Show #23, January 2004
Show #23, January 2004
|Prussian Blue Approved to Treat Internal Radiation Contamination|
FDA recently approved Prussian blue to treat people who have been internally contaminated by ingesting or inhaling particles of radioactive cesium-137 or thallium. The product is called Radiogardase, and it's made by the German firm Heyl. Prussian blue is the first available therapy to help reduce the body's burden of these elements. It works by trapping cesium-137 and thallium in the intestine so that they can be eliminated in the stool rather than reabsorbed. Prussian blue has been used for this purpose over the last several decades.
The FDA encouraged manufacturers to submit marketing applications for Prussian blue, to help make drugs to treat radiation contamination more widely available in the event of a terrorist attack. Having the approval will help assure that the product meets high standards of quality and that proper instructions for its use are available.
Clinicians should know that Prussian blue can be used to treat internal radiation contamination from Cesium-137 that may result from from a terrorist event, such as a "dirty bomb" attack. It is also effective in treating thallium poisoning. We are not aware of evidence that Prussian blue is effective against other radioactive materials that might be present in a “dirty bomb.” When the kind of radioactive contamination isn't known, Prussian blue should be given together with other drugs, such as potassium iodide, calcium or zinc DTPA, or sodium alginate, that are known to be effective in treating contamination from other radioactive substances.
Prussian blue should be taken as soon as possible after exposure. However, even when treatment can not be started right away, patients should be given Prussian blue as soon as it becomes available because it is still effective even after some time has elapsed.
The most commonly reported side effects are constipation and stomach upset.
- FDA Drug Information - Prussian Blue (ferric hexacyanoferrate (II)) for Treatment of Internal Contamination with Thallium or Radioactive Cesium.
|Counterfeiting of PROLENE|
ETHICON, Inc. recently issued an alert about a counterfeit mesh product labeled as PROLENE. PROLENE is a nonabsorbable polypropylene mesh used in the repair of hernias and other fascial deficiencies. ETHICON says that the counterfeit product is a flat mesh measuring 3' x 6' with a product code of PMII. So far, the affected lot numbers are RBE609 and RJJ130.
The company says that there are some differences that may distinguish the counterfeit product from authentic PROLENE. For example, the counterfeit mesh may have a tighter asymmetrical weave, compared to the open linear weave of authentic PROLENE mesh. The counterfeit product may have a jagged end along the 3" side, where authentic PROLENE mesh is smooth. And the ETHICON logo on the counterfeit box appears in a thicker typeface than authentic PROLENE.
ETHICON is advising physicians, nurses and other healthcare professionals to carefully examine all 3” x 6” flat mesh PROLENE before using it. If you receive any of this product that you suspect is counterfeit, quarantine it so it won't be used. And contact your distributor for return instructions.
FDA is testing samples of suspected counterfeit material for composition and sterility. We'll make the results available on our web site. In the meantime, you should continue to monitor patients implanted with suspected counterfeit mesh for infection or any other adverse outcome, just as you would a patient with any mesh implant.
If you have medical questions regarding suspected counterfeit product, you can contact the ETHICON customer service center at 1-877-ETHICON.
|Pediatric Antidepressants and Suicidality|
In a previous edition of FDA Patient Safety News, we told you about a possible increased risk of suicidal thinking and suicide attempts in children and adolescents being treated with Paxil for major depressive disorder or MDD.
Now, in a new advisory, FDA is alerting health care professionals about reports of suicidal ideas and attempts in pediatric MDD patients being treated with a variety of antidepressant drugs in clinical trials.
FDA's preliminary review of 8 antidepressant drugs in clinical studies suggest that there may be an excess of suicidality reports related to several of these drugs compared to placebo.
The FDA advisory notes that there have been stories in the news media and in professional journals reporting on suicide-related events when antidepressants are used in children, but the advisory points out that these events are very difficult to interpret without a control group, since they also occur in untreated patients with depression.
At this point, it's too early to tell whether there's a clear causal link between the use of these drugs in children and increased suicidal thoughts or actions. The eight drugs have been used on more than 4,100 pediatric patients in clinical trials, and there have been no reports of completed suicides to date. But an increased risk of suicidality can't be ruled out for any of these antidepressant drugs. FDA's advisory says that additional data and analysis are needed, and FDA has scheduled a meeting to promote a public discussion of the available data.
FDA’s advisory points out that clinical trials have shown only one drug, Prozac effective in treating children with MDD. But it also notes that the failure of any single study to show effectiveness doesn't necessarily mean that the drug is not effective. The advisory recognizes that there aren't many established treatment options for children with MDD. So clinicians treating them often must choose among treatments available for adults with MDD.
The advisory also stresses that these antidepressant drugs should be used with caution, whether treating children or adults. It points out that the drug labeling already states that suicide attempts are an inherent possibility in MDD and may persist until significant remission occurs. So high risk patients should be closely supervised during initial drug therapy. And, in order to reduce the risk of overdose, prescriptions should be written for the smallest number of tablets consistent with good patient management.
The advisory also cautions that patients should not discontinue using any of these drugs without first consulting with their physicians. For some of these drugs, it's important that they're not abruptly discontinued. The advisory tells parents and other caretakers of children on antidepressants to talk to their doctors about these drugs.
You can find a copy of the FDA advisory on our web site. And as more information becomes available, we'll update you on future editions of FDA Patient Safety News.
- MedWatch Safety Alert. Public Health Advisory - Suicidality in Pediatric Patients Treated with Antidepressants for Major Depressive Disorder.
|Caution on Potential Fires with Sevoflurane for Inhalation|
Abbott Laboratories has sent a letter to healthcare professionals about its product Ultane or sevoflurane, a general anesthetic. The letter warns about rare reports of fires or extreme heat in the respiratory circuit of anesthesia machines when this product is used.
Although the exact cause of the fires has not yet been determined, in most cases the CO2 absorbent material used with the Ultane had become desiccated. This may have led to an increased exothermic reaction between the sevoflurane and the absorbent material.
The letter from Abbott provides a number of recommendations to reduce the risk of fires or excessive heat. Let us summarize them.
First, replace the CO2 absorbent if you suspect it's become desiccated because it hasn't been used for a long time.
Turn off the anesthesia machine completely at the end of each clinical use. If the machine is left on, fresh gas continues to flow through it at a low rate, and this may accelerate the drying of the absorbent.
Turn off all vaporizers when not in use.
Before you use a new CO2 absorbent, check the integrity of the packaging.
Periodically monitor the temperature of the CO2 absorbent canisters.
Monitor the correlation between the sevoflurane vaporizer setting and the concentration of the inspired sevoflurane. If you notice an unusually delayed rise or an unexpected decline in the inspired sevoflurane concentration when you compare it to the vaporizer setting, this could indicate that there's excessive heating in the absorbent canister.
And finally, replace CO2 absorbents routinely regardless of what the color indicator shows. The color indicator doesn't necessarily change as a result of dessication.
There's additional important information in Abbott's letter. If you use Ultane, be sure you have a copy. You can get one on our web site, or from Abbott's Medical Information Department, at 1-800-633-9110.
|Drug Name Confusion: Keppra and Kaletra|
The drug company, UCB Pharma, has sent a letter to healthcare professionals warning of potential mixups between their drug, Keppra and another drug, Kaletra, which is a product of Abbott Laboratories.
Keppra, or levetiracetam, is an antiepileptic. Kaletra, a combination of lopinavir and ritonavir, is an antiretroviral. Of course, mixups between any drugs can expose patients to adverse events from a medication they didn't need. But in this case, a mixup could also result in an epileptic patient missing medication and possibly experiencing status epilepticus, or an HIV-positive patient not receiving critical therapy.
The two products don't look alike. What can look alike, and also sound alike, are their names, and that's the source of the problem. Here's what UCB Pharma recommends to prevent mixups:
First, write or speak the drug name clearly when prescribing these medications. Second, when it's appropriate, include the intended use of the drug on prescriptions. And third, counsel patients to check the medications they receive and bring any questions to the pharmacists's attention. In other words, encourage patients to examine the medication as soon as they receive it, and immediately let the pharmacist or physician know if it looks different from previous prescriptions for the same drug.
|Reporting Adverse Events from Vaccines|
Every year, tens of millions of vaccinations are given to children and adults in this country to prevent serious infectious diseases. FDA and CDC work together to monitor the safety of these vaccines using a registry known as Vaccine Adverse Event Reporting System, or VAERS. The VAERS registry contains reports of adverse events from patients, parents and health care providers, and it can help to identify important new vaccine safety concerns.
Take the example of the rotavirus vaccine. During the first months after this vaccine was approved, epidemiologists at FDA and CDC noticed 15 VAERS reports of infants who had developed a particular type of intestinal obstruction after receiving the vaccine. The reports signaled a potential problem, which led to further investigations. As a result, the vaccination program was suspended, and then later, as investigations verified the serious risk, the manufacturer voluntarily removed the vaccine from the market.
Of course, it takes multiple reports and thorough investigation to confirm a causal relationship between an adverse event and a vaccine. Still, VAERS reports are on the front line in making sure that vaccines are safe, by providing a rapid signal that problems may be occurring.
Sometimes VAERS reports highlight errors in prescribing or administering vaccines. For example, the VAERS registry was found to contain reports of 22 pregnant women who had received live virus varicella vaccine by mistake after being exposed to chickenpox. These women should have received a different product, varicella zoster immune globulin, or "VZIG."
In this case, FDA and CDC worked with the varicella vaccine manufacturer to publish details about the 22 cases. By publishing this information, we were able to alert health care professionals of this potential mix-up, and thus help prevent future cases.
It's important to keep the VAERS system working, and we can't do that without your help. We're asking that you report any significant adverse event that occurs after a vaccination, even if you're not sure that the vaccine caused it. It's easy to report by internet, phone, fax, or mail.
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