GlaxoSmithKline yesterday fought back against findings that its antidepressant Seroxat/Paxil (paroxetine) had been linked to an increased risk of suicidal behaviour amongst adults, arguing that the research was misleading and serves only “to cause confusion and unnecessary concern for patients” [[22/08/05b]]. The analysis, conducted by Norwegian scientists, included unpublished data for Seroxat and concluded: “Patients and doctors should be warned that the increased suicidal activity observed in children and adolescents taking certain antidepressant drugs may also be present in adults.”

The review of 16 trials found seven suicide attempts among those taking the drug and only one in a patient on placebo. However, GSK says the sub-analysis is misleading as it focuses on data collected 15 years ago, which formed part of its successful regulatory filing in 1989 for Seroxat/Paxil. Furthermore, the company claims, the scientists did not acknowledge the current body of data, which are “significantly more extensive and which has been recently reviewed by EU authorities.”

Europe’s advisory body – the CHMP – last year cleared the risk:benefit profile of Seroxat in adults [[10/12/04a]], but the waters have not yet calmed and the US Food and Drug Administration recently announced that it is lining up to evaluate the risk of the selective serotonin reuptake inhibitor class of antidepressants in adults [[31/05/05g]].

Doctors are already precluded from prescribing antidepressants for children and adolescents after a link to suicidal behaviour was observed and drug regulators slapped black box warnings on their use in this patient population [[06/12/04a]], [[18/10/04b]]. However, GSK’s response points to an increasing sensitivity of pharmaceutical companies to negative commentary, in the wake of last week’s decision to find Merck & Co negligent in the first ever Vioxx (rofecoxib) trial and award the plaintiff in excess of $250 million [[22/08/05a]].