen," You Have a Lawyer.

Jennifer Corbett Dooren and Alicia Mundy, "Panel Urges Darvon Ban," Wall Street Journal Online.

"Cymbalta approved for diabetic peripheral neuropathy pain," News-Medical.

Cymbalta Official Site.

"Solving the Drug Patent Problem," Forbes.

Carol and Richard Eustice, "Ban on Darvon, Darvocet, and Propoxyphene Sought By Public Citizen," Arthritis About.