Olanzapine – What Do You Need To Know?

Olanzapine is a drug that belongs to the family of atypical antipsychotics. Doctors prescribe it for the treatment of schizophrenia and also for the treatment of depressive crisis related to bipolar disorder and manic episodes.

The pharmaceutical company Eli Lilly and Company was first responsible for the production and distribution of Olanzapine preparations. However, their patent for this drug expired in 2011. So it is now a generic drug and available all over the world.

Learn more about schizophrenia

Schizophrenia is a chronic psychiatric disorder characterized by distorted thoughts, hallucinations and even delusions. These three symptoms are clinically known as ‘positive’ symptoms. However, a patient may also suffer from what doctors call “negative” symptoms. For example, some of these are:

• Social isolation
• Apathy
• Decreased emotional response

As for the causes that trigger schizophrenia, some people are predisposed to this condition due to a range of factors. Some of the key factors include:

• Biochemical changes in the brain. People with this disease usually have abnormal levels of dopamine and serotonin in the brain.
• Genetic factors. The presence of this disease in a parent or other family member increases the risk of it in a child.
• Problems during pregnancy. Certain complications such as anoxia along with certain infections and trauma during this time can affect a baby. Unfortunately, it often leads to the onset of this mental illness and other problems.

Structure and mechanism of action of Olanzapine

This antipsychotic has a chemical structure similar to drugs such as benzodiazepines. In particular, it is structurally related to quetiapine and clozapine.

• Its antipsychotic activity is due to its interaction with serotonin receptors. More specifically, it blocks the 5-HT ₂ receptors in the brain.
• In addition, it also interacts with dopamine D1 and D2 receptors, although moderately.
• It also has an affinity for muscarinic cholinergic receptors, alpha-adrenergic receptors and histamine H1.

• Finally, it is also worth mentioning that a long-acting formula of this drug is also available.

Due to all these interactions, it can cause some adverse effects. We will discuss them in more detail below. Olanzapine can significantly improve both the positive and negative symptoms of schizophrenia due to its high affinity for these receptors.

Pharmacokinetics – How Does the Body Process Olanzapine?

Pharmacokinetics includes the absorption, distribution, metabolism and elimination processes that a drug undergoes after administration. In this sense, Olanzapine is rapidly absorbed after oral intake.

Once absorbed, it reaches maximum plasma concentrations after 6 hours. Keep in mind that the presence of food does not affect absorption, which is not the case with all medicines.

The bioavailability, the maximum concentration of the drug in the blood available at the time of administration, is not very high.

This is due to a strong first-pass effect. Thus, only 40% of the administered dose reaches the systemic circulation. Metabolism, the series of chemical reactions that a drug undergoes in the body to become more soluble and thus facilitate its elimination, takes place in the liver.

Once metabolized, the resulting substances, known as metabolites, may or may not cause an effect on the body. In this case, the metabolites resulting from the chemical reactions that Olanzapine undergoes have no pharmacological activity.

After metabolization, both the metabolites and the resulting drug leave the body. In the case of Olanzapine, 30% leaves the body through the urine and about 55% through the faeces.

Side Effects of Olanzapine

Finally, we would like to discuss the side effects that this drug can cause. The most common side effects of this drug include:

• Weight gain
• drowsiness
• Increase in prolactin levels
• Increase in cholesterol, glucose and triglyceride levels
• Dizziness
• Orthostatic hypotension
• Constipation

• Akathisia and Dyskinesia

Conclusion

Olanzapine is a commonly used drug in the treatment of schizophrenia. Due to its powerful effects on the body, it is only available with a medical prescription. Therefore, you should only use it if prescribed by your doctor. Always follow his or her instructions and ask any questions if necessary.