In a new study involving more than 1,400 people, researchers funded by the National Institute of Mental Health concluded that a mix of four new drugs used to treat schizophrenia had a comparable effect to a long-standing generic in the category. Only one of the new drugs appeared to be modestly better than the others but was also linked to weight gain and unwelcome metabolic changes.
The NIMH wanted to learn how perphenazine, a generic drug available since the 1950s, stacked up against olanzapine, quetiapine, risperidone and ziprasidone, newer drugs that cost 10 times as much as the generic medication.
"Taken as a whole," researchers reported, "the newer medications have no substantial advantage over the older medication used in this study. An important issue still to be considered is individual differences in patient response to these drugs."
And there were a high number of side effects reported. Three-quarters of the patients involved switched medications in the study, complaining of side effects like rigidity, stiff movements, tremor, and muscle restlessness. But patients taking the generic drug were just as likely to tolerate it as three other new drugs in the study.
"The patients started on olanzapine were less likely to be hospitalized for a psychotic relapse and tended to stay on the medication longer than patients taking other medications. However, patients on olanzapine also experienced substantially more weight gain and metabolic changes associated with an increased risk of diabetes than those study participants taking the other drugs."
Scientists involved in the study did note an important caveat, though.
"There is considerable variation in the therapeutic and side effects of antipsychotic medications. Doctors and patients must carefully evaluate the tradeoffs between efficacy and side effects in choosing an appropriate medication. What works for one person may not work for another," said Jeffrey Lieberman, M.D., CATIE's Principal Investigator and Chair of The Department of Psychiatry, Columbia University and Director of the New York State Psychiatric Institute.
That distinction was seized on by advocates of the National Mental Health Association.
"Antipsychotic medications are a critical component of care for many people with schizophrenia," said Michael Faenza, MSSW, NMHA president and CEO. "No two people respond the same to a given treatment. And without a complete range of treatment options valued by consumers and clinicians, people with mental illnesses suffer needlessly. CATIE confirms the need for this broad access and drives home the role of medications in the treatment continuum."
The NMHA fears that doctors may be less likely to prescribe the newer, more expensive drugs because of the study published in the New England Journal of Medicine. And, in fact, several Medicaid programs have already required physicians to stick with generics in treating schizophrenia. Given the new study just out, others are likely to follow their lead.
John Carroll is the editor of FierceBiotech.