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Safety issues hit Singulair,
Ziagen
Posted 7 April 2008
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The Therapeutics Goods
Administration (TGA) is monitoring the safety of two
high-profile drugs following the release of two ''early
communication'' alerts by the US Food and Drug
Administration late last month.
The alerts – designed to inform the public about ongoing
FDA reviews – apply to Merck Sharp and Dohme’s asthma
medication, Singulair (montelukast) and GlaxoSmithKline’s
HIV treatment, Ziagen (abacavir).
Singulair, said the FDA, was being investigated in
response to inquiries regarding possible links to
behaviour/mood changes, suicidality and suicide.
"FDA has requested that Merck evaluate Singulair study
data for more information about suicidality and suicide.
FDA is reviewing the postmarketing reports it has
received… Due to the complexity of the analyses, FDA
anticipates that it may take up to nine months to complete
the ongoing evaluations."
The TGA said it was aware of these concerns, adding that
Singulair’s Product Information already listed depression,
suicidality and psychomotor hyperactivity (including
irritability, agitation, aggressive behaviour and
restlessness) as possible adverse events.
It said while it had received no adverse reports of
suicidality in association with Singulair, there had been
two reports of depression. "The TGA is monitoring the
situation and will review the new information as it
becomes available."
In a statement released shortly after the FDA
announcement, MSD said in a cumulative analysis of its
randomised, double-blind, placebo-controlled clinical
trials involving more than 11,000 people, there were no
reports of suicidal thoughts or actions, and no "completed
suicides" in patients using Singulair.
The FDA alert issued for Ziagen (abacavir) was based on
recent findings from "The Data Collection on Adverse
Events of Anti-HIV Drugs (D:A:D) Study".
This observational study of more than 33,000 patients,
found recent use of Ziagen was associated with an
increased risk of myocardial infarction. The risk did not
appear to increase over time and appeared to be reversible
after the drug was stopped.
The FDA said GSK conducted its own analysis late last
year, but the results were inconclusive. It added that it
would continue to evaluate the overall risks and benefits
of Ziagen, and this may lead to "the need to revise
labelling for the product".
A spokesperson for GSK said the company was continuing to
work with the D.A.D group and was "taking this data
seriously".
"GSK has been keeping the TGA updated on this issue as new
information becomes available," the spokesperson said.
GSK also saw a US update to PI on its influenza treatment
Relenza last week to take into account postmarketing
reports of neuropsychiatric side effects that emerged from
Japan in the winter of 2006-2007.
"GSK is also in discussions with the TGA to include the
same information on the Australian product information
under Precautions," a spokesperson said.
Kate Woods |
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