Expert Canadian consensus suggestions on the rational, clinical use of ziprasidone in the treatment of schizophrenia and related psychotic disorders

How Can Drug Metabolism and Transporter Genetics Inform Psychotropic Prescribing?

Many genetic variants in drug metabolizing enzymes and transporters have been shown to be relevant for treating psychiatric disorders. Associations are strong enough to feature on drug labels and for prescribing guidelines based on such data. A range of commercial tests are available; however, there is variability in included genetic variants, methodology, and interpretation. We herein provide relevant background for understanding clinical associations with specific variants, other factors that are relevant to consider when interpreting such data (such as age, gender, drug-drug interactions), and summarize the data relevant to clinical utility of pharmacogenetic testing in psychiatry and the available prescribing guidelines. We also highlight areas for future research focus in this field.

Evidence review and clinical guidance for the use of ziprasidone in Canada

While indicated for schizophrenia and acute mania, ziprasidone's evidence base and use in clinical practice extends beyond these regulatory approvals. We, an invited panel of experts led by a working group of 3, critically examined the evidence and our collective experience regarding the effectiveness, tolerability and safety of ziprasidone across its clinical uses. There was no opportunity for manufacturer input into the content of the review. As anticipated, ziprasidone was found to be effective for its indicated uses, although its utility in mania and mixed states lacked comparative data. Beyond these uses, the available data were either unimpressive or were lacking. An attractive characteristic is its neutral effect on weight thereby providing patients with a non-obesogenic long-term treatment option. Key challenges in practice include the need for dosing on a full stomach and managing its early onset adverse effect of restlessness. Addressing these issues are critical to its long-term success.

Focus on ziprasidone: a review of its use in child and adolescent psychiatry

OBJECTIVE

To review published literature regarding ziprasidone in child and adolescent psychiatry.

METHODS

A literature review was conducted using the medline search term: 'ziprasidone' with limits: Human trials, English language, All Child (Age 0-18). Additional articles were identified from reference information and poster presentation data.

RESULTS

Two randomized controlled trials and five prospective open-label studies have been conducted with ziprasidone. Additionally, several case reports and case series are reviewed. Ziprasidone has a greater propensity for QT(c) prolongation and risk for fatal arrhythmias compared to other atypical antipsychotics. Careful history taking regarding presence of congenital long QT syndrome is essential. Given limited clinical experience, electrocardiogram monitoring at baseline and following attainment of ziprasidone target dosage is warranted. No deaths from overdose have been reported in children and adolescents. Ziprasidone has a low potential for extrapyramidal side effects. Prolactin changes are small and transient. Lethargy, drowsiness, agitation and tachycardia were the most common adverse effects in randomized trials. Body weight changes with ziprasidone were comparable to placebo-treated subjects.

CONCLUSION

At present, ziprasidone should be considered a second or third-line option for a limited set of conditions. A role may exist for ziprasidone in patients who have experienced significant metabolic adverse effects with other atypical antipsychotics.

Modern antipsychotic drugs: a critical overview

Conventional antipsychotic drugs, used for a half century to treat a range of major psychiatric disorders, are being replaced in clinical practice by modern "atypical" antipsychotics, including aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone among others. As a class, the newer drugs have been promoted as being broadly clinically superior, but the evidence for this is problematic. In this brief critical overview, we consider the pharmacology, therapeutic effectiveness, tolerability, adverse effects and costs of individual modern agents versus older antipsychotic drugs. Because of typically minor differences between agents in clinical effectiveness and tolerability, and because of growing concerns about potential adverse long-term health consequences of some modern agents, it is reasonable to consider both older and newer drugs for clinical use, and it is important to inform patients of relative benefits, risks and costs of specific choices.