| GENERIC NAME: olanzapine
BRAND NAME: Zyprexa
DRUG CLASS AND MECHANISM: Olanzapine is a medication
that is used to treat psychoses including schizophrenia and acute manic
episodes associated with bipolar I disorder. Olanzapine is similar in
chemical structure and in mechanism of action to clozapine (Clozaril).
Like clozapine, olanzapine works by blocking receptors on the nerves of
the brain for several neurotransmitters (chemicals that nerves use to
communicate with each other). It binds to alpha-1, dopamine, histamine
H-1, muscarinic, and serotonin type 2 (5-HT2) receptors. Olanzapine was
approved by the FDA in 1996.
PREPARATIONS: Tablets of 5, 7.5, and 10 mg
STORAGE: Tablets should be kept at room temperature,
15-30°C (59-86°F).
PRESCRIBED FOR: Olanzapine is used for treating patients
with schizophrenia and manic episodes associated with bipolar I disorder.
It also is used as maintenance therapy for bipolar disorder.
DOSING: Olanzapine is usually given once daily, with
the dose often adjusted upward until an optimal dose is found. It may
be taken with or without food. Tobacco smokers may need higher doses.
DRUG INTERACTIONS: Reduced or increased blood levels:
Carbamazepine (Tegretol) can significantly reduce blood concentrations
of olanzapine, possibly necessitating higher doses of olanzapine. Other
drugs that also may reduce blood level of olanzapine are omeprazole (Prilosec)
and rifampin. Cimetidine (Tagamet), ciprofloxacin (Cipro), diltiazem (Cardizem;
Dilacor; Tiazac), erythromycin, and fluvoxamine (Luvox) may have the opposite
effect, that is, they may increase blood levels, and the dose of olanzapine
possibly may need to be reduced.
Low blood pressure: Olanzapine can cause orthostatic hypotension, a drop
in blood pressure upon rising that may cause dizziness. Taking olanzapine
with either diazepam (Valium), another related benzodiazepine or ethanol
can exaggerate the orthostatic hypotension caused by olanzapine.
PREGNANCY: There are no adequate studies of olanzapine
in pregnant women. Some studies in animals suggest no important effects
on the fetus, whereas others suggest an ill-effect. Olanzapine can be
used in pregnancy if the physician feels that it is necessary.
NURSING MOTHERS: It is not known if olanzapine is secreted
in breast milk in humans, but animal studies show that olanzapine is excreted
into breast milk. Therefore, it is recommended that olanzapine not be
used in nursing mothers.
SIDE EFFECTS: The most common side effects seen with
olanzapine are akathisia (a feeling of an inability to sit still), constipation,
dizziness, drowsiness, objectionable behavior, orthostatic hypotension
(see DRUG INTERACTIONS), and weight gain. Each of these side effects may
occur in 1 in 20 persons.
Disorders of movement: Extrapyramidal effects (sudden, often jerky, involuntary
motions of the head, neck, arms, body, or eyes) may occur with use of
olanzapine. Tardive dyskinesia (involuntary movements of the mouth, tongue,
jaw, or eyelids) may occur in 1 in 100 patients receiving olanzapine.
Some cases can be irreversible. The likelihood of developing tardive dyskinesia
increases with prolonged treatment.
There may be an increased risk of increased blood sugar levels and diabetes
with olanzapine as well as the other antipsychotic medications in its
class. Patients should be tested during treatment for elevated blood-sugars.
Additionally, persons with risk factors for diabetes, including obesity
or a family history of diabetes, should have their fasting levels of blood
sugar tested before starting treatment and periodically throughout treatment
to detect the onset of diabetes. Any patient developing symptoms that
suggest diabetes during treatment should be tested for diabetes.
Caution! Before starting
to take this medicine, it is vital that you should consult your doctor!
Do not use it on your own initiative, without medical advice.
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