Generic

Olanzapine

Indications

Olanzapine is used to treat schizophrenia and kindred psychoses in which positive symptoms (such as delusions, hallucinations, disordered thinking, anger, and suspiciousness) and/or negative symptoms (such as flattened affect, emotional and social withdrawal, and speech poverty) are present. Olanzapine is used to treat bipolar disorder’s acute manic or mixed episodes, with or without psychotic characteristics and with or without a rapid cycling course.

Pharmacology

Olanzapine is an antipsychotic drug that binds to serotonin 5HT2A/2C, 5HT3, and 5HT6 receptors, as well as dopamine D1, D2, D3, D4, D5, cholinergic muscarinic receptors M1-M5, 1 adrenergic receptors, and histamine H1 receptors. Olanzapine’s mechanism of action, like that of other anti-schizophrenia medications, is unknown. However, it has been suggested that the drug’s efficacy in schizophrenia is mediated through antagonism of dopamine and serotonin type 2 (5HT2). After oral treatment, olanzapine is rapidly absorbed, reaching peak plasma concentrations in 5 to 8 hours. Food has no effect on the absorption. Olanzapine is not carcinogenic, nor is it mutagenic or clastogenic.

Dosage

Schizophrenia, combination therapy for Mania, Bipolar Disorder: The initial dose is 5-10 mg once daily. Daily dosage may subsequently be adjusted on the basis of individual clinical status within the range of 5-20 mg daily. Dosage greater than 10 mg daily only after reassessment. Maximum dose is 20 mg daily.

Monotherapy for Mania: Initially 15 mg once daily. Daily dosage may subsequently be adjusted on the basis of individual clinical status within the range of 5-20 mg daily. Dosage greater than 15 mg only after reassessment. Maximum dose is 20 mg daily.

Administration

Olanzapine can be given without regard to meals. Gradual tapering of the dose should be considered while discontinuing Olanzapine.

Interaction

Olanzapine may counteract the effects of dopamine agonists and levodopa. Omeprazole and Rifampicin, for example, may improve Olanzapine elimination by inducing CYP1A2 or glucoronyl transferase enzymes. Olanzapine clearance could be hampered by CYP1A2 inhibitors. Carbamazepine may improve Olanzapine clearance. The oral bioavailability of Olanzapine is reduced by 50-60% when it is given with activated charcoal. When used with centrally acting medications and alcohol, Olanzapine should be used with caution.

Contraindications

Olanzapine is contraindicated in those patients with a known hypersensitivity to any ingredient of the product as well as in patients with known risk for narrow-angle glaucoma.

Side Effects

Somnolence and weight gain are two of the most typical side effects. Aside from increased appetite, elevated glucose levels, elevated triglyceride levels, dizziness, akathisia, Parkinson’s disease, dyskinesia, orthostatic hypotension, and mild and transient anticholinergic effects such as constipation and dry mouth, asthenia, edema, and photosensitivity reaction, mild and transient anticholinergic effects such as constipation and dry mouth, asthenia, edema, and photosensitivity reaction may be observed.

Pregnancy & Lactation

Olanzapine should be used in pregnancy only if the potential benefits justify the potential risk to the foetus. So, patients should be advised to notify their physician if they become pregnant or intend to become pregnant during treatment with Olanzapine. There is no report to show teratogenecity. Patients should not breast feed if they are taking Olanzapine.

Precautions & Warnings

In patients with a history of seizures or diseases linked to seizures, olanzapine should be administered with caution. Olanzapine should be used with caution in patients with low leukocyte and/or neutrophil counts for any reason, drug-induced bone marrow depression/toxicity caused by radiation therapy or chemotherapy, hypereosinophilic conditions, impaired hepatic function, and patients taking hepatotoxic medicines, as well as patients taking centrally acting drugs and medicines known to prolong the QT interval, especially in the elderly. Patients should be warned about operating potentially dangerous machinery, such as automobiles.

Therapeutic Class

Atypical neuroleptic drugs

Storage Conditions

Do not store at temperatures above 30°C. Keep out of children’s reach.

Pharmaceutical Name

General Pharmaceuticals Ltd.