Health Centres - Zyprexa (olanzapine)
How does it work?
Zyprexa tablets, velotabs and injection all contain the active ingredient olanzapine, which is a type of medicine known as an atypical antipsychotic.
Olanzapine works in the brain, where it affects various neurotransmitters, in particular serotonin (5HT) and dopamine. Neurotransmitters are chemicals that are stored in nerve cells and are involved in transmitting messages between the nerve cells.
Dopamine and serotonin are neurotransmitters known to be involved in regulating mood and behaviour, amongst other things. Psychotic illness is considered to be caused by disturbances in the activity of neurotransmitters (mainly dopamine) in the brain. Schizophrenia is known to be associated with an overactivity of dopamine in the brain, and this may be associated with the delusions and hallucinations that are a feature of this disease.
Olanzapine works by blocking the receptors in the brain that dopamine acts on. This prevents the excessive activity of dopamine and helps to control schizophrenia.
Schizophrenic patients may experience 'positive symptoms' (such as hallucinations, disturbances of thought, hostility) and/or 'negative symptoms' (such as lack of emotion and social isolation). Olanzapine is effective in relieving both positive and negative symptoms of schizophrenia, whereas the conventional antipsychotics are usually less effective against the negative symptoms.
Olanzapine is also used to treat moderate to severe episodes of mania in people with bipolar affective disorder (manic depression). In people whose manic episode is controlled with olanzapine, the medicine may also be used long-term as a mood stabiliser to prevent further manic and depressive episodes of bipolar disorder.
Zyprexa injection is used when rapid control of agitation and disturbed behaviours is needed for people with schizophrenia or a manic episode. Once behaviour has been controlled, the treatment is usually switched to oral treatment with Zyprexa tablets or Zyprexa velotabs. Zyprexa velotabs are tablets that are designed to dissolve on the tongue and be swallowed with the saliva, without the need for water.
What is it used for?
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Schizophrenia.
- Moderate to severe manic episodes of manic depression.
- Stabilising mood to prevent episodes of mania or depression in people with bipolar affective disorder whose manic episode has responded to olanzapine treatment.
Warning!
- Zyprexa velotabs should be placed in the mouth where they will rapidly dissolve in your saliva for easy swallowing. The velotabs are fragile, so should be taken as soon as you have opened the blister; alternatively they can be dissolved in a glass of water, orange juice, apple juice, milk or coffee before taking.
- This medicine may cause drowsiness or dizziness. If affected do not drive or operate machinery.

