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Quetiapine is used alone or together with other medicines to treat bipolar disorder (depressive and manic episodes) and schizophrenia. This medicine should not be used to treat behavioral problems in older adult patients who have dementia or Alzheimer disease. Quetiapine is an antipsychotic medicine that works in the brain. This medicine is available only with your doctor's prescription… Read more
Brand names include
Seroquel XR 14-Day Sample Kit
Drug classes About this
Antipsychotic

What works? Research summarized

Evidence reviews

Quetiapine versus typical antipsychotic drugs for schizophrenia

Antipsychotic drugs are the main treatment for schizophrenia, helping to treat both the positive symptoms (such as hearing voices, seeing things and having strange beliefs) and negative symptoms (including apathy, tiredness and loss of emotion) of this illness. Selecting the most effective antipsychotic drug that can be tolerated by people with schizophrenia is crucial to successful treatment. Older drugs (also known as typical or first generation antipsychotic drugs), such as chlorpromazine and haloperidol, have been used in treating schizophrenia for over 50 years. Although these older drugs are good at treating the positive symptoms of schizophrenia they tend to cause undesirable side effects. These side effects can mean that people do not tolerate or like taking these drugs, which may lead to relapse and admission to hospital. Since 1988, a newer generation of antipsychotic drugs has become available. These new drugs (known as atypical or second generation antipsychotic drugs) are effective in treating the symptoms of schizophrenia but thought to have less side effects than older drugs. However, although newer drugs may cause less side effects such as movement disorders, they have been linked to other side effects like heart problems or weight gain. Quetiapine is a new antipsychotic drug for schizophrenia that has been available for over a decade. However, it is not clear how the effects of quetiapine differ from older antipsychotic drugs. This review evaluated the effectiveness and tolerability of quetiapine versus older antipsychotic drugs. The review included 43 trials with a total of 7217 people. Most studies were from China. In the main, quetiapine did not differ from older drugs for the treatment of positive symptoms of mental illness. There were also no clear differences in terms of the treatment of negative symptoms. However, it is important to note that evidence from these trials suggests quetiapine causes fewer side effects (such as weight gain, dizziness, movement disorders, the inability to sit still, shaking, tremors and abnormal levels of the hormone prolactin, which can contribute to sexual and mental health problems). However, evidence from the trials is limited due to high numbers of people leaving early in almost all of the studies. More evidence through the completion of well designed studies comparing quetiapine with older antipsychotic drugs is needed.

Quetiapine versus other atypical antipsychotic drugs for schizophrenia

Quetiapine is a second‐generation antipsychotic. Second‐generation or atypical antipsychotic drugs have become the mainstay of treatment in many countries for people with schizophrenia. They are called second‐generation drugs because they are newer than the older drugs, known as typical antipsychotics. Second‐generation drugs are thought to be better than the older drugs in reducing the symptoms of schizophrenia, such as hearing voices and seeing things, and are suggested to produce fewer side effects, such as sleepiness, weight gain, tremors and shaking. However, it is not clear how the various second‐ generation antipsychotic drugs differ from one other. The aim of this review therefore was to evaluate the effects of quetiapine compared with other second‐generation antipsychotic drugs for people with schizophrenia. The review included a total of 35 studies with 5971 people, which provided information on six comparisons (quetiapine vs the following: clozapine, olanzapine, risperidone, ziprasidone, paliperidone and aripiprazole). Comparisons with amisulpride, sertindole and zotepine do not exist, so more research is needed. A major limitation of all findings was the large number of people leaving studies and stopping quetiapine treatment (50.2% of people). The most important finding to note is that if a group is started on quetiapine, most will be off this drug within a few weeks (although the reasons for stopping quetiapine treatment are not covered by the review and so remain uncertain). Quetiapine may be slightly less effective than risperidone and olanzapine in reducing symptoms, and it may cause less weight gain and fewer side effects and associated problems (such as heart problems and diabetes) than olanzapine and paliperidone, but more than are seen with risperidone and ziprasidone. The limited information tends to suggest that people taking quetiapine may need to be hospitalised more frequently than those taking risperidone or olanzapine. This may lead to higher costs in some settings, but the information is not robust enough to guide managers.

Second‐generation antipsychotic drugs for major depressive disorder 

This review found 28 studies on five second‐generation antipsychotic drugs (amisulpride, aripiprazole, olanzapine, quetiapine and risperidone) comparing the effects of the drugs alone or adding them or placebo to antidepressants for major depressive disorder and dysthymia. There is evidence that amisulpride might lead to symptom reduction in dysthymia, while no important differences were seen for major depression. There is limited evidence that aripiprazole leads to symptom reduction when added to antidepressants. Olanzapine had no beneficial effects for treatment of depression when compared to antidepressants or compared to placebo but there was limited evidence for the benefits of olanzapine as additional treatment. Data on quetiapine indicated beneficial effects for quetiapine alone or as additional treatment when compared to placebo; data on quetiapine versus duloxetine did not show beneficial effects in terms of symptom reduction for either group, but quetiapine treatment was less well tolerated. The data, however, are very limited. Slight benefits of risperidone as additional treatment, in terms of symptom reduction, are also based on a rather small number of randomised participants. Generally, treatment with second‐generation antipsychotic drugs was associated with worse tolerability, mainly due to sedation, weight gain or laboratory values such as prolactin increase.

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Summaries for consumers

Quetiapine versus typical antipsychotic drugs for schizophrenia

Antipsychotic drugs are the main treatment for schizophrenia, helping to treat both the positive symptoms (such as hearing voices, seeing things and having strange beliefs) and negative symptoms (including apathy, tiredness and loss of emotion) of this illness. Selecting the most effective antipsychotic drug that can be tolerated by people with schizophrenia is crucial to successful treatment. Older drugs (also known as typical or first generation antipsychotic drugs), such as chlorpromazine and haloperidol, have been used in treating schizophrenia for over 50 years. Although these older drugs are good at treating the positive symptoms of schizophrenia they tend to cause undesirable side effects. These side effects can mean that people do not tolerate or like taking these drugs, which may lead to relapse and admission to hospital. Since 1988, a newer generation of antipsychotic drugs has become available. These new drugs (known as atypical or second generation antipsychotic drugs) are effective in treating the symptoms of schizophrenia but thought to have less side effects than older drugs. However, although newer drugs may cause less side effects such as movement disorders, they have been linked to other side effects like heart problems or weight gain. Quetiapine is a new antipsychotic drug for schizophrenia that has been available for over a decade. However, it is not clear how the effects of quetiapine differ from older antipsychotic drugs. This review evaluated the effectiveness and tolerability of quetiapine versus older antipsychotic drugs. The review included 43 trials with a total of 7217 people. Most studies were from China. In the main, quetiapine did not differ from older drugs for the treatment of positive symptoms of mental illness. There were also no clear differences in terms of the treatment of negative symptoms. However, it is important to note that evidence from these trials suggests quetiapine causes fewer side effects (such as weight gain, dizziness, movement disorders, the inability to sit still, shaking, tremors and abnormal levels of the hormone prolactin, which can contribute to sexual and mental health problems). However, evidence from the trials is limited due to high numbers of people leaving early in almost all of the studies. More evidence through the completion of well designed studies comparing quetiapine with older antipsychotic drugs is needed.

Quetiapine versus other atypical antipsychotic drugs for schizophrenia

Quetiapine is a second‐generation antipsychotic. Second‐generation or atypical antipsychotic drugs have become the mainstay of treatment in many countries for people with schizophrenia. They are called second‐generation drugs because they are newer than the older drugs, known as typical antipsychotics. Second‐generation drugs are thought to be better than the older drugs in reducing the symptoms of schizophrenia, such as hearing voices and seeing things, and are suggested to produce fewer side effects, such as sleepiness, weight gain, tremors and shaking. However, it is not clear how the various second‐ generation antipsychotic drugs differ from one other. The aim of this review therefore was to evaluate the effects of quetiapine compared with other second‐generation antipsychotic drugs for people with schizophrenia. The review included a total of 35 studies with 5971 people, which provided information on six comparisons (quetiapine vs the following: clozapine, olanzapine, risperidone, ziprasidone, paliperidone and aripiprazole). Comparisons with amisulpride, sertindole and zotepine do not exist, so more research is needed. A major limitation of all findings was the large number of people leaving studies and stopping quetiapine treatment (50.2% of people). The most important finding to note is that if a group is started on quetiapine, most will be off this drug within a few weeks (although the reasons for stopping quetiapine treatment are not covered by the review and so remain uncertain). Quetiapine may be slightly less effective than risperidone and olanzapine in reducing symptoms, and it may cause less weight gain and fewer side effects and associated problems (such as heart problems and diabetes) than olanzapine and paliperidone, but more than are seen with risperidone and ziprasidone. The limited information tends to suggest that people taking quetiapine may need to be hospitalised more frequently than those taking risperidone or olanzapine. This may lead to higher costs in some settings, but the information is not robust enough to guide managers.

Second‐generation antipsychotic drugs for major depressive disorder 

This review found 28 studies on five second‐generation antipsychotic drugs (amisulpride, aripiprazole, olanzapine, quetiapine and risperidone) comparing the effects of the drugs alone or adding them or placebo to antidepressants for major depressive disorder and dysthymia. There is evidence that amisulpride might lead to symptom reduction in dysthymia, while no important differences were seen for major depression. There is limited evidence that aripiprazole leads to symptom reduction when added to antidepressants. Olanzapine had no beneficial effects for treatment of depression when compared to antidepressants or compared to placebo but there was limited evidence for the benefits of olanzapine as additional treatment. Data on quetiapine indicated beneficial effects for quetiapine alone or as additional treatment when compared to placebo; data on quetiapine versus duloxetine did not show beneficial effects in terms of symptom reduction for either group, but quetiapine treatment was less well tolerated. The data, however, are very limited. Slight benefits of risperidone as additional treatment, in terms of symptom reduction, are also based on a rather small number of randomised participants. Generally, treatment with second‐generation antipsychotic drugs was associated with worse tolerability, mainly due to sedation, weight gain or laboratory values such as prolactin increase.

See all (41)

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