Study Finds Old Antipsychotic Drugs Similar to New Drugs

By Meredith Murray

A study conducted recently to compare drugs for treating schizophrenia showed that perphenazine, an older drug, was just as effective at treating the disorder as many of the newer, more costly medications.

The study also showed that olanzapine, one of the newer drugs, was slightly more effective than the other four medications tested, but it also had the greatest chances to cause side effects such as obesity and metabolic disorders.

Schizophrenia affects roughly 3.2 million Americans, and causes paranoid delusions and hallucinations. Antipsychotics were introduced in the 1950s to treat such symptoms, by blocking a protein in the brain called the dopamine D2 receptor. However, the first drugs produced - including perphenazine - caused side effects like tremors, rigidity, muscle restlessness and involuntary limb movements. A second wave of drugs called "atypicals" were introduced in the 1990s, which were thought to cause fewer side effects.

Over 90 percent of antipsychotics prescribed to people with schizophrenia are atypicals. These drugs are much more expensive. High doses of perphenazine cost about $50 per month, whereas the same amount of olanzapine would cost $600.

In 1999, over 1,400 adults enrolled in the federally funded trial at 57 sites across the country. Patients were randomly assigned either perphenazine or one of four newer atypicals: olanzapine (brand name Zyprexa), quetiapine (Seroquel), risperidone (Risperdal) or ziprasidone (Geodon).

The study showed that perphenazine was equally as effective as quetiapine, risperidone and ziprasidone, based on how long patients stayed on the drugs. Perphenazine also did not cause side effects such as movement disorders any more than the other drugs tested.

By the end of the 18-month study, 74 percent of the patients had stopped taking the drug they had been assigned. Although olanzapine was the most successful of the group, 64 percent of the patients taking that drug had switched to another one before the study was completed. In response to those results, Dr. Ken Duckworth, medical director for the National Alliance on Mental Illness, said, "We need to create better treatments and think more creatively about ways to support people in taking medicines that may help them."

The study's findings may help doctors decide which drug to prescribe first for a patient. Researchers said that the data collected would be used to examine the cost-effectiveness of the drugs and their effect on cognitive abilities and quality-of-life issues.