FDA

The Institute for Safe Medication Practices (ISMP) recently warned about the dangers of accidentally giving topical thrombin intravascularly. Thrombin applied topically can help stop oozing blood and minor bleeding from capillaries and small veins. Some thrombin products are produced as a frozen solution. Others come as a powder to be reconstituted, sometimes packaged with a parenteral syringe to help prepare and withdraw the product.

Because of its clotting action, topical thrombin should only be applied to the surface of bleeding tissue. It should never be injected systemically, because that can lead to extensive intravascular clotting and death. ISMP points out that topical thrombin has been mistaken for parenteral medication and administered intravascularly, despite labeling on the thrombin vials that warns against injecting the product. The confusion may arise because the vial-and-syringe packaging of some topical thrombin products makes them look like parenterals.

In a recent article, the Institute for Safe Medication Practices (ISMP) highlighted several potential safety problems when hospitals switch from multiple dose vials of insulin to insulin pens.

ISMP points out that there are certain safety advantages in using the pens. For example, the pens may reduce the chance of drug mix-ups, since each pen is pre-labeled with product name and strength, and the patient's name can be on the label as well. But ISMP also notes a number of potential safety problems to watch out for when hospitals switch to pens.

One possible problem is needlestick injuries, which could happen because the pen may make it difficult to see the injection site. Also, some needles do not have needle guards, so a needlestick can occur after the injection.

The Food and Drug Administration wants to be sure that consumers know about new warnings on over-the-counter vaginal contraceptive products that contain the spermicide ingredient nonoxynol 9 (N9). These products include spermicidal gels, foams, films and inserts.

These warnings emphasize that nonoxynol 9 does not protect against infection from HIV, the virus that causes AIDS, or other sexually transmitted diseases. The warnings are intended to correct a mistaken impression that nonoxynol 9 protects against STD infection, including HIV/AIDS. In fact, using it may actually increase the risk of contracting HIV/AIDS from an infected partner, because nonoxynol 9 can irritate the vagina and rectum.

The new labeling makes several other points:

• Nonoxynol 9 contraceptive products are for vaginal use only, not rectal use. If you or your partner experience burning, itching, a rash or irritation of the vagina or penis, stop using it and talk to your doctor.

The Institute for Safe Medication Practices (ISMP) and FDA are warning healthcare professionals that potentially fatal dosing errors continue to occur with the anti-epileptic drug Cerebyx (fosphenytoin), despite clarifications in the drug's labeling that date back to 1999. FDA's MedWatch program has reports of seven cases where young children received an overdose of Cerebyx and died.

Cerebyx doses are expressed as phenytoin equivalents (PE). The problem is that electronic and printed displays in many facilities list the drug as "50 mg PE/mL, 10 mL." That could cause users to believe that a 10 mL vial contains just 50 mg PE rather than 500 mg PE, which could lead to a significant overdose.

FDA has informed the health care community about ongoing safety reviews of several drugs. FDA is doing this as part of its commitment to inform health care professionals and the public about its ongoing drug safety reviews. Because the information is preliminary and there is scientific uncertainty, FDA is not taking regulatory action at this point, and is not advising health care professionals to stop using the drugs. FDA is continuing to evaluate the safety of these products, and will provide updates as more information becomes available.

One communication concerns the possibility of an increased risk of heart attack among HIV patients taking the nucleoside reverse transcriptase inhibitors Ziagen (abacavir) and Videx (didanosine). This information comes from an ongoing international study of over 30,000 HIV patients. This study did not address the heart attack risk with tenofovir or emtricitabine, two other nucleoside reverse transcriptase inhibitors.

FDA is taking action against companies marketing injectable colchicine, which is an unapproved form of the drug. Colchicine is an anti-inflammatory used in the treatment of gout. Colchicine tablets, which are less hazardous, are not affected by FDA's action at this time.

The injectable form of colchicine is especially hazardous because the therapeutic index, which is the margin between an effective dose and a toxic dose, is very narrow. Also, certain side effects that might alert the clinician that the dose is too high do not appear until the patient has already reached toxic levels, which adds to the problem.

Because of its toxicity and the availability of safer therapies, injectable colchicine is rarely used to treat gout anymore. But some practitioners are using this product to treat back pain. FDA believes that the risks of this treatment outweigh the benefits.

Over the past several months, FDA has been alerting healthcare professionals and the public about medical products that may contain contaminated heparin, which has been associated with a number of serious adverse events. Here is an update and recommendations on this continuing issue.

Heparin is an anticoagulant commonly used subcutaneously and intravenously in patients undergoing kidney dialysis, certain types of cardiac surgery and other procedures. It is also used in lock flush solutions to maintain the patency of IV catheters, and as a coating or ingredient in certain medical devices and diagnostic products.

FDA recently approved a new medical adhesive called Artiss to attach skin grafts onto burn patients. Artiss is made by Baxter Healthcare.

Artiss has a lower thrombin concentration than other fibrin sealants, which gives surgeons more time to position the skin graft over a burn before the graft starts to adhere to the skin.

In a multicenter clinical trial, Artiss was compared to surgical staples using two different wound sites on the same patient. The results showed that Artiss was comparable to staples in achieving complete wound closure. The most frequent adverse events, which were seen in both treatment groups, included bleeding and fluid collection in the tissues. Both of these events are common during skin grafting.

Additional Information:

FDA Press Release. FDA Approves New Medical Adhesive to Treat Burn Patients. March 29, 2008.

http://www.fda.gov/bbs/topics/NEWS/2008/NEW01807.html

Keeping glucose levels under control can help people with diabetes feel better and also lower the risk of blindness, kidney disease, and nerve damage. Very high or very low blood sugar can have serious consequences.

Although blood glucose meters are fairly simple to operate, many things can go wrong if the user isn't careful. Here are some tips that can help people with diabetes get accurate results from their glucose meters.

• Be prepared before you do the test. Carefully read all instructions for your meter and test strips. Calibrate the meter or test it to be sure it's calibrated before you use it.

• Be sure that you're using test strips that are specified to work with your meter. Even if an incorrect test strip fits in your meter, it could give you the wrong results. Don't use test strips from a cracked or damaged bottle and don't use test strips that have passed their expiration date.

FDA news

n an April 4, 2008 letter, Cubist Pharmaceuticals advised healthcare professionals not to use the drug Cubicin with ReadyMED elastomeric infusion pumps manufactured by Cardinal Health. Cubicin (daptomycin for injection) is an antibiotic used to treat certain bacteremias and complicated skin infections.

The company's letter says that a potentially significant impurity has been isolated from reconstituted Cubicin that was stored in ReadyMED pumps. The impurity, 2-mercaptobenzothiazole (MBT), is used in rubber manufacturing. MBT has been reported to leach into medical products from rubber stoppers and syringe components in the past.