Drug labels in the United States often omit information showing the severity of side effects or that a medicine is not very effective, two doctors said Wednesday.
The result can be a document skewed toward making a medicine seem safer and more effective than it really is, they wrote in a commentary in the New England Journal of Medicine.
Much critical information that the Food and Drug Administration has at the time of approval may fail to make its way into the drug label and relevant journal articles, wrote Drs. Lisa Schwartz and Steven Woloshin of the Dartmouth Institute for Health Policy and Clinical Practice in Hanover, New Hampshire.
The labels are written by the manufacturers and the wording is negotiated with the FDA, which gives final approval.
But key information can be missing, Woloshin said in a telephone interview. How can I decide if the potential harms of this drug are worth the risk if I don't know how well the drug works, and vice versa? he asked.
One example is Sepracor's four-year-old sleep drug Lunesta, promoted with an advertising campaign that cost $750,000 a day in 2007.
The company generated sales of $600 million last year and became a wholly-owned subsidiary of Dainippon Sumitomoto Pharma Co Tuesday.
The label says, without specifics, that Lunesta was superior to a placebo.
But test results submitted to the FDA showed that in the largest and longest study, Lunesta patients still met criteria for insomnia and reported no clinically meaningful improvements in next-day alertness or functioning, Schwartz and Woloshin wrote.
Sepracor responded that more detailed information about its products, beyond what the FDA wants, is always available to healthcare providers who ask for it, including from the company's scientific staff.
A similar example is Takeda Pharmaceutical Co's insomnia drug Rozerem. Its label omitted laboratory data showing it still took 31 minutes, for adults over age 64, and 24 minutes for younger adults to fall asleep once they took the drug, compared with 38 minutes with a placebo.
In addition, volunteers reported no subjective improvements in total sleep time, sleep quality, or the time it took to fall asleep, the researchers said. Those data were also omitted from the label.
Sometimes what gets lost is data on harms, said Schwartz and Woloshin in their commentary. Novartis' Zometa, used for cancer patients, had a warning label noting the 8- milligram dose posed a greater risk of kidney damage. But the degree of risk was not explained.
While 19 percent of the people taking the 4-milligram dose died during the study and 19 percent died taking a comparison drug, 33 percent died when given the 8-milligram dose of Zometa.
Seven years passed before the label was changed to explicitly tell doctors not to use the higher dose, but no details were given.
Novartis and Takeda had no immediate comment.
Woloshin said he and his colleagues had come up with a better format to make the scope of the risks and benefits clearer to consumers.
Last year, the FDA's Risk Advisory Committee voted unanimously to endorse it, he said. They are scheduled to meet with the agency on the issue again next month.