FDA Patient Safety News: Show #38, April 2005

New Treatment for Age-Related Macular Degeneration

FDA recently approved a new drug to slow vision loss in people with the neovascular or “wet” form of age-related macular degeneration. Although the "wet" form accounts for only 10% of all cases, it's often more visually debilitating than the "dry" form. The drug is called Macugen (pegaptanib sodium injection), and it is distributed by Eyetech Pharmaceuticals and Pfizer Inc.

Macugen provides clinicians and patients with another alternative to the traditional laser treatment. It works by inhibiting the growth of abnormal retinal blood vessels that characterize the “wet” form of macular degeneration. It's injected into the affected eye once every six weeks.

The safety and efficacy of Macugen was studied in two clinical trials of patients with wet AMD. In both trials, patients who were treated with the drug lost vision at a slower rate than the untreated patients. Serious adverse events related to the injection procedure included infections, retinal detachment, and traumatic cataracts. Patients should be monitored for signs of inflammation and infection for a week following injection. Other frequently reported adverse events were eye irritation, eye pain, increased intraocular pressure, subconjunctival hemorrhage, and blurred vision.

Additional Information:

FDA Press Release - FDA Approves New Drug Treatment for Age-Related Macular Degeneration.
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2004/ucm108385.htm


Public Health Advisory on Viramune (nevirapine) for HIV

FDA has issued a Public Health Advisory about safety-related changes in the indications for Viramune (nevirapine), used in combination therapy to treat HIV. The labeling now recommends against starting nevirapine therapy in women with CD4+ cell counts greater than 250 cells per cubic millimeter unless benefits clearly outweigh risks. These changes now appear in the Indications and Usage section of the labeling, and a new Medication Guide for Patients explains the risks associated with nevirapine treatment.

Although both men and women on nevirapine can develop symptomatic liver toxicity, women have an overall risk three times higher than men. And although symptomatic liver toxicity can occur at any CD4+ count, women with CD4+ counts greater than 250 have 12 times the risk of women with lower CD4+ counts. The cutoff point for men is considerably higher—400 cells per cubic millimeter.

Symptomatic liver toxicity is more common with nevirapine than other similar drugs used to treat HIV. It usually occurs within the first few weeks of dosing, and can lead to liver failure even if lab results are being monitored.

Nonetheless, nevirapine is continuing to be used for several reasons. First, triple antiretroviral regimens using drugs like nevirapine are the standard of care in treating HIV. And since drug resistance can develop to any of these agents, it's important to have many drug options available.

The Public Health Advisory also points out several advantages to nevirapine compared to other antiretrovirals. For example, unlike other antiretroviral drugs, symptomatic liver toxicity has never been reported when nevirapine is given to a pregnant woman in a single dose to prevent perinatal HIV infection. Also, symptomatic liver toxicity hasn't been reported when nevirapine is administered to children.

Additional Information:

FDA Public Health Advisory for Nevirapine (Viramune).
http://www.fda.gov/Drugs/DrugSafety/PublicHealthAdvisories/ucm051674.htm


Medtronic Recalls Certain Defibrillators

Medtronic, Inc., is recalling two of its defibrillator models. First, the company has issued an alert about certain Lifepak 500 automatic external defibrillators because in some cases, these devices may not recognize that the electrodes are connected to the patient, and thus may not defibrillate those patients.

The company is also recalling certain Medtronic implanted defibrillators because some of their batteries can develop internal short circuits. If this happens, the device can quickly become inoperative.

Additional Information:

FDA MedWatch Safety Alert – Medtronic LIFEPAK 500 Automated External Defibrillators.
http://www.fda.gov/MedicalDevices/Safety/RecallsCorrectionsRemovals/ListofRecalls/ucm064172.htm


Medtronic Recalls Certain Defibrillators

Medtronic, Inc., is recalling two of its defibrillator models. First, the company has issued an alert about certain Lifepak 500 automatic external defibrillators because in some cases, these devices may not recognize that the electrodes are connected to the patient, and thus may not defibrillate those patients.

The company is also recalling certain Medtronic implanted defibrillators because some of their batteries can develop internal short circuits. If this happens, the device can quickly become inoperative.

Additional Information:

FDA MedWatch – Medtronic Implantable Defibrillator models.
http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm152997.htm


Alert on IV Flush Syringes

FDA has issued nationwide alerts that warn against using certain preloaded syringes that contain heparin or saline flushes for IV catheters. The syringes are not approved by FDA and in fact, the flushes may have caused Pseudomonas fluorescens (P. fluorescens) infections in a number of patients.

The syringes are manufactured by IV Flush, LLC and distributed by Pinnacle Medical Supply, of Rowlett, Texas. They were sold through distributors to hospitals, clinics and home health care agencies.

Health care facilities and consumers who have these preloaded syringes should not use them. Instead, immediately return them to IV Flush, LLC or the original distributor.

Consumers or health care facilities with questions can contact the company at
1-972-463-7389, or FDA at 1-800-FDA-0178. If you suspect that your patients may have been infected from these products, you should also report these cases to your state or local health department, the FDA and CDC.

Additional Information:

FDA Press Release - FDA Renews Nationwide Alert on IV Flush Brand of Heparin or Sodium Chloride Intravenous Catheter Flushes in Light of New Contamination Reports.
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2005/ucm108409.htm


Patient Deaths Caused by Unlabeled Containers

The Institute for Safe Medication Practices is warning about the danger of having unlabeled containers in the OR. They report on a recent case in which chlorhexidine antiseptic solution was injected into a patient's artery instead of a contrast medium prior to cerebral angiography.

The patient died several weeks later, after undergoing a leg amputation, a stroke and multiple organ failure. This happened because the two solutions, both clear, were present on the sterile field in identical, unlabeled basins.

ISMP also cites an earlier case in which a cup containing glutaraldehyde, a preservative, was near a similar cup containing some of the patient's spinal fluid, which had been removed earlier to reduce cerebral pressure. Both cups were unlabeled. The glutaraldehyde was mistakenly drawn into a syringe, it was injected intrathecally, and the patent died.

Here are some of ISMP's recommendations to prevent these kinds of tragedies:

Require labels on all medications and medication containers on and off the sterile field, and also in perioperative units, even if there's only one medication or solution involved.

Make labeling easy by purchasing sterile markers and labels that can be opened onto the sterile field during procedures.

If drug or solution names are similar, highlight the differences on the label.

If possible, use skin antiseptic products in prepackaged swabs or sponges, to distinguish them from medications.

When preparing the labels, require the scrub person and circulating nurse to verify the information by reading aloud the product name, strength and dosage from the labels.

When passing a medication to the clinician performing the procedure, read the label aloud.

Finally, discard any unlabeled medication or solution found in the area, and report the event as a hazardous condition.

Additional Information:

ISMP Medication Safety Alert. December 2, 2004.
http://www.ismp.org/MSAarticles/loud.htm


Confusion between Acetylcysteine Dosage Forms

The Institute for Safe Medication Practices has cautioned about possible mix-ups between different dosage forms of the mucolytic agent, acetylcysteine.

For many years, acetylcysteine products, such as MUCOMYST, were only approved for bronchopulmonary use and they were intended to be administered by nebulization. But ISMP points out that acetylcysteine was frequently administered orally off-label for other purposes, particularly to treat acetaminophen overdoses.

In 2004, FDA approved an IV formulation of acetylcysteine called ACETADOTE to treat patients with acetaminophen overdoses. Now, with nebulization, oral, and IV routes all being used, ISMP says there's bound to be some confusion, especially since the oral product comes in a vial with a rubber stopper, making it look like an injectable product.

In one recent case, an error was averted when the nurse called a pharmacist to question whether the oral drug that she received from the pharmacy was compatible with the patient's IV fluids. In another case, a patient being prepped for radiology was given the oral medication intravenously.

To confuse matters further, another source of error is that the drug may be ordered in milligrams, but some non-injectable product labels list the strength in percent only. So ISMP makes several suggestions.

First, depending on the route of administration, consider dispensing acetylcysteine in different packaging or with visible auxiliary labels.
For oral administration, the pharmacy could remove the drug from the original vial and place the proper dose in an oral solution bottle with a label showing the drug, strength, and route of administration. Similar labels should be placed on vials dispensed for IV administration or nebulization.

Include a caution on drug administration records so that it's clear which product to use.

Alert staff that there's a new, FDA-approved formulation for IV use with acetaminophen overdoses.

And finally, remind them that if the route of administration is unclear, double check with the prescriber.

Additional Information:

ISMP Medication Safety Alert. August 12, 2004.
http://www.ismp.org/MSAarticles/calendar/Aug04.htm


Mixups between Extended-release Formulations of Same Drug

A recent ISMP alert warns about the danger of confusing various extended- release forms of the same drug. They also point out that the problem is likely to increase as drug manufacturers expand their product lines to include more forms of the same drug.

ISMP cites the example of Wellbutrin, which is now available as Wellbutrin, Wellbutrin XL, and Wellbutrin SR. Or Metadate, which is available as Metadate ER and Metadate CD. Or Ritalin LA and Ritalin SR. Or Depakote and Depakote ER. ISMP cautions that these various extended release formulations are not substitutable.

Here are some of the steps ISMP recommends to prevent mixups.

First, ensure that staff who prescribe, dispense and administer these products know about the different extended-release formulations and their dosing schedules.

Design your computer mnemonics so that the various dosage forms don't appear on the screen simultaneously, or place alerts on the screen to distinguish between them.

Consider warnings on pharmacy shelves to prevent errors in selecting the drugs.
And alert patients about the importance of these suffixes in the names of their drugs, so they can help to identify an error before taking the drug.

Additional Information:

ISMP Medication Safety Alert. October 16, 2003.
http://www.ismp.org/MSAarticles/calendar/Oct03.htm#Oct16



FDA Patient Safety News is available at www.fda.gov/psn