TORONTO - The newest treatment in the battle against schizophrenia is a relative of clozapine, and may have fewer side effects.
Olanzapine, just approved for use in Canada, the U.S. and the U.K., has a similar molecular structure to clozapine, treats both positive and negative symptoms, and may be useful in the full spectrum of schizophrenic patients, said Dr. Barry Jones, associate vice-president for research and development for Eli Lilly Canada.
"Olanzapine is third in the line of so-called novel compounds," said Dr. Gary Remington, director of the medication assessment program for schizophrenia at the Clarke Institute of Psychiatry.
Clozapine was the first to come out, but patients have to undergo weekly blood monitoring. Risperidone was the second, and now olanzapine.
There isn't enough data available to be able to say whether olanzapine is better or the same as risperidone, Dr. Remington said.
Eventually, as new drugs become safer and more effective they may begin to be used as first line treatment, he said. Currently, drugs such as haloperidol are used first.
The new drug will be marketed at a price lower than clozapine, but will cost more than haloperidol, Dr. Jones said. "It will cost about the same as risperidone," he said.
The new drug has been tested on close to 3,000 schizophrenia patients around the world, mostly for acute treatment of the disorder.
A few hundred patients have been on the drug for two to four years, and so far the safety profile looks good, he said.
Many studies have been for dosing and safety, as well as placebo-controlled trials. Further studies comparing the drug to other ones currently used are in the works.
But like other drugs for schizophrenia, olanzapine causes some drowsiness, other sleep problems, and in about 10% of patients, causes a temporary rise in liver enzymes. Patients who have, or who are at risk for, liver disease should undergo testing if they are put on the drug, he said.
Copyright © 1996 Maclean Hunter Publishing Limited
Reprinted with permission.
Internet Mental Health (www.mentalhealth.com) copyright © 1995-2011 by Phillip W. Long, M.D.