How olanzapine works
Olanzapine is a drug from the group of so-called atypical antipsychotics. It has an antipsychotic effect (against psychoses), an antimanic effect (against a strong increase in drive that occurs in phases) and a mood-stabilizing effect, which is why, unlike other antipsychotics, it is approved for the treatment of bipolar disorders.
In the brain and spinal cord (central nervous system), the interaction of various nerve messengers (neurotransmitters) ensures that one feels balanced and can react appropriately to certain situations (such as excitement, joy, fear, etc.). For this purpose, the various messenger substances (such as serotonin and dopamine) are released by nerve cells as needed and later reabsorbed and stored.
Absorption, degradation and excretion
After absorption by mouth (per oral), olanzapine is well absorbed from the intestine into the blood. Degradation occurs in the liver with the involvement of the enzyme CYP1A2. The breakdown products are excreted mainly by the kidney.
When administered into the muscle (intramuscularly) as a depot injection, the drug is gradually released from the formed depot over a longer period of time. However, breakdown and excretion remain identical to absorption by mouth.
When is olanzapine used?
The indications for use (indications) of olanzapine include:
- Schizophrenia
- Manic episode in the context of a bipolar disorder (if the patient responds, olanzapine is also suitable for preventing manic phases)
How olanzapine is used
The active ingredient olanzapine is usually taken in the form of tablets or melting tablets. In acute cases, the active ingredient may also be injected directly into the blood.
In patients who are stably adjusted to olanzapine, the active substance can be injected into the muscle as a depot injection – to avoid taking tablets every day. The injection is then repeated every two or four weeks by the treating physician.
What are the side effects of olanzapine?
Very often, that is, in more than ten percent of those treated, olanzapine causes side effects such as weight gain and drowsiness.
Often (in one to ten percent of those treated), treatment causes changes in blood counts, dizziness, dry mouth, constipation, and lowered blood pressure (especially with rapid changes in position, such as getting up quickly from lying down).
What should be considered when taking olanzapine?
Contraindications
Olanzapine should not be used in:
- narrow-angle glaucoma (form of glaucoma)
Caution is also advised in:
- enlargement of the prostate (prostatic hyperplasia)
- Pyloric stenosis (narrowing in the area of the stomach outlet)
Drug Interactions
Olanzapine may increase the effects of blood pressure medications (e.g., ACE inhibitors, sartans, beta blockers) or sleep medications (e.g., benzodiazepines, antihistamines) taken concomitantly.
Alcohol increases the sedative effects of olanzapine.
Be aware of these interactions especially when driving or operating heavy machinery.
Olanzapine is broken down in the liver primarily by the enzyme CYP1A2. Other drugs that block or induce (increase in activity of) this enzyme may therefore increase or decrease the effect and side effects of olanzapine:
CYP1A2 inhibitors such as fluvoxamine (antidepressant) and ciprofloxacin (antibiotic) may increase olanzapine effects. CYP1A2 inducers such as carbamazepine (epilepsy medication) and tobacco smoke may attenuate olanzapine effects by accelerating the breakdown of the drug.
Trafficability and operation of machines
Together with the doctor, it must then be decided whether active participation in road traffic or the operation of heavy machinery is possible.
Age restrictions
Very little experience is available on the use of olanzapine in children and adolescents. Therefore, treatment should only be administered by very experienced physicians if the individual benefit clearly outweighs the corresponding risk.
Pregnancy and lactation
According to experts, proven alternatives (risperidone, quetiapine) should be used instead of olanzapine during pregnancy. However, if a woman is well adjusted to the active substance (good efficacy with good tolerability), it may continue to be taken during pregnancy.
Olanzapine use during pregnancy may cause adjustment disorders in the newborn shortly after birth. Physicians must pay careful attention to this.
How to obtain medication with olanzapine
Medicines containing olanzapine require a prescription in Germany, Austria, and Switzerland because the success of treatment must be regularly monitored by a doctor. You can therefore only obtain the medication from a pharmacy with a prescription from your doctor.
How long has olanzapine been known?
Olanzapine is a relatively new drug. It was developed from the so-called “classic antipsychotics”, i.e. drugs for mental disorders, and was approved in Germany in 1996.
As a member of the group of “atypical antipsychotics” (second-generation antipsychotics), olanzapine has fewer side effects but can lead to severe weight gain and disturbances in lipid metabolism.
