Olanzapine, also known as Zyprexa®, is a member of a class of medication used predominantly to treat the symptoms of schizophrenia. This medication and other atypical antipsychotic drugs in the thienobenzodiazepine drug family should only be prescribed when absolutely necessary, as the side effects of olanzapine can be very serious in some patients. Although generally used to treat the symptoms of schizophrenia, one of the off-label uses of olanzapine is as an adujunct therapy in the treatment of bipolar disorder. When determining the appropriate initial olanzapine dose to use, adjustments must be made according to the age of the patient. Other factors that can affect the suggested olanzapine dose are whether the patient is debilitated, susceptible to lowered blood pressure reactions, uses cytochrome 4501A2 inhibiting medications, or makes adjustments to his or her smoking habits.
When treating schizophrenia in adults, the standard initial olanzapine dose is between 5 and 10 mg orally taken once per day. The maximum daily dose should not exceed 20 mg, allowing for a maintenance dose of 10 mg may to be taken once per day if needed. Due to the serious risks of olanzipine when administered to elderly patients, increases to a daily dose of 5 mg should be carefully considered. This medication should not be used to treat psychotic symptoms associated with dementia, as one of the risks of olanzapine in these patients is sudden death.
The standard initial dose for the treatment of schizophrenia in pediatric populations is much lower than that for adults. An initial olanzapine dose of 2.5 to 5 mg is recommended for patients between eight and 17 years old, although there has yet been little research into its efficacy. This dose can be increased by 2.5 to 5 mg each week to a target dose of 10mg daily. Daily doses should not exceed 20 mg per day.
For patients who are predisposed to hypotensive episodes, an initial daily dose of 5 mg is recommended. Dosage increases should be administered only with caution. The same dosage recommendations should also be used for debilitated patients.
In addition to dementia, the use of olanzapine is contraindicated in patients with Alzheimer's disease, seizures, liver disease, prostate problems, glaucoma, intestinal disease, breast cancer, low blood pressure or a history of neuroleptic malignant syndrome or stroke. The most common side-effects of olanzapine include weight gain, restlessness, dry mouth, irritability, dizziness, sleep disorder, sedation and constipation. One of the most serious risks of olanzapine, however, is tardive dyskenesia, an involuntary muscle movement disorder. This condition is extremely resistant to treatment. Since higher doses of olanzapine increase the risk of developing this condition, it is important to use the smallest effective dose of the drug.
