Monday, August 13, 2007

Problems with Skin Patches

I have always been a big fan of medication patches from the begining for medication adherence. I remember first seeing "the patch" for smoking sensation and am glad that they are able to adapt this technology for Alzheimer's and Parkinson's. Although I do remember my father smoking and chewing Nicorette while using the patch, and getting incredibly sick.

I had heard about problems with the contraceptive patch, but had never heard of a narcotic patch. I can see how these problems can occur, especially for older patients who put a patch on Monday, then forget on Wednesday and put another one on. Although I would think they would solve this problem with packaging.

And discarded patches seem to be a problem as well. Here's an article I found from the Toronto Star from 8/7/07. It only discusses Canadian problems, but I'm sure they are applicable in the US.

Skin Patches Have Their Downside by Nancy J. White.

Morag Dickie liked the convenience. She could just slap the nitroglycerin patch onto her body in the morning and not worry about popping pills.

"I could feel a consistent flow of energy," says Toronto resident Dickie, 55, a heart patient.

That's the idea behind a skin patch – an easy-to-use method with smooth, controlled drug release, not the peaks and valleys of ingested medicine. In the U.S. last month, the Food and Drug Administration approved the first skin patch to treat Alzheimer's disease. In May, it gave the green light to a drug patch for Parkinson's disease. Last year, medicinal patches were approved Attention Deficit Hyperactivity Disorder and depression.

Researchers are developing an insulin patch for diabetics.

But it's also a system that can present problems from the occasional skin irritation – the reason Dickie, who has sensitive skin, had to eventually give up her patch – to unintended poisonings. Three people in this country have died from use of the narcotic fentanyl patch, according to the Institute for Safe Medication Practices Canada (ISMPC).

In June, a federal jury in the U.S. awarded $5.5 million to the father of a 28-year-old man who died in 2003 while wearing a fentanyl patch for chronic hip pain after a car accident.

In Canada, prescription patches are approved for a handful of uses, including contraception and hormone replacement therapy, pain relief, smoking cessation, prevention of motion sickness and control of angina.

As for new ones, Health Canada does not disclose drugs it is reviewing, according to a spokesman. The patch to treat the dementia of Alzheimer's has been submitted to Health Canada and the manufacturer hopes for approval next year, says Jason Jacobs, a spokesman for Novartis Pharmaceuticals Canada. That patch delivers the drug Exelon or rivastigmine, which is currently sold in Canada for oral use.

Patches provide a smoother delivery of drugs than tablets, which send medication for absorption to the intestine, and may lessen the potential for side effects by avoiding a high peak.

They are longer-acting, some up to a week. "There's better compliance when the patient doesn't have to worry about taking a medicine three or four times a day," says Bill Wilson, pharmacy director at Mount Sinai Hospital.

Patients may, however, forget they're wearing a patch, especially since some are clear. "We've had reports of more than one patch of the same drug put on a person," says Sylvia Hyland, vice president of the non-profit group ISMPC.

Youngsters have been poisoned by chewing ondiscarded patches or putting them on. "Children are fascinated by stickers and bandages," says Hyland. "A thrown-away patch still has some drug in it."

The ISMP has had reports from emergency room staff concerned by unlabelled patches. And the most dangerous are the patches delivering fentanyl, a narcotic. "They need to be prescribed appropriately for chronic severe pain, not acute pain," explains Hyland. "Physicians need to be very knowledgeable about the patch."

Two of the Canadian deaths from the fentanyl patch were adolescents. The deaths occurred in 2004. It's supposed to be only for adults, says Hyland.

The birth-control patch, EVRA, has also raised concerns after a study indicated women using it in the U.S. had an increased risk of blood clots in the legs and lungs than women on an oral contraceptive. Another study, however, showed no difference in the risk.

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