What is Zyprexa?
Zyprexa is a medicine containing 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 series 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 for the treatment of moderate to severe manic episodes in adults (particularly euphoric mood). It can also be used to prevent the recurrence of manic episodes (reappearance of symptoms) in patients with bipolar disorder (a mental illness characterized by the alternation of manic phases and depressive phases) in patients who have responded to initial treatment.
Zyprexa is normally taken orally; the solution for injection is indicated for the rapid control of agitation or behavioral disorders 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 initial dosage for Zyprexa tablets depends on the disease to be treated: for schizophrenia and the prevention of manic episodes it is 10 mg a day; for the treatment of manic episodes it is 15 mg a day, unless it is used in combination with other drugs, in which case the initial dose may be 10 mg a day. The dosage should be adjusted according to the patient's response and the 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 administered as a single injection into the
muscle. Two hours later, a second injection of 5 or 10 mg can be given. The dosage should be reduced in patients over 65 years of age (5 mg a day for tablets and 2.5-5 mg for a solution for injection) and in subjects with liver or kidney problems (5 mg per day for both tablets and injectable solution).
In any case, the maximum daily dose of Zyprexa, using the tablets or 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 old antipsychotic drugs available since the 1950s. Although its exact mechanism of action is not known, it is nevertheless related to some different receptors present on the surface of nerve cells in the brain. In this way the signals transmitted between the brain cells are interrupted through the "neurotransmitters", ie the chemical substances that allow nerve cells to communicate with each other. It is believed that the beneficial effect of olanzapine is due to its ability to block receptors for neurotransmitters 5- hydroxytryptamine (also called serotonin) and dopamine. Because these neurotransmitters are involved 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 have been studied in approximately 3, 000 adults with schizophrenia, in which the efficacy of the drug has been compared to that of placebo (an ineffective substance on the body) or haloperidol (another antipsychotic drug). Four studies were conducted, all lasting six weeks; the patients involved, however, continued to take the drug for a year or more.
Regarding the treatment of acute manic episodes in adults with bipolar disorder, Zyprexa tablets was compared with placebo, haloperidol or valproate (another drug used in manic episodes) in five studies, including one conducted on patients also to therapy with other drugs. In the prevention of manic episodes, Zyprexa tablets were studied on 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 examined in 581 adults with schizophrenia (compared with placebo or an injection solution of haloperidol) and in 228 adults with mania (compared with placebo or a solution for injection of lorazepam, another drug used in the treatment of manic episodes).
In all studies, the effectiveness of Zyprexa was evaluated using a series of scales for symptom assessment.
What benefit has Zyprexa shown during the studies?
In all of the studies, Zyprexa tablets and solution for injection were more effective than placebo at improving symptoms. Zyprexa tablets were equally effective as comparator drugs in the treatment of schizophrenia (haloperidol), in the treatment of moderate to severe manic episodes (haloperidol and valproate) and in the prevention of recurrences in patients with bipolar disorder (lithium). The solution for injection also proved 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 patient in 10) are drowsiness, increased body weight and increased levels of prolactin (a hormone). For the full list of all side effects reported with Zyprexa, see the Package Leaflet.
Zyprexa should 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 treating schizophrenia in adults, to maintain clinical improvement in follow-up therapy in patients who have shown a positive response to initial treatment, for the treatment of moderate to severe mania episode, for the prevention of new episodes of disease in patients with bipolar disorder, and in injectable solution for the rapid control of agitation or behavioral disorders in patients with schizophrenia or episode of mania, when oral therapy is not appropriate. The Committee therefore recommended that Zyprexa be given marketing authorization.
More information on Zyprexa
On 27 September 1996 the European Commission issued a marketing authorization valid throughout the European Union to Eli Lilly Nederland BV for Zyprexa.
The marketing authorization was renewed on 27 September 2001 and 27 September 2006.
The full EPAR for Zyprexa can be found here.
Last update of this summary: 09-2008.
