There have been 8 adverse events with the patch, all involving ingestion, Navartis spokesperson, Julie Masow, told the Philadelphia Inquirer on June 21, 2006.
The patches were sold over the counter at pharmacies and retail stores and Novartis said it has sold more than 50 million vapor patches since they came on the market in 2000.
The Swiss drug maker warned consumers to stop using the patch immediately and said they should either be discarded or returned to the place of purchase for a full refund.
Ingesting camphor or eucalyptus oils can cause a burning sensation in the mouth, nausea, headache, vomiting and seizure. Other complaints received by the company associated with the patch include reports of blistering, bruising, scarring, hyperactivity and depigmentation.
Whether the patch will remain off the market is not known. According to a June 21, 2006, Press Release by the LecTec Corporation, in January 2004, LecTec entered into a Supply and License Agreement with Novartis under which LecTec licensed certain of its patents to Novartis for the production of vapor patches.
The royalties received by LecTec under this agreement represented substantially all of the firm's revenues in fiscal 2005, as well as the first quarter of fiscal 2006. The specific patch that caused the seizure was not manufactured by LecTec, according to Novaris quoted in the press release.
Over roughly the past 25 years, patch medications have become a booming business for Big Pharma. More than 30 different types of patches have been used by 12 million people worldwide for conditions ranging from birth control to heart disease to chronic pain to bladder control. The first antidepressant patch was approved by the FDA this month.
In 2004, patch sales totaled about $3.4 billion, according to the medical market research firm Greystone Associates.
All medication releasing patches work the same, according to Bozena Michniak, who studies transdermal patch delivery systems at the Center for Biomaterials at Rutgers University. The medication seeps through the skin into the bloodstream, and the increased blood flow causes the body to absorb the drug.
As more versions of the medication patches are introduced on the market, medical experts say that many of them are unsafe. Multiple studies have shown that heat has a dangerous effect on the patches, whether from a high fever, exercise or a hot tub. Heat increases the absorption rate of the medication and sometimes with fatal results.
As far back as 1986, a study found that just 20 minutes of bicycling with a nitroglycerin patch increased concentration of the drug two to threefold. Similar results were found after 30 minutes in a sauna, according to an article in Philly.com on March 5, 2006.
But yet there was no public warnings added to the Fentanyl pain patch until 36-year-old Kurt Hophan died in Pennsylvania on March 4, 1994.
Fentanyl, a schedule II narcotic analgesic, is roughly 50-80 times more potent than morphine and is used to manage both pain during surgery and for persons with chronic moderate to severe pain who already are physically tolerant to opiates, according to the US Center for Substance Abuse Treatment.