An antidepressant drug made here and commonly used by younger adults in Ireland and elsewhere may not be either as effective or as safe as originally believed.
According to a re-analysis of the original data from a 2001 study of paroxetine, whose active ingredient is made by GlaxoSmithKline at its plant in Cork, the drug was not effective for teens with major depression and led to serious side effects.
Sold under the brand name Seroxat in Ireland and as Paxil in the United States, the results of the original study were presented in far more favourable terms 14 years ago.
The original trial, known as Study 329, ran from 1994 to 1998 and included 275 teens with major depression. Study 329 looked at paroxetine, one member of a family of antidepressants once described as wonder drugs. The fact that the 2001 paper reported it to be both effective and safe raised serious questions about the reliability of industry-funded clinical trials.
The US Food and Drug Administration in 2002 said that the trial should be considered a failure because the depressed youth taking paroxetine didn’t do better compared to those taking the placebo. The previous study had found that the use of the drug was generally tolerated well and effective for major depression amongst adolescents. The new data analysis, published by the medical journal BMJ, found that paroxetine can make some teens suicidal and likely to harm themselves.
“There have been warnings about paroxetine for a long time,” including a 2007 Food and Drug Administration advisory on the risk of increased suicidality when anti-depressants like paroxetine or imipramine are used to treat people age 18 to 24, according to Dr Jon Jureidini of the University of Adelaide in Australia. The authors of the 2001 study did not report this side effect, although the evidence was there, said Dr Jureidini, a co-author of the re-analysis.
“A broad community of people around the world have raised concerns,” he told Reuters news agency.
A spokesperson for GSK said yesterday that the re-analysis has no impact in terms of patient safety or the existing regulatory information on the drug.
“The findings from this team’s analysis appear to be in line with the longstanding view that there is an increased risk of suicidality in paediatric and adolescent patients given antidepressants like paroxetine,” said GSK, in a statement.
“This is widely known and clear warnings have been in place for more than a decade. As such this reanalysis doesn’t affect patient safety.”
A spokesperson for the Health Products Regulatory Authority said: “The HPRA has recommended for some time that paroxetine should not be used for the treatment of children and adolescents under the age of 18 years.”
This advice follows an EU review of data from controlled clinical trials in paediatric patients completed in 2005 which found paroxetine to be associated with increased risk for suicidal behaviour and hostility.
“This is a subtle form of manipulation of the analysis of the data and interpretation of the results that may actually happen quite often,” said Prof David Henry of the Institute for Clinical Evaluative Sciences in Ontario, Canada, who co-authored an editorial in the BMJ on the importance of clinical data sharing.
“Statistical analysis is not black and white, you can make a drug look better than it actually is,” he said.
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