COMPOSITION:
Each film coated tablet contains 5 or 10mg Olanzapine.
MECHANISM OF ACTION:
Olan-Prexa is an antipsychotic agent that demonstrates a broad pharmacologic profile across a number of receptor systems. Olan-Prexa exhibited a range of receptor affinities for serotonin 5-HT2A/2C, 5-HT3, 5-HT6, dopamine D1, D2, D3, D4, D5, cholinergic muscarinic receptors M1-M5, α1 adrenergic, and histamine H1 receptors. Electrophysiological studies demonstrated that olanzapine selectively reduced the firing of mesolimbic A10 dopaminergic neurons, while having little effect on the striatal A9 pathways involved in motor function.
INDICATIONS:
Olan-Prexa is indicated for the treatment of schizophrenia, acute manic episodes and bipolar disorder.
DOSAGE:
Children:
It has not been studied in subjects under 18 years of age.
Adults:
- Schizophrenia: The recommended starting dose is 10mg administered as a single daily dose without regard to meals. Daily dosage may subsequently be adjusted on the basis of individual clinical status within the range of 5 – 20mg daily. An increase to a dose greater than the routine therapeutic dose of 10mg daily, to a dose of 15mg daily or greater, is recommended only after appropriate clinical reassessment.
- Mania: The recommended starting dose is 10 – 15mg/day.
Elderly:
A lower starting dose of 5mg daily is not routinely indicated but should be considered for those 65th and over when clinical factors warrant.
Patients with Renal and/or Hepatic Impairment: A lower starting dose 5mg should be considered for such patients. In cases of moderate hepatic insufficiency (cirrhosis), the starting dose should be 5mg, and only increased with caution.
CONTRAINDICATIONS:
It is contraindication in patients with a known hypersensitivity to the product.
SIDE EFFECTS:
The only frequent undesirable effects associated with the use of the drug were somnolence and weight gain. Weight gain was related to a lower pre-treatment body mass and initial starting dose of 15mg or greater. Occasional undesirable effects associated with the use of olanzapine included, increased appetite, orthostatic hypotension, and mild, transient anticholinergic effects, including constipation and dry mouth. Transient, asymptomatic elevations of hepatic transaminases, ALT, AST have been seen occasionally, especially in early treatment. Olanzapine-treated patients had a lower incidence of parkinsonism, akathisia and dystonia compared with titrated doses of haloperidol. Seizures have been reported to occur rarely in patients treated with olanzapine. In most of these cases, a history of seizures or risk factors for seizures were reported.
DRUG INTERACTIONS:
Single doses of antacid (aluminum, magnesium, or cimetidine) did not affect the oral bioavailability of the drug. However, the concomitant administration of activated charcoal reduced the oral bioavailability of the drug by 50 to 60%. The metabolism of olanzepine may induced by smoking and carbamazepine, which may lead to reduce olanzepine concentration, only slight to moderate increase in olanzepine clearance has been observed. The pharmacokinetics of theophylline, which is metabolized by (P450-1A2), is not altered by the drug. No inhibition of the metabolism of imipramine /desipramin, warfarin, theophylline, or diazepam was evident. The drug showed no interaction when co-administered with lithium or biperiden.
PRECAUTIONS:
- Caution is advised when prescribing for patients with prostatic hypertrophy, or paralytic ileus and related conditions.
- Caution should be exercised in patients with elevated ALT and/or AST, in patients with signs and symptoms of hepatic impairment.
- Caution should be exercised in patients with low leucocyte and/or neutrophil counts for any reason, in patients with a history of drug induced bone marrow depression/toxicity, in patients with bone marrow depression caused by concomitant illness, radiation therapy or chemotherapy and in patients with hypereosinophilic conditions or with myeloproliferative disease.
- Caution should be used when the drug is taken in combination with other centrally acting drugs and alcohol. As it exhibits dopamine antagonism.
- Postural hypotension was infrequently observed in the elderly. As with other antipsychotics, it is recommended that blood pressure is measured periodically in patients over 65 years.
- Caution should be exercised when the drug is prescribed with drugs known to increase QTC interval, especially in the elderly.
- Patients should be cautioned about operating hazardous machinery, including motor vehicles, because the drug may cause somnolence.
USE IN PREGNANCY OR LACTATION:
This drug could be used in pregnancy only if the potential benefit justifies the potential risk to the fetus (C category). Patient should be advised not to breast feed an infant if they are taking the drug.