Suicide rates similar with SSRIs and tricyclics
Rates of suicidal behaviour, which can increase after patients with depression start treatment with antidepressants, are similar among users of selective serotonin re-uptake inhibitors and tricyclic antidepressants, according to researchers from Boston collaborative drug surveillance programme, Boston University.
Hershel Jick and colleagues used data from the UK General Practice Research
Database to estimate the relative risks of non-fatal suicidal behaviour
for patients starting treatment with fluoxetine, paroxetine, amitriptyline
or dothiepin. Study participants (555 cases and 2,062 matched controls)
could have used only one of the antidepressants, and had to have received
at least one prescription for the drug within 90 days before their suicidal
behaviour.
They found that suicidal behaviour increased in the first month after
starting antidepressants and that this association was similar for all
of the four drugs studied. “We think the most likely explanation
for this finding is that antidepressant treatment may not be immediately
effective, so there is a higher risk of suicidal behaviour in patients
newly diagnosed and treated than in those who have been treated for a
longer time.”
Compared with dothiepin, the odds ratios for amitriptyline, fluoxetine,
and paroxetine were 0.83, 1.16 and 1.29, respectively. None of the ratios
was significantly higher than for dothiepin, although the difference
for paroxetine approached statistical significance.
The researchers did not observe any substantial difference in effect
of the four drugs on people aged 10 to 19 years but say that a difference
cannot be ruled out based on their results (JAMA 2004;
292:338).
In an accompanying editorial, Simon Wessely, of the Institute of Psychiatry,
London, says: “Most UK general practitioners are now aware that
the older tricyclic drugs are more dangerous in overdose, and it remains
plausible that there is a tendency to prescribe the newer SSRIs for patients
about whom the physician has more concerns about suicidal risk. Only
a small such bias could cause the observed [possible small increase in
risk for paroxetine]. Moreover, there was no evidence for the alleged
withdrawal phenomenon, which is another of the concerns that have been
raised about the SSRIs. Stopping medication did not lead to an increased
risk, as postulated by some.”
“Whatever decision clinicians reach, careful monitoring of adolescents
(for activation, agitation, and suicidal ideation) prescribed any antidepressant
remains essential,” Dr Wessely concludes (ibid, p379). |
The
Pharmaceutical Journal
Acrobat
Reader