LONDON Costly new antipsychotic drugs are not significantly better than cheaper older ones at treating a first episode of schizophrenia, Dutch researchers said on Friday.
The finding adds to controversy about the benefits of second-generation products like AstraZeneca Plc's Seroquel and Eli Lilly and Co's Zyprexa, which were introduced in the 1990s and are now multibillion-dollar sellers.
Such so-called atypical antipsychotics today account for the lion's share of prescriptions and are purported to be more effective and less likely to cause side-effects, such as stiffness and tremors.
But Rene Kahn of the University Medical Centre in Utrecht and colleagues said they were not necessarily better.
To compare the medicines they did an open randomized trial involving 498 patients aged 18 to 40 years. The participants were given either the old drug haloperidol or one of four higher-dose new drugs -- Seroquel, Zyprexa, Pfizer Inc's Geodon or Sanofi-Aventis SA's Solian.
Over the following 12 months, 63 patients on haloperidol stopped treatment compared to 51 on Seroquel, 32 on Solian, 31 on Geodon and 30 on Zyprexa.
The reductions in all symptoms, however, were about the same for all groups, at around 60 percent, and there were no significant differences between the drugs according to sex, tendencies towards suicide and substance abuse.
The higher continuation rate seen with the newer drugs was encouraging but Kahn, writing in the Lancet medical journal, said "it cannot be concluded that second-generation antipsychotic drugs are more efficacious".
The new report follows earlier critical research, including a U.S. study in December 2006 that found another first-generation antipsychotic drug, perphenazine, was as effective as newer medications.
Robert Rosenheck of the VA Connecticut Health Care System in the United States said in an accompanying Lancet commentary there was "much less, if any, ground for enthusiasm about these costly drugs now than in 2002".
The latest Dutch study received funding from AstraZeneca, Pfizer and Sanofi.
(Reporting by Ben Hirschler)