Fluphenazine versus low-potency antipsychotic drugs for schizophrenia

People with schizophrenia often hear voices or see things (hallucinations) and have strange beliefs (delusions). It is a serious, often long lasting, mental illness that can have a severe detrimental effect on all aspects of the sufferer's life. Antipsychotic drugs are the main treatment for the symptoms of schizophrenia. Fluphenazine is an older antipsychotic that is effective in treating the symptoms of schizophrenia. However, most antipsychotics have side effects and when compared to newer antipsychotic drugs, fluphenazine is thought to be more likely to cause serious movement disorders such as involuntary shaking, tremors, muscle stiffness and the inability to sit still. Fluphenazine is also known to lower people’s mood.

Prescribing low-strength or low-potency drugs can help reduce side effects but are often seen as less effective in treating symptoms.

This review examined the effects of the high-potency antipsychotic fluphenazine compared with those of low-potency antipsychotics. A search for randomised trials comparing these types of drugs was carried out in 2010. The review includes seven studies with 1567 participants. Pooled data from two of these trials did not show a clear difference in effectiveness between fluphenazine and low-potency antipsychotics.

However, evidence showed fluphenazine produced more movement disorders than low-potency antipsychotics, whereas the low-potency drugs were more likely to cause dizziness, drowsiness and sedation, a dry mouth, nausea and sometimes even vomiting.

The number of included studies was low and the quality of evidence provided was moderate. Therefore, further good quality studies would be needed to draw firm conclusions about the relative effectiveness of fluphenazine compared to low-potency antipsychotics.

Important information on service use, going into hospital again (rehospitalisation), costs and quality of life was missing and not reported.

This plain language summary was written by a consumer Ben Gray from RETHINK mental illness.

Authors' conclusions: 

The results do not show a clear difference in efficacy between fluphenazine and low-potency antipsychotics. The number of included studies was low and their quality moderate. Therefore, further studies would be needed to draw firm conclusions about the relative effects of fluphenazine and low-potency antipsychotics.

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Background: 

Antipsychotic drugs are the core treatment for schizophrenia. Treatment guidelines state that there is no difference in efficacy between any other antipsychotic compounds, however, low-potency antipsychotic drugs are often perceived as less efficacious than high-potency compounds by clinicians, and they also seem to differ in their side effects. This review examined the effects of the high-potency antipsychotic fluphenazine compared to those of low-potency antipsychotics.

Objectives: 

To review the effects of fluphenazine and low-potency antipsychotics for people with schizophrenia.

Search strategy: 

We searched the Cochrane Schizophrenia Group Trials Register (November 2010).

Selection criteria: 

We included all randomised controlled trials (RCTs) comparing fluphenazine with first-generation low-potency antipsychotic drugs for people with schizophrenia or schizophrenia-like psychosis.

Data collection and analysis: 

We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model.

Main results: 

The review currently includes seven randomised trials and 1567 participants that compared fluphenazine with low-potency antipsychotic drugs. The size of the included studies was between 40 and 438 participants. Overall, sequence generation, allocation procedures and blinding were poorly reported. Fluphenazine was not significantly different from low-potency antipsychotic drugs in terms of response to treatment (fluphenazine 55%, low-potency drug 55%, 2 RCTs, n = 105, RR 1.06 CI 0.75 to 1.50, moderate quality evidence). There was also no significant difference in acceptability of treatment with equivocal numbers of participants leaving the studies early due to any reason (fluphenazine 36%, low-potency antipsychotics 36%, 6 RCTs, n = 1532, RR 1.00 CI 0.88 to 1.14, moderate quality evidence). There was no significant difference between fluphenazine and low-potency antipsychotics for numbers experiencing at least one adverse effect (fluphenazine 70%, low-potency antipsychotics 88%, 1 RCT, n = 65, RR 0.79 CI 0.58 to 1.07, moderate quality evidence). However, at least one movement disorder occurred significantly more frequently in the fluphenazine group (fluphenazine 15%, low-potency antipsychotics 10%, 3 RCTs, n = 971, RR 2.11 CI 1.41 to 3.15, low quality of evidence). In contrast, low-potency antipsychotics produced significantly more sedation (fluphenazine 20%, low-potency antipsychotics 64%, 1 RCT, n = 65, RR 0.31 CI 0.13 to 0.77, high quality evidence). No data were available for the outcomes of death and quality of life. The results of the primary outcome were robust in a number of subgroup and sensitivity analyses.

Adverse effects such as akathisia (fluphenazine 15%, low-potency antipsychotics 6%, 5 RCTs, n = 1209, RR 2.28 CI 1.58 to 3.28); dystonia (fluphenazine 5%, low-potency antipsychotics 2%, 4 RCTs, n = 1309, RR 2.66 CI 1.25 to 5.64); loss of associated movement (fluphenazine 20%, low-potency antipsychotics 2%, 1 RCT, n = 338, RR 11.15 CI 3.95 to 31.47); rigor (fluphenazine 27%, low-potency antipsychotics 12%, 2 RCTs, n = 403, RR 2.18 CI 1.20 to 3.97); and tremor (fluphenazine 15%, low-potency antipsychotics 6%, 2 RCTs, n = 403, RR 2.53 CI 1.37 to 4.68) occurred significantly more frequently in the fluphenazine group.

For other adverse effects such as dizziness (fluphenazine 8%, low-potency antipsychotics 17%, 4 RCTs, n = 1051, RR 0.49 CI 0.32 to 0.73); drowsiness (fluphenazine 18%, low-potency antipsychotics 25%, 3 RCTs, n = 986, RR 0.67 CI 0.53 to 0.86); dry mouth (fluphenazine 11%, low-potency antipsychotics 18%, 4 RCTs, n = 1051, RR 0.63 CI 0.45 to 0.89); nausea (fluphenazine 4%, low-potency antipsychotics 15%, 3 RCTs, n = 986, RR 0.25 CI 0.14 to 0.45); and vomiting (fluphenazine 3%, low-potency antipsychotics 8%, 3 RCTs, n = 986, RR 0.36 CI 0.18 to 0.72) results favoured fluphenazine with significantly more events occurring in the low-potency antipsychotic group for these outcomes.

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