Antipsychotic Medications Anti-psychotic Drugs olanzapine, Zyprexa
Antipsychotic: olanzapine, Zyprexa
Generic Name: olanzapine
Brand Name(s): Zyprexa
Common Use: Antipsychotic
Antipsychotic Agent
Pharmacodynamic Properties: Olanzapine,
a thienobenzodiazepine, is an antipsychotic agent, displaying
high receptor affinity binding in vitro at serotonin,
dopamine, muscarinic, adrenergic alpha1, and histamine
receptors.
Olanzapine is indicated for the acute
and maintenance treatment of bipolar disorder, schizophrenia
and related psychotic disorders. In controlled clinical
trials, olanzapine was found to improve both positive
and negative symptoms.
Olanzapine has been shown to be effective
in maintaining clinical improvement during one year
of continuation therapy in patients who had shown an
initial treatment response.
Contraindications
Olanzapine is contraindicated in those
patients with a known hypersensitivity to the drug or
the excipients of the product.
Adverse Reactions
The stated frequencies of adverse events
represent the proportion of individuals who experienced
at least once a treatment emergent adverse event of
the type listed. An event was considered treatment-emergent
if it occurred for the first time or worsened while
receiving therapy following baseline evaluation. It
is important to emphasize that although the events were
reported during therapy. They were not necessarily caused
by the therapy.
The prescriber should be aware that the
figures in the tables and tabulations cannot be used
to predict the incidence of side effects in the course
of usual medical practice where patient characteristics
and other factors differ from those that prevailed in
the clinical trials. Similarly, the cited frequencies
cannot be compared with figures obtained from other
clinical investigations involving different treatments,
uses, and investigators. The figures cited however do
provide the prescribing physician with some basis for
estimating the relative contribution of drug and nondnug
factors to the side effect incidence in the populations
studied.
Therapy with olanzapine more common side
effects were, dizziness, constipation, ALT (SGPT) increased,
weight gain, akathisia, and postural hypotension.
Adverse Events Associated with Discontinuation:
There was no statistically significant difference in
rates of discontinuation of olanzapine or placebo attributed
to adverse events.
The following were common adverse reactions
that may be related to olanzapine:
Constipation, Dry mouth, SGPT increased, Weight gain,
Peripheral Edema, Somnolence, Agitation, Dizziness,
Personality disorder, Akathisiat, Amnesia,
Euphoriam, Rhinitis, Fungal dermatitis, Mensrual Disorder,
Abnormal dreams.
Overdose
Experience with olanzapine in overdosage
is limited. In clinical trials, accidental or intentional
acute overdosage of olanzapine was identified in 67
patients. In the patient taking the largest identified
amount, 300 mg, the only symptoms reported were drowsiness
and slurred speech. In the limited number of patients
who were evaluated in hospitals, including the patient
taking 300 mg there were no observations indicating
an adverse change in laboratory analyses or ECG. Vital
signs were usually within normal limits following overdoses.
There is no specific antidote to olanzapine;
therefore, appropriate supportive measures should be
initiated. The possibility of multiple drug involvement
should be considered In case of acute overdosage establish
and maintain an airway and ensure adequate oxygenation
and ventilation. The use of activated charcoal for overdose
should be considered because the concomitant administration
of activated charcoal was shown to reduce the oral bioavailability
of olanzapine by 50% to 60%.Gastric lavage (after intubation,
if patient is unconscious) may also be considered.
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