Paroxetine and suicide risk.

Court documents released in January this year suggest that GlaxoSmithKline withheld trial data that showed an increased risk of suicide associated with the use of paroxetine for 15 years. It was not until 2006 that GSK alerted people to the increased suicide risk associated with the use of this drug. It appears that the company had trial data showing an eightfold increase in suicide risk as early as 1989.

There are currently around 30 cases being brought against GSK in the USA, linking suicides and suicide attempts to the use of paroxetine. The analysis of the trial data focuses on the 'washout' phase before a trial starts, during which subjects stop taking all or most other medications to avoid confusion with results from the trial itself. Because the washout happens before patients randomly receive either the drug or a placebo, adverse events during this time cannot be attributed to the trial and so are seldom, if ever, included in the results. But GSK researchers who submitted data on paroxetine to the US Food and Drug Administration in the late 1980s and early 1990s included suicides and suicide attempts from the washout period in the results from the placebo arm of the trial, but not from the paroxetine arms. It is possible that if the washout results had been excluded, the results would have shown an eightfold risk of suicidal behaviour in adults.

New Scientist 2008; 9 February: 12.