Zyprexa - olanzapine

What is Zyprexa?

Zyprexa is a medicine that contains the active substance olanzapine. The medicine is available as tablets (white and round: 2.5, 5, 7.5 and 10 mg; blue and oval: 15 mg; pink and oval: 20 mg) and as a powder for solution for injection.

What is Zyprexa used for?

Zyprexa is indicated for the treatment of adults with schizophrenia. Schizophrenia is a mental illness characterized by a range of symptoms, including thought and speech disorders, hallucinations, suspiciousness and delusions. Zyprexa is also effective in maintaining clinical improvement in patients who have responded positively to initial treatment.
The drug is also used to treat moderate to severe manic episodes (particularly high mood) in adults. It can also be used to prevent manic episodes from returning (symptoms returning) in patients with bipolar disorder (a mental illness characterized by alternating manic and depressive phases) in patients who have responded to initial treatment.
Zyprexa is usually taken orally; the solution for injection is indicated for the rapid control of agitation or behavioral disturbances in patients with schizophrenia or manic episode, when oral therapy is not appropriate.
The medicine can only be obtained with a prescription.

How is ZYPREXA used?

The recommended starting dosage for Zyprexa tablets depends on the disease being treated: for schizophrenia and the prevention of manic episodes it is 10 mg per day; for the treatment of manic episodes is 15 mg per day, unless used in combination with other medicines, in which case the starting dose may be 10 mg per day. The dosage should be adjusted according to the patient's response and degree of tolerance of the therapy within a range of 5 to 20 mg per day.
The usual dose for the solution for injection is 10 mg given as a single injection into the
muscle. A second injection of 5 or 10 mg may be given two hours later. The dosage should be reduced in patients over 65 years of age (5 mg per day for tablets and 2.5-5 mg for solution for injection) and in subjects with liver or kidney problems (5 mg per day for both tablets and solution for injection).
In any case, the maximum daily dose of Zyprexa, using the tablets or the solution for injection, is 20 mg.

How does Zyprexa work?

The active substance in Zyprexa, olanzapine, is an antipsychotic drug known as an "atypical" antipsychotic, as it differs from the older antipsychotic drugs available since the 1950s. While its exact mechanism of action is not known, it is nevertheless linked to different receptors present on the surface of nerve cells in the brain. This disrupts the signals transmitted between brain cells through "neurotransmitters" - the chemicals that allow nerve cells to communicate with each other. The beneficial effect of olanzapine is due to its ability to block the receptors for the neurotransmitters 5-hydroxytryptamine (also called serotonin) and dopamine. Since these neurotransmitters are implicated in schizophrenia and bipolar disorder, olanzapine contributes to the normalization of brain activity, reducing the symptoms of these diseases.

How has Zyprexa been studied?

Zyprexa tablets were studied in around 3,000 adults with schizophrenia, where the drug's effectiveness was compared with that of placebo (a substance that has no effect on the body) or haloperidol (another antipsychotic drug). Four studies were conducted, all lasting six weeks; affected patients, however, continued to take the drug for a year or more.
For the treatment of acute manic episodes in adults with bipolar disorder, Zyprexa tablets were compared with placebo, haloperidol or valproate (another drug used in manic episodes) in five studies, including one in patients undergoing also to therapy with other drugs. In the prevention of manic episodes, Zyprexa tablets were studied in 1,162 adults. Their effectiveness was compared with that of placebo or lithium (another drug used in the treatment of bipolar disorder).
The solution for injection was tested in 581 adults with schizophrenia (compared to placebo or a haloperidol injectable solution) and 228 adults with mania (compared to placebo or an injectable solution of lorazepam, another drug used to treat manic episodes).
In all studies, the efficacy of Zyprexa was assessed using a series of symptom rating scales.

What benefit has Zyprexa shown during the studies?

In all studies, Zyprexa tablets and solution for injection were more effective than placebo at improving symptoms. Zyprexa tablets were as effective as the comparator drugs in treating schizophrenia (haloperidol), treating moderate to severe manic episodes (haloperidol and valproate), and preventing relapse in patients with bipolar disorder (lithium).The solution for injection was also found to be more effective than lorazepam (at a relatively low dose) in people with mania and as effective as haloperidol in the treatment of schizophrenia.

What is the risk associated with Zyprexa?

The most common side effects with Zyprexa (seen in more than 1 in 10 patients) are sleepiness, weight gain and increased levels of prolactin (a hormone). For the full list of side effects reported with Zyprexa, see the package leaflet.
Zyprexa must not be used in people who may be hypersensitive (allergic) to olanzapine or any of the other substances. Zyprexa should not be used in patients at risk of narrow-angle glaucoma (increased pressure in the eye).

Why has Zyprexa been approved?

The Committee for Medicinal Products for Human Use (CHMP) decided that Zyprexa's benefits are greater than its risks for the treatment of schizophrenia in adults, to maintain clinical improvement in follow-up therapy in patients who have demonstrated a positive response to initial treatment. , for the treatment of moderate to severe manic episode, for the prevention of new episodes of illness in patients with bipolar disorder, and in solution for injection for the rapid control of agitation or behavioral disturbances in patients with schizophrenia or episode of mania, when oral therapy is not appropriate. The Committee therefore recommended the granting of a marketing authorization for Zyprexa.

More information about Zyprexa

On 27 September 1996 the European Commission granted Eli Lilly Nederland BV a "Marketing Authorization" for Zyprexa, valid throughout the European Union.
The marketing authorization was renewed on 27 September 2001 and 27 September 2006.
For the full version of the Zyprexa EPAR click here.

Last update of this summary: 09-2008.

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