ABSTRACT
This review will concentrate on the clinical pharmacology, in particular pharmacodynamic data, related to atypical antipsychotics, clozapine, risperidone, paliperidone, olanzapine, que¬tiapine, amisulpride, ziprasidone, aripiprazole, asenapine, iloperidone, lurasidone and cariprazine. A summary of their acute pharmacokinetics properties are also reported. Four new second-generation antipsychotics are available: iloperidone, asenapine, lurasidone and in the next future cariprazine. Similar to ziprasidone and aripiprazole, these new agents are advisable for the lower propensity to give weight gain and metabolic abnormalities in comparison with older second-generation antipsychotics such as olanzapine or clozapine. Actually lurasidone seems to be best in terms of minimizing unwanted alterations in body weight and metabolic variables. Therapeutic drug monitoring is not strictly necessary for all of the new antipsychotic drugs because there are no unequivocal data supporting a relationship between plasma drug levels and clinical outcomes or side effects. The exception can be represented by clozapine for which plasma levels of 350-420 ng/ml are reported to be associated with an increased probability of a good clinical response. Also for olanzapine an established therapeutic range (20-50 ng/ml) is proposed to yield an optimal response and minimize side effects.
ABSTRACT
INTRODUCTION: The aim of this study was to evaluate clinical outcomes and the tolerability of ziprasidone in relation to its plasma levels. METHODS: Thirteen inpatients affected by schizophrenia were included in the study after an acute exacerbation phase. Ziprasidone monotherapy was administered for a period of eight weeks at a mean dose of 123.07+/-30.38 mg/day. Plasma concentrations were measured by high-performance liquid chromatography. RESULTS: Nine patients completed the study. A significant clinical improvement was observed, especially in negative symptoms ( P<0.05), and there was a significant improvement in extrapyramidal symptoms ( P<0.01). Clinical laboratory tests, such as ECG and weight, did not significantly change from baseline. Plasma ziprasidone levels ranged from 20 ng/mL to 160 ng/mL (mean: 75.8 ng/mL) and were significantly related to the improvement in negative symptoms. DISCUSSION: The study showed that ziprasidone was effective and tolerable, that use of ziprasidone was characterized by an absence of extrapyramidal symptoms and weight gain, and that no alterations in clinical laboratory tests occurred. The findings suggest a relationship between plasma levels and the clinical response to negative symptoms of schizophrenia.
