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Patients warned of clinical differences in thyroid meds
Two organizations representing clinical endocrinologists have warned patients taking thyroid medication, prescribing physicians, and pharmacists dispensing these drugs that clinically important differences exist between one recently approved generic levothyroxine preparation and the most widely prescribed brand of levothyroxine. The members of these organizations, the American Thyroid Association and the American Association of Clinical Endocrinologists, specialize in treatment of hormonal disorders. In June, the FDA ruled that several generic levothyroxine preparations had the same clinical effect and safety profile as certain branded products. As a result, pharmacists may substitute a patient’s current levothyroxine preparation for another.
According to bioequivalence data used to acquire FDA approval, one recently approved generic levothyroxine preparation (Sandoz Levothyroxine Sodium) is significantly more potent than the most widely used brand of levothyroxine (Synthroid). Information from bioequivalence studies submitted to the FDA show that the new generic may be as much as one-eighth more potent (+12.5%) than the widely prescribed branded product.
Furthermore, levothyroxine is a drug known to have a narrow toxic-to-therapeutic ratio with significant clinical consequences of even minor excessive or inadequate dosing. Potential adverse events include osteoporosis, atrial fibrillation, worsening of heart disease, preterm delivery in pregnancy, impaired fetal brain development, and high cholesterol.
The FDA and the societies recommend that patients switching between levothyroxine products have repeat thyroid blood testing to be certain that the treatment dose remains effective and safe.
Higher costs affect MS patients’ adherence to medications
Multiple sclerosis patients were less likely to take the generally recommended medications for their condition when their out-of-pocket cost for the prescription drugs rose, according to research from Medstat, a business of The Thomson Corp.
The study, published in the August 2004 Clinical Therapeutics, found patients would be 32% more likely to use these medications if their insurance copayments were reduced by half.
Researchers used health claims data from Medstat’s MarketScan database to analyze the treatment patterns of 1,807 multiple sclerosis patients. They tracked use of three new disease-modifying drugs — interferon beta-1a (Avonex), interferon beta-1b (Betaseron), and glatiramer acetate (Copaxone) — which slow the progression of the disease and cost about $10,000 per patient annually.
If drug copayment requirements were to decrease by 50%, the research team found, the proportion of patients who would be treated with these drugs would rise from 41.2% to 54.7%.
FDA issues warnings, label changes
The FDA and Genentech have issued a drug warning to health care providers that there is evidence of an increased risk of serious arterial thromboembolic events, including cerebrovascular accident, myocardial infarctions, transient ischemic attacks, and angina related to bevacizumab (Avastin). The risk of fatal arterial thrombotic events also is increased. In randomized, active-controlled studies conducted in patients with metastatic colorectal cancer, the risks of a serious arterial thrombotic event was approximately twofold higher in patients receiving infusional 5-FU-based chemotherapy plus bevacizumab, with an estimated overall rate of up to 5%. A revised bevacizumab package insert containing more detailed information on arterial thromboembolic events is in development. For more information, see www.fda.gov/medwatch/SAFETY/2004/safety04.htm#avastin.
Also, Aventis Pharmaceuticals have revised the Clinical Pharmacology, Precautions, and Dosage Administration sections of labeling for enoxaparin sodium injection (Lovenox), describing the need for a dosage adjustment for patients with severe renal impairment (creatinine clearance < 30 mL/ min) who have increased exposure to enoxaparin. No specific dosage adjustment is required in patients with mild or moderate renal impairment and in low-weight patients. However, low-weight patients should be observed carefully for signs and symptoms of bleeding. For more information, see www.fda.gov/medwatch/SAFETY/2004/safety04.htm#lovenox.
Finally, Centocor is informing health care professionals about safety information concerning hematologic and neurologic events with infliximab (Remicade), a biological therapeutic product indicated for the treatment of rheumatoid arthritis and Crohn’s disease.
In post-marketing experience worldwide, hematologic events including leukopenia neutropenia, thrombocytopenia, and pancytopenia, some with a fatal outcome, have been reported in patients receiving infliximab. Accordingly, Centocor has added a Warning on Hematologic Events to the labeling for the product. For more information, see www.fda.gov/medwatch/SAFETY/2004/safety04.htm#remicade.
Survey highlights importance of pharmacist/patient relationship
A national consumer survey commissioned by the American Pharmacists Association (APhA) in Washington, DC, shows that a consumer simply knowing the pharmacist’s name correlated strongly with his or her access to information that could avert serious medication risk as well as improve medication outcomes.
The survey showed that consumers are taking risks with their medications:
Although pharmacists can help consumers make the best use of their medication — and decrease the risks of using medications — most consumers are not yet making the most of their pharmacist. Among the survey findings:
Consumers who reported using a number of prescription medicines were more likely to know their pharmacist’s name, as were seniors or those in poor or very poor health. The survey showed that consumers who know their pharmacist’s name are twice as likely to ask their pharmacist the questions they have. Further, those who know their pharmacist’s name: