DRUG NAMES CAUSE CONFUSION
Recent errors reported in MedWatch.
There have been a number of reports of medication errors stemming from confusion over the brand names of several drugs: metoprolol succinate (Toprol-XL), topiramate (Topamax), and carbamazepine (Tegretol and Tegretol-XR). Toprol-XL is an extended-release version of the [beta]-blocker metoprolol succinate used in the treatment of hypertension, angina, and heart failure. Topiramate is an anticonvulsant used in the treatment of partial-onset and tonic-clonic seizures and for the prevention of migraines; off-label use is for the treatment of cluster headache. Both forms of carbamazepine are anticonvulsants, but they're used primarily in the treatment of complex partial seizures, generalized tonic-clonic seizures, and trigeminal neuralgia; off-label uses of Tegretol-XR include the treatment of several psychotic disorders, such as bipolar disorder, depression, and schizophrenia. The labeling of both Tegretol and Tegretol-XR bears a black box warning concerning aplastic anemia and agranulocytosis, serious blood dyscrasias that have been associated with the use of the drug.
The errors associated with the drugs have involved ordering, the interpretation of orders, labeling, and dispensing. The similarity of the proprietary drug names, the proximity of the drugs when stocked in the pharmacy, and a comparability in dose denominations have all contributed to the errors. But the medications differ in appearance. To view pictures of them at the MedWatch Web site (from the Food and Drug Administration [FDA]), go to http://www.fda.gov/medwatch/safety/2005/toprol_dhcp.pdf.
To minimize the risk of error involving prescription or administration of the wrong medication, the trade and generic names of the drug, and the indication, should be written on all medication orders. Nurses who administer drugs should confirm that the drug ordered is appropriate to the patient's condition, and if its appearance is not what they're used to or had expected, check carefully to confirm that it's the intended medication. Patients and their families should be taught the name of the prescribed drug, informed of its intended purpose, apprised of its appearance, and instructed to question the appropriateness of any dispensed medication that has an appearance different from what they expected. Nurses should report any error involving these or any other drugs to the FDA MedWatch program: http://www.fda.gov/medwatch.
AstraZeneca. Dear healthcare professional: [letter; Toprol-XL (metoprolol succinate)]. 2005 Sep 22. http://www.fda.gov/medwatch/SAFETY/2005/toprol_dhcp.pdf; Ortho-McNeil Neurologics, Inc. Dear healthcare professional: [letter; Topamax (topiramate)]. 2005 Sep. http://www.fda.gov/medwatch/SAFETY/2005/DearHealthcareProfTopamax.pdf.
STRATTERA: A NEW BLACK BOX WARNING
A public health advisory has been issued.
The Food and Drug Administration has issued a public health advisory to inform health care providers and caregivers that the drug atomoxetine (Strattera), used to treat attention deficit-hyperactivity disorder, has been associated with a heightened risk of suicidal ideation in children and adolescents taking the drug. A boxed warning has been added to the drug labeling and a medication guide will be developed for distribution with each prescription filled. The finding emerged from the manufacturer's analysis of 12 short-term, placebo-controlled clinical drug trials of six to 18 weeks' duration in which 1,350 patients received atomoxetine and 851 received a placebo. The incidence of suicidal ideation during therapy with atomoxetine was around four per 1,000 patients, compared with none among control subjects. One patient taking the drug attempted suicide. In a comparable analysis of the effects of atomoxetine on adult patients, no heightened risk of suicidal ideation was identified.
Nurses should instruct the parents of a child or adolescent taking atomoxetine to closely observe him for clinical worsening, agitation, irritability, suicidal thoughts or behavior, and unusual changes in behavior. Such patients should be most closely monitored during the first few months of therapy and whenever the dosage is changed. Children and adolescents taking atomoxetine should be closely monitored also by a health care professional, and parents should be informed of the importance of making frequent follow-up visits during the course of the drug therapy. It should be emphasized that the effect is uncommon but that because it's a potentially serious one, consistent close monitoring is essential. Finally, parents should be instructed to read the medication guide each time a prescription for atomoxetine is filled, as the information in it may have changed.
U.S. Food and Drug Administration. FDA alert for healthcare professionals: atomoxetine (marketed as Strattera). 2005 Sep. http://www.fda.gov/cder/drug/InfoSheets/HCP/atomoxetinehcp.pdfFDA news: FDA issues public health advisory on Strattera (atomoxetine) for attention deficit disorder. 2005 Sep 29. http://www.fda.gov/bbs/topics/news/2005/new01237.html; U.S. Food and Drug Administration. FDA patient information sheet: atomoxetine (marketed as Strattera). 2005 Sep. http://www.fda.gov/cder/drug/InfoSheets/patient/AtomoxetinePIS.pdf.
MENINGOCOCCAL VACCINE AND GUILLAIN-BARRE SYNDROME
An alert is issued after five reports suggest an association.
The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) have issued a joint alert to consumers and health care providers concerning five reports of cases of Guillain-Barre syndrome occurring after the administration of Menactra, a quadrivalent (A, C, Y, and W135) meningococcal conjugate vaccine. Guillain-Barre syndrome affects the neurologic system, producing muscle weakness, usually in the arms and legs, that can be severe enough to necessitate hospitalization. The meningococcal infection that the vaccine prevents is the principal cause of bacterial meningitis, with which approximately one in 100,000 people are infected annually. Ten percent to 14% of such patients die, and 11% to 19% retain permanent disability. Premarketing studies of the vaccine revealed no cases of Guillain-Barre syndrome among more than 7,000 recipients of the vaccine.
The five reported cases of Guillain-Barre syndrome occurred in New York, Ohio, Pennsylvania, and New Jersey, in patients 17 or 18 years old who developed symptoms two to four weeks after vaccination. At present, the number of case reports is small enough to be considered within the realm of probability, meaning that this number of cases could have occurred in the population in the absence of vaccination, but the time of the onset of the symptoms is of concern to the CDC and the FDA. Like other types of adverse effects, those of a vaccine are not always reported to the FDA, and the number of cases of Guillain-Barre syndrome reported therefore may not reflect the actual number of patients stricken with it. The FDA and CDC request that any cases of Guillain-Barre syndrome occurring after Menactra vaccination be reported to the Vaccine Adverse Event Reporting System at http://www.vaers.hhs.gov.
U.S. Food and Drug Administration. FDA news: FDA and CDC issue alert on Menactra meningococcal vaccine and Guillain Barre Syndrome. 2005 Sep 30. http://www.fda.gov/bbs/topics/news/2005/new01238.html.
A NEW PRECAUTION CONCERNING PAXIL
A possible association with congenital malformations.
The preliminary results of a retrospective epidemiologic study have prompted the revision of the labeling of paroxetine (Paxil), a selective serotonin reuptake inhibitor used to treat depression, and the controlled-release form of the drug, Paxil CR. The pregnancy category assigned to the drug has not been changed as a result of the new analysis. The labeling always has borne the designation "pregnancy category C," indicating that controlled studies of the drug to rule out fetal risk have not been conducted in pregnant women and that it should be taken during pregnancy only if the expected benefit outweighs the possible risks.
In the study, conducted by the manufacturer, the risk of major congenital malformations in infants born to 3,581 women taking paroxetine or other antidepressants during the first trimester of pregnancy was assessed. The analysis suggested paroxetine may be associated with a higher risk of congenital malformations than are other antidepressants. The congenital malformations most commonly seen were cardiovascular, particularly ventricular septal defects. A separate study, based on data from the Swedish Medical Birth Registry, of 4,291 infants exposed to paroxetine in early pregnancy did not reveal a heightened risk of major malformations. The findings of both studies will be included in the "Precautions" section of the drug label, and nurses should discuss them with their patients. If paroxetine is to be discontinued, the directions for discontinuation (found in the "Discontinuation of Treatment" subsection of the "Precautions" section of the label) should be followed closely. To view the results of GlaxoSmithKline's study posted on its clinical trial register, see http://ctr.gsk.co.uk/welcome.asp.
GlaxoSmithKline. Dear healthcare professional: [letter; Paxil (paroxetine HCL)]. 2005 Sep. http://www.fda.gov/medwatch/safety/2005/Paxil_dearhcp_letter.pdf.