The second-generation or atypical antipsychotics used to treat schizophrenia are no better than older drugs in terms of efficacy or tolerability, according to a prospective study carried out at 14 community psychiatric hospitals in the UK.

But companies manufacturing atypical antipsychotics, notably Eli Lilly which makes the market leading Zyprexa (olanzapine) schizophrenia treatment, maintain that there are differences between the newer agents and that a blanket comparison with older drugs is problematic.

The three atypicals included in the study – Zyprexa, AstraZeneca’s Seroquel (quetiapine) and Janssen’s Risperdal (risperidone) – are all blockbuster medicines which are significantly more expensive than older drugs such as haloperidol, sulpiride and perphenazine.

The one-year CUtLASS 1 study looked at 227 patients with schizophrenia who required a change in their treatment, either because of a lack of efficacy or side effects, and assessed whether first-generation medicines performed better than their more recently-introduced rivals in terms of patients’ quality-of-life.

At the end of the year’s follow-up, there was no evidence that second-generation antipsychotics were better than first-generation drugs in quality-of-life scores, and in fact there was a trend towards greater improvements with the older drugs. The patients reported no clear reference for either drug group, and the associated costs of care were similar.

The results have been published in the October edition of the American Medical Association’s Archives of General Psychiatry.

An article accompanying the study, authored by Robert Rosenheck of Yale University’s department of psychiatry, warned against a knee-jerk reaction to the findings, at least in the USA. The medical community should take the findings as the start of the debate, and avoid rushing into any wholesale policy changes.

But this is not the first time the possibility that newer is not necessarily better in schizophrenia drug therapy has been mooted.

Last year, a $43 million study funded the US government reported preliminary findings which suggested that the 40-year-old perphenazine was as effective as second-generation antipsychotics in treating schizophrenia, without imposing a greater burden on patients in terms of side effects.

“Overall, the results of these US studies are in line with the data we present from England,” said the authors of CUtLASS 1.

The principal investigator of CATIE, Dr Jeffrey Lieberman, concurs with this view. In an editorial published in AGP, he said the new data supports the view that “although many effective antipsychotics have been introduced in the wake of chlorpromazine, the pace of real progress through drug development and innovation has been arduous and slow.”