Sunday, December 23, 2007

Patchwork

This is the dumbest thing ever.

Fentanyl is an opioid analgesic, like morphine or codeine. Unlike everyone's favorite analgesics, Tylenol #3 and Vicodin, fentanyl is most commonly administered via a transdermal patch that is worn on the skin. Oral forms are available, but considerably less common (notably orally-disintegrating tablets and even a narcotic sucker). Fentanyl is very potent, and must be used in small doses--25 micrograms (or 0.025 mg) of fentanyl per hour over a 24-hour period is recommended for patients taking between 60 and 134 milligrams of oral morphine per day. Fentanyl should not even be initiated in patients taking less than this--for comparison's sake, 60 mg of morphine is equivalent to 30 mg of oxycodone. Your standard Percocet tablet has 5 mg of oxycodone per tablet.

I may be belaboring the point. In any case, fentanyl is potent stuff. It takes very little fentanyl to match an equivalent dose of some other opioid painkiller.

Prescribing fentanyl for patients with anything less than chronic pain due to cancer or long-term injuries is irresponsible. The package insert itself says that using fentanyl patches for short-term pain is a mistake. Physicians prescribing the patches for patients with headaches are only part of the problem; there are no statistics available, as far as I can tell, but I'm willing to bet that much of the problem not misprescribing of fentanyl. The problem is misuse. Not in the sense of drug abuse, but rather in the sense of improper administration of the patches. Heating pads are a popular means of relieving chronic pain. But putting a heating pad over a fentanyl patch will dramatically increase the rate of transfer from the patch into the patient's bloodstream, potentially resulting in death when the patient's central nervous system stops triggering the breathing reflex. Patients who slap on a patch and then get into a hot tub may not get out.

An interesting issue is that transdermal patches must contain much more active ingredient than is to be delivered to the patient because the rate of transfer from the patch to the bloodstream is dependent on the difference between drug in the skin and drug in the patch. In short, a patch that only delivers 0.025 mg per hour may have to contain 3 mg of total drug to keep the flow moving. This means that a "used" patch still contains a lot of drug, and improper disposal of the patch can result in children or animals getting ahold of a lot of "leftover" fentanyl--easily fatal, should the patch be chewed or torn.

These deaths are so preventable it's ridiculous. A little patient education about the proper use and disposal of fentanyl would have saved nearly everyone involved. This is the task set before pharmacists. This is the value of proper patient counseling. Like all drugs, fentanyl has risks. But the risks can be minimized if patients are properly informed. Counseling for such drugs should be legally mandated--and furthermore, drugstores should be required to give pharmacists the time and staffing to perform the task adequately. These deaths aren't the fault of pharma. They're due to ignorance and irresponsibility. Pharmacists need to educate their patients--and patients need to pay attention instead of quacking away on cellphones while they sign the pick-up log for their fentanyl patches.

If in two weeks I have to read another article about fentanyl patches for the fourth month in a row I'm going to go crazy.

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