What is Zyprexa (Olanzapine)?
Zyprexa is an antipsychotic (neuroleptic) drug with a wide range pharmacological effects. Zyprexa has an antipsychotic, anxiolytic and potentiating effect.
The drug reduces symptoms of psychiatric disorders, psychosis has a smoothing effect on negative mental symptoms. Zyprexa is capable of reducing the intensity of emotions, aggression, impulsive behavior. Olanzapine (a generic name for Zyprexa) is able to decrease excitement.
What is Zyprexa is used for?
Zyprexa is prescribed in the following cases:
- Schizophrenia: treatment of exacerbations, maintenance and long-term preventive treatment of schizophrenia and other psychotic disorders with severe productive (including delusions, hallucinations, automatism) and/or negative (including emotional flattening, decreased social activity, impoverishment of speech ) symptoms, as well as the concomitant affective disorders;
- Bipolar affective disorder: olanzapine as monotherapy or in combination with lithium or valproate is indicated to treat acute manic or mixed episodes in bipolar disorder with/without psychotic symptoms and with/without rapid phase change. Olanzapine is used to prevent relapses in patients with bipolar disorder, who got positive results using Zyprexa to treat manic phase.
Zyprexa is used in combination with fluoxetine for treatment of depression associated with bipolar disorder.
Avoid using Zyprexa if you are hypersensitive to Olanzapine and other components of the drug.
Take Zyprexa with caution in case of:
- History of seizures;
- Prostatic hypertrophy with severe symptoms;
- Paralytic nature ileus;
- Inhibition of bone marrow hematopoiesis;
- Angle-closure glaucoma;
- Myeloproliferative pathologies.
The recommended initial dosage of Zyprexa in case of schizophrenia and related psychotic disorders is 10 mg 1 time a day.
Take the drug with or without food, washing down with a glass of water. Usual therapeutic dosages are in a range of 5-20 mg a day. Your daily dosage should be adjusted individually depending on your health condition. It is recommended to increase the standard initial dosage of is 10 mg of Zyprexa a day only after consultation with your doctor.
In a case of an acute mania of bipolar disorder, the recommended starting dosage is 15 mg of Zyprexa 1 time a day. Therapeutic Olanzapine dosage varies in a range of 5-20 mg a day. Your daily dosage should be set individually depending on your clinical condition. Increase your standard dosage of 15 mg of Zyprexa a day only after clinical examination by your doctor. Increase your dosage gradually, with at least 24 hours intervals.
Elderly patients, as well as people with renal failure or insufficiency, moderate to severe liver function disorders, should start with an initial dosage of 5 mg Zyprexa a day.
Most common symptoms of Zyprexa overdose are tachycardia, agitation or aggression, articulation disorder, various extrapyramidal disorder and various consciousness disorders (from sedation to coma). Other clinically relevant effects of olanzapine overdose include delirium, seizures, neuroleptic malignant syndrome, respiratory depression, aspiration, hypertension or hypotension, cardiac arrhythmias and heart failure. The minimum dosage for acute overdose was 450 mg, the maximum dosage in case of Zyprexa overdose with favorable outcome (survival) was 1500 mg.
If you experience one or several symptoms of overdose with Zyprexa, contact your doctor or call the ambulance.
Inducers or inhibitors of cytochrome P450 isoenzymes can influence the metabolism of olanzapine.
Olanzapine clearance is increased in smokers.
CYP1A2 inhibitors may decrease the clearance of olanzapine.
Clinical trials have shown that a single injection of Olanzapine during therapy with the following medications has not influenced on their metabolism: imipramine or its metabolites desipramine, theophylline or diazepam.
There were no signs of drug interactions of olanzapine in combination with lithium.
Olanzapine does not interact with alcohol. However, simultaneous intake of alcohol and Zyprexa may increase pharmacological effects of olanzapine, such as sedation.
A single dosage of aluminum and magnesium antacid or cimetidine did not affect the bioavailability of olanzapine by ingestion. Simultaneous intake of activated charcoal reduces the bioavailability of olanzapine by 50-60%.
Fluoxetine can interact with Zyprexa in a case of their simultaneous intake. It is usually not recommended to change the dosage of Zyprexa when it is used in combination with fluoxetine.
In vitro studies using human liver microsomes showed that olanzapine significantly suppresses the formation of valproate glucuronide. Valproate has little effect on the metabolism of olanzapine in vitro. Therefore, a clinically significant interaction between olanzapine and valproate is limited.
According to in vitro studies using human liver microsomes, olanzapine has a very low potential to inhibit the activity of these cytochrome P450 isoenzymes.
Zyprexa during pregnancy and breastfeeding
Consult with your doctor, if you are pregnant or plan pregnancy before taking Zyprexa. Due to the limited experience of using Zyprexa by pregnant women, take the drug only in cases, where the potential treatment benefits for a mother are much higher than a potential risk to a fetus.
Studies show that olanzapine penetrates into breast milk. That is why it is not recommended to use Zyprexa during breastfeeding.
When planned and ensuing pregnancy during therapy with olanzapine patients should be advised to seek medical advice. Due to the limited experience of the use of olanzapine in pregnancy in human use of the drug is possible only in cases where the potential benefits of therapy for the mother is much higher than the potential risk to the fetus.
The study found that olanzapine was excreted in breast milk. If necessary, use during lactation should stop breastfeeding.
Zyprexa side effects
Treatment with Zyprexa may be accompanied by the following side effects:
- Diabetic coma;
- Weight gain;
- Increased appetite;
- Dry mouth;
- Gait disorders;
- Peripheral edema;
- Skin rash;
- Activation of liver enzymes;
- Orthostatic hypotension.
Using antipsychotic drugs, including Zyprexa, may develop neuroleptic malignant syndrome, which can be potentially lethal. The clinical symptoms of this syndrome include a significant increase in body temperature, muscle rigidity, altered mental state, and autonomic disorders (unstable pulse or blood pressure, tachycardia, cardiac arrhythmias, sweating). Additional signs may include increased levels of CPK, myoglobinuria and acute renal failure. Clinical manifestations of neuroleptic malignant syndrome or a significant increase in body temperature with no other symptoms of this syndrome require canceling all antipsychotics, including Zyprexa.
Comparative studies lasting more than 6 weeks showed, that Zyprexa is significantly less accompanied by the development of dyskinesia, requiring medical help, than using of haloperidol. However, there is a risk of tardive dyskinesia after long-term treatment with neuroleptics. Reduce Zyprexa dosage or stop taking the drug in case of tardive dyskinesia symptoms. The symptoms of tardive dyskinesia can be observed even after you stop taking the drug.
Take Zyprexa with caution, if you suffer from liver failure or if you are taking potentially hepatotoxic drugs. Your doctor will help you to adjust your Zyprexa dosage in order not to harm your health condition.
Take Olanzapine with caution in case of seizures in history or if you were exposed to factors, which reduce seizure threshold.
Be cautious taking the drug in case of reduced number of white blood cells and / or neutrophils, due to various reasons; with symptoms of depression / toxic disorders of the bone marrow under the influence of drugs history; with inhibition of bone marrow function due to concomitant illness, radiation therapy or chemotherapy in history; with hypereosinophilic or myeloproliferative disease.
Clinical trials showed, that Olanzapine therapy is rarely accompanied by adverse effects associated with an anticholinergic activity of the drug. However, clinical experience with olanzapine in patients with concomitant illness is limited. Therefore, take Zyprexa with caution in case of clinically significant prostatic hypertrophy, paralytic ileus, narrow-angle glaucoma and related conditions.
In in vitro conditions olanzapine exhibits antagonism against dopamine and, like other neuroleptics can theoretically suppress the action of levodopa and dopamine agonists.
Take Zyprexa with caution in combination with other centrally acting drugs and ethanol.
Be cautious driving a car or working with mechanical equipment while taking Zyprexa, as the drug may cause drowsiness.
Using Zyprexa for children
The safety and efficiency of treating children under 18 years old with Zyprexa have not been studied.