Olanza

Olanzapine is an antipsychotic agent and has affinities for serotonin 5HT2A/2C, 5HT3, 5HT6; dopamine D1, D2, D3, D4, D5; cholinergic muscarinic receptors M1-M5; α1 adrenergic; and histamine H1 receptors. The mechanism of action of Olanzapine, as with other drugs having efficacy in schizophrenia, is unknown. However, it has been proposed that this drug’s efficacy in schizophrenia is mediated through a combination of dopamine and serotonin type 2 (5HT2) antagonism. Olanzapine is well absorbed after oral administration, reaching peak plasma concentrations within 5 to 8 hours. The absorption is not affected by food. Olanzapine is not mutagenic or clastogenic as well as not carcinogenic.

Olanzapine may antagonize the effects of levodopa and dopamine agonists. Drugs that induce CYP1A2 or glucoronyl transferase enzymes e.g, Omeprazole and Rifampicin, may increase Olanzapine clearance. Inhibitors of CYP1A2 may potentially inhibit Olanzapine elimination. Carbamazepine may increase the clearance of Olanzapine. Concomitant administration of activated charcoal reduces the oral bioavailability of Olanzapine by 50-60%. Caution should be taken when Olanzapine is administered with centrally acting drugs and alcohol.

Very common undesirable effects are somnolence and weight gain. Besides increased appetite, elevated glucose levels, elevated triglyceride levels, dizziness, akathisia, Parkinson’s disease, dyskinesia, orthostatic hypotension, mild and transient anticholinergic effects including constipation and dry mouth, asthenia, edema and photosensitivity reaction etc. may be observed.

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.

Olanzapine should be used cautiously in patients who have a history of seizures or have conditions associated with seizures. Olanzapine should be used cautiously 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 using hepatotoxic medicines, centrally acting drug and medicines know to increase QT interval, especially in the elderly. Patients should be cautioned about operating hazardous machinery, including motor vehicles.

Children: Olanzapine has not been studied in subjects under 18 years of age.

Elderly patients (age 65 and over): starting dose 5 mg/day

Patients with hepatic, renal impairment: starting dose 5 mg/day

Atypical neuroleptic drugs

Keep below 30°C temperature, away from light & moisture. Keep out of the reach of children.