Diet drug risks may have been known years ago
December 11, 1997
Web posted at: 8:06 p.m. EST (0106 GMT)
(CNN) -- Questions are being raised about whether drug
companies and federal regulators knew that two popular diet
drugs were linked to heart damage years before they were
pulled from the U.S. market.
In September, the U.S. Food and Drug Administration called
for the withdrawal of the two drugs -- Redux, known
generically as dexfenfluramine, and fenfluramine, the "fen"
in the diet drug combination "fen-phen" -- after reports of
an unusual heart valve disease.
In a letter to the New England Journal of Medicine, Belgian officials said they received similar reports dating back
to 1994. Thirty-one women in that country with heart valve problems had been taking diet drugs, including fen-phen, the letter said.
In a statement released Thursday, the FDA acknowledged it had
heard about some of the side effects with the diet pills
before it approved Redux, the newer of the two drugs.
"However, these scattered reports were not easily linked to
one another because they did not specify heart valvular
disease as the primary adverse event and were identified more
generally as heart, kidney or lung disorders," the FDA
Wyeth-Ayerst, manufacturer of the two drugs in the United
States, said in a statement that it had informed the FDA of
the reactions, as required.
But the drug company and the FDA both said the Belgian
reports were complicated by the fact that many of the women
were also using Chinese herbs to lose weight.
In its statement, Wyeth-Ayerst said that while some of the
cases included heart valve problems, the patients' conditions
"were ascribed to their use of Chinese herbs." The company
also said that "to our knowledge, the Belgian authorities
took no action regarding either (drug) based on the reports."
"Wyeth-Ayerst does not believe these cases, even with the
benefit of hindsight, demonstrate that heart valve problems
are caused by either of these drugs," the statement said.
The FDA continues to evaluate matters relating to
the two drugs and their effects on public health, and
Wyeth-Ayerst has set up a panel to investigate the