Zyprexa
(olanzapine)
Zyprexa (olanzapine) is manufactured by Eli Lilly and Company. It is a new
"atypical" antipsychotic medication that received FDA approval for
the treatment of schizophrenia in September 1996.
How Zyprexa Works
Researchers and clinical psychopharmacologists do not fully know what causes
schizophrenia. It is known, however, that several neurotransmitters in the
brain are altered in persons with schizophrenia. Zyprexa works to reduce
symptoms of schizophrenia by blocking various serotonin and dopamine receptors.
It blocks the serotonin (5HT2A) receptor more potently than the dopamine (D2)
receptor. In animal studies, Zyprexa is more potent at blocking serotonin and
dopamine than Clozaril. Animal and
human studies, however, indicate that Zyprexa may have a greater risk of
causing extrapyramidal side effects than Clozaril. Extrapyramidal side effects
include slowing of voluntary movement, expressionless face, rigidity and tremor
of arms and head, abnormal toxicity of muscle tissues, and restlessness.
Zyprexa Dosage
Oral doses of 10 mg daily have been effective for most patients in the
treatment of schizophrenia. Zyprexa can be dosed once a day at bedtime. This is
an advantage over Clozaril which needs to be dosed two or more times a day in
most patients. Zyprexa is available by prescription from your pharmacy in 5.0
mg, 7.5 mg and 10 mg tablets. 10 mg has been an effective starting dose in most
patients.
How is Zyprexa different from Clozaril?
Zyprexa differs from Clozaril in side effects. Zyprexa does not cause
seizures or agranulocytosis, a serious deficiency of a type of white blood
cells that could be fatal. Although Clozaril works very well to treat
schizophrenia, it requires a weekly blood draw and weekly prescription refills
because of the monitoring for agranulocytosis. Weekly blood drawing and refills
are not necessary with Zyprexa. Zyprexa also differs from Clozaril in that it
does not cause excessive drooling. Zyprexa may produce more extrapyramidal side
effects (tremor, akathisia, and muscle stiffness) than Clozaril, however.
Zyprexa has not been directly compared to Clozaril in clinical studies in
patients, so it is not now known which drug will be better for certain patients
with schizophrenia.
Side Effects of Zyprexa
Older antipsychotic medications have been difficult for patients to continue
to take because they cause side effects like weight gain, fatigue, stiff body
movement, and blurred vision. Newer antipsychotics like Zyprexa do not cause as
much blurred vision or dryness of the mouth, or as frequent stiff body
movements.
Administration
Zyprexa is available from your pharmacy as oral tablets. The strengths
available are 5 mg, 7.5 mg and 10 mg tablets. The drug is to be taken orally.
Risperdal ~
Clozaril ~ Zyprexa ~
Seroquel ~
Geodon
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For more info on mental illness:
NAMI - National Alliance for the Mentally Ill
703-524-7600 / NAMI HelpLine: 1-800-950-NAMI
www.nami.org
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