In many countries of the industrialised world second generation ('atypical')
antipsychotics have become the first line drug treatment for people with
schizophrenia. The question as to whether, and if so how much, the effects of the various new generation
antipsychotics differ is a matter of debate. In this review we examined how the efficacy and tolerability of
ziprasidone differs from that of other second generation
antipsychotics.
OBJECTIVES: We extracted data independently. For continuous data, we calculated weighted mean differences (MD) for dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate.
MAIN RESULTS: The review currently includes nine randomised controlled trials (RCTs) with 3361 participants. The overall rate of premature study discontinuation was very high (59.1%). Data for the comparisons of
ziprasidone with
amisulpride,
clozapine,
olanzapine,
quetiapine and
risperidone were available.
Ziprasidone was a less acceptable treatment than
olanzapine (leaving the studies early for any reason: 5 RCTs, n=1937, RR 1.26 CI 1.18 to 1.35, NNH 7 CI 5 to 10) and
risperidone (3 RCTs, n=1029, RR 1.11 CI 1.02 to 1.20, NNH 14 CI 8 to 50), but not than the other second generation
antipsychotic drugs.
Ziprasidone was less efficacious than
amisulpride (leaving the study early due to inefficacy: 1 RCT, n=123, RR 4.72 CI 1.06 to 20.98, NNH 8 CI 5 to 50)
olanzapine (PANSS total score: 4 RCTs, n=1291, MD 8.32 CI 5.64 to 10.99) and
risperidone (PANSS total score: 3 RCTs, n=1016, MD 3.91 CI 0.27 to 7.55). Based on limited data there were no significant differences in tolerability between
ziprasidone and
amisulpride or
clozapine.
Ziprasidone produced less
weight gain than
olanzapine (5 RCTs, n=1659, MD -3.82 CI -4.69 to -2.96),
quetiapine (2 RCTs, n=754, RR 0.45 CI 0.28 to 0.74) or
risperidone (3 RCTs, n=1063, RR 0.49 CI 0.33 to 0.74). It was associated with less
cholesterol increase than
olanzapine,
quetiapine and
risperidone. Conversely
ziprasidone produced slightly more extrapyramidal side-effects than
olanzapine (4 RCTs, n=1732, RR 1.43 CI 1.03 to 1.99, NNH not estimable) and more
prolactin increase than
quetiapine (2 RCTs, n=754, MD 4.77 CI 1.37 to 8.16), but less
movement disorders (2 RCTs, n=822, RR 0.70 CI 0.51 to 0.97, NNT not estimable) and less
prolactin increase (2 RCTs, n=767, MD -21.97 CI -27.34 to -16.60) than
risperidone.
AUTHORS' CONCLUSIONS: