In a recent study involving more than 1,400 people, researchers funded by the National Institute of Mental Health concluded that a mix of four new medications used to treat schizophrenia had a comparable effect to a generic medication that has been a mainstay treatment for decades. Only one of the newer medications appeared to be modestly better than the others, but was also linked to weight gain and unwelcome metabolic changes.
Those results have triggered a renewed debate over the value of comparative drug research studies and fueled anticipation among some patient advocates that state Medicaid programs are likely to cut beneficiaries off from branded anti-psychotics.
The NIMH set out to learn how perphenazine, a generic drug available since the 1950s, stacked up against olanzapine, quetiapine, risperidone, and ziprasidone, newer drugs that cost ten times as much as the generic medication.
"Taken as a whole," researchers reported in the New England Journal of Medicine, "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."
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 they were to tolerate the 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., the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) program's principal investigator, chair of The Department of Psychiatry at 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, 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 and more expensive medications because of the study. And in fact, several Medicaid programs have already required physicians to stick with generics in treating schizophrenia. Given the new results, others are likely to follow their lead.
"NIMH is helping fill a large research void - specifically regarding effectiveness, comparative analysis and side effects of antipsychotic medications," said Faenza. "Such research will ultimately help consumers and clinicians make more informed choices about which treatment is best for each individual. Unfortunately in the meantime, this research void has led to scientifically unsound comparative 'research' that often spurs states and other health care payors to restrict access to many needed treatments for people with mental illnesses, including schizophrenia. The CATIE findings clearly illustrate that when you restrict consumers' choice of antipsychotic medications, you are basically playing clinical roulette."
"The study has vital public health implications because it provides doctors and patients with much-needed information comparing medication treatment options," said NIMH Director Thomas R. Insel, M.D. "It is the largest, longest, and most comprehensive independent trial ever done to examine existing therapies for this disease."
