US doctors and patients are split on approval of generic thyroid hormone
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《英国医生杂志》
Three groups representing 4600 US endocrinologists have said in a public statement that they are "deeply disappointed" that the Food and Drug Administration has approved generic substitutes for brandname levothyroxine. Patient groups have welcomed the news, however, with one group announcing on its website: "The Generics are Coming, The Generics are Coming!!!" (www.thyroid.about.com/od/thyroiddrugtreatments/a/generic.htm).
Levothyroxine is the second most commonly prescribed drug in the United States, with sales worth $1.19bn (?.64bn; �0.96bn) in 2003. Abbott Laboratories?market leader, Synthroid, had sales of nearly $820m, says IMS Health, a major pharmaceutical information and consulting company. More than 13 million people take the drug.
The American Thyroid Association, the Endocrine Society, and the American Society of Clinical Endocrinologists said: "Small differences between doses—well within the range of formulation differences that might be undetected with the current bioequivalence method—can have major clinical implications for thyroid patients, including symptoms, atrial fibrillation, osteoporosis, and uncontrolled hypercholesterolaemia."
The endocrinologists and two manufacturers had separately asked the FDA to postpone approving generic levothyroxine and to set up a workshop to discuss the matter. The FDA went ahead and approved it, however, saying that its evaluation methods were acceptable.
An FDA spokesperson told the BMJ that the agency was continuing "to work with the professional groups on a scientific exchange about this issue and is taking their concerns into consideration," so a workshop may happen in future.
Dr Paul Ladenson, spokesman for the endocrine organisations, said he was concerned about pregnant women, in whom proper levothyroxine dosage was key to development of the fetus, and about patients with thyroid cancer, in whom a high dose of levothyroxine was necessary to suppress the patient抯 own thyroid stimulating hormone, to reduce the chance of recurrence. Dr Ladenson is president elect of the American Thyroid Association and heads the endocrinology division at Johns Hopkins Medical Institutions. He said he had been a consultant to Abbott but had not renewed his agreement from the end of June.
Merrill Goozner, director of the Integrity in Science project at the Center for Science in the Public Interest, a health advocacy organisation based in Washington, DC, said he was not surprised by attempts to keep generics off the market. Doctors?concerns might be legitimate, he said, but drug companies want to delay generics and they relied on paid consultants.
US prescriptions are filled generically unless the doctor indicates "dispense as written." The FDA抯 "Orange Book" on its website (www.fda.gov/cder/ob/default.htm) describes "A for B" drugs, where one drug can be substituted for another, or "B-X" drugs, where the drug is approved but cannot be substituted for another.
Nevertheless, substitutions are often made, and neither the patient nor the doctor knows, Dr Paul Ladenson told the BMJ. He said that pharmacists in chain drug stores were often rewarded for making as many generic substitutions as possible.
Although generic levothyroxine will cost less than brandname counterparts, the endocrinologists argue that medical costs will increase because patients will need repeated titration and consultations with their doctors to check the effects of the new medication. They might receive a different generic with each prescription refill, requiring many repeat visits for titrations.
Dr Stacey Swartz, associate director of management and educational affairs for the National Community Pharmacists Association, which represents 24 000 pharmacists who own local independent pharmacies, told the BMJ that state law in the United States governs substitution. But she said that usually, if a generic is available, "the pharmacist can substitute."
Pharmacists may tell the patient about substitutions, and many pharmacies include information about substitution with the patient抯 pills. In 2003, she said, nearly half (49%) of US prescriptions were for generic drugs. When the doctor prescribes a brandname drug and the patient is concerned about the cost, the pharmacist usually phones the doctor and asks if a generic can be prescribed. In almost all cases (87%), the doctor agrees, she said.(New York Janice Hopkins T)
Levothyroxine is the second most commonly prescribed drug in the United States, with sales worth $1.19bn (?.64bn; �0.96bn) in 2003. Abbott Laboratories?market leader, Synthroid, had sales of nearly $820m, says IMS Health, a major pharmaceutical information and consulting company. More than 13 million people take the drug.
The American Thyroid Association, the Endocrine Society, and the American Society of Clinical Endocrinologists said: "Small differences between doses—well within the range of formulation differences that might be undetected with the current bioequivalence method—can have major clinical implications for thyroid patients, including symptoms, atrial fibrillation, osteoporosis, and uncontrolled hypercholesterolaemia."
The endocrinologists and two manufacturers had separately asked the FDA to postpone approving generic levothyroxine and to set up a workshop to discuss the matter. The FDA went ahead and approved it, however, saying that its evaluation methods were acceptable.
An FDA spokesperson told the BMJ that the agency was continuing "to work with the professional groups on a scientific exchange about this issue and is taking their concerns into consideration," so a workshop may happen in future.
Dr Paul Ladenson, spokesman for the endocrine organisations, said he was concerned about pregnant women, in whom proper levothyroxine dosage was key to development of the fetus, and about patients with thyroid cancer, in whom a high dose of levothyroxine was necessary to suppress the patient抯 own thyroid stimulating hormone, to reduce the chance of recurrence. Dr Ladenson is president elect of the American Thyroid Association and heads the endocrinology division at Johns Hopkins Medical Institutions. He said he had been a consultant to Abbott but had not renewed his agreement from the end of June.
Merrill Goozner, director of the Integrity in Science project at the Center for Science in the Public Interest, a health advocacy organisation based in Washington, DC, said he was not surprised by attempts to keep generics off the market. Doctors?concerns might be legitimate, he said, but drug companies want to delay generics and they relied on paid consultants.
US prescriptions are filled generically unless the doctor indicates "dispense as written." The FDA抯 "Orange Book" on its website (www.fda.gov/cder/ob/default.htm) describes "A for B" drugs, where one drug can be substituted for another, or "B-X" drugs, where the drug is approved but cannot be substituted for another.
Nevertheless, substitutions are often made, and neither the patient nor the doctor knows, Dr Paul Ladenson told the BMJ. He said that pharmacists in chain drug stores were often rewarded for making as many generic substitutions as possible.
Although generic levothyroxine will cost less than brandname counterparts, the endocrinologists argue that medical costs will increase because patients will need repeated titration and consultations with their doctors to check the effects of the new medication. They might receive a different generic with each prescription refill, requiring many repeat visits for titrations.
Dr Stacey Swartz, associate director of management and educational affairs for the National Community Pharmacists Association, which represents 24 000 pharmacists who own local independent pharmacies, told the BMJ that state law in the United States governs substitution. But she said that usually, if a generic is available, "the pharmacist can substitute."
Pharmacists may tell the patient about substitutions, and many pharmacies include information about substitution with the patient抯 pills. In 2003, she said, nearly half (49%) of US prescriptions were for generic drugs. When the doctor prescribes a brandname drug and the patient is concerned about the cost, the pharmacist usually phones the doctor and asks if a generic can be prescribed. In almost all cases (87%), the doctor agrees, she said.(New York Janice Hopkins T)