June 8, 2006

Japan's Otsuka Pharmaceutical has introduced an atypical antipsychotic agent, Abilify, in the country. Abilify was approved for marketing in the U.S. as a treatment for schizophrenia in November 2002, and is currently marketed in more than 45 countries and regions, including Europe.

"For more than half a century, antipsychotics have provided an effective means for the treatment of schizophrenia," said Kunitoshi Kamijima, a professor at the International University of Health and Welfare. "However, both patients and physicians have continued to be distressed by adverse reactions such as muscle rigidity, finger tremors and mask-like facial expressions that are due to extrapyramidal symptoms Clinicians have high expectations for Abilify, with dopamine partial agonist action, which broadens the options for the treatment of schizophrenia."

Abilify works as a partial agonist against dopamine D2 receptors and differs from other antipsychotics in this respect. It has shown inhibitory action when large amounts of dopamine are released in the brain and stimulatory action when only small amounts of dopamine are released. Because of this mechanism of action, the drug is known as a dopamine system stabilizer, meaning that it improves both positive and negative symptoms of schizophrenia considered to be caused by dopamine abnormalities.