Ziprasidone Overdose: Cases Recorded in the Database of Pfizer-Spain and Literature Review

In vitro degradation of ziprasidone in human whole blood

A systematic study was performed into the degradation of ziprasidone in simulated postmortem blood. Fifteen potential degradation products not previously reported in the literature were observed. Four resulted from degradation in human blood, whereas the remaining products resulted from reaction with solvents: four from alkaline degradation, four from reaction with acetaldehyde, and three from reaction with acetone. To identify possible degradation products, a liquid chromatograph-diode array detector (LC-DAD) and liquid chromatograph quadrupole-time-of-flight mass spectrometer (LC-QTOF-MS) operating in auto-MS/MS mode were used. It was indicated from red-shifted UV-Vis spectra, accurate mass data, mass fragmentation data, and a deuteration experiment that the site of ziprasidone degradation, in the in vitro blood experiments, was the methylene carbon of the oxindole moiety. The major in vitro blood degradation products were proposed to be E/Z isomers of 3-ethylidene-ziprasidone. Further, another in vitro degradation product in microbially inoculated blood specimens was proposed to be 3-ethyl-ziprasidone. 3-Ethylidene-ziprasidone was hypothesized to form from the reaction of ziprasidone with acetaldehyde derived from the ethanol used to spike ziprasidone into the in vitro blood experiments. Data from two postmortem investigations were available for retrospective reanalysis. Attempts were made to detect degradation products of ziprasidone, but none were found.

Ziprasidone suppresses pancreatic adenocarcinoma cell proliferation by targeting GOT1 to trigger glutamine metabolism reprogramming

Pancreatic ductal adenocarcinoma (PDAC) is a fatal malignant tumor whose effective treatment has not been found. The redox state and proliferative activity of PDAC cells are maintained by the conversion of aspartic acid in the cytoplasm into oxaloacetate though aspartate aminotransferase 1 (GOT1). Therefore, GOT1 inhibitors as a potential approach for treating PDAC have attracted more attention of researchers. Ziprasidone effectively inhibited GOT1 in a non-competitive manner. The potential cytotoxicity and anti-proliferation effects of ziprasidone against PDAC cells in vitro and in vivo were evaluated. Ziprasidone can induce glutamine metabolism disorder and redox state imbalance of PDAC cells by targeting GOT1, thereby inhibiting proliferation, preventing migration, and inducing apoptosis. Ziprasidone displayed significant in vivo antitumor efficacy in SW1990 cell-derived xenografts. What's more, knockdown of GOT1 in SW1990 reduced the anti-proliferative effects of ziprasidone. As a novel GOT1 inhibitor, ziprasidone may be a lead compound for the treatment of PDAC. KEY MESSAGES: Small molecule inhibitors targeting GOT1 may provide a therapeutic target in PDAC. Ziprasidone effectively inhibited GOT1 enzyme in a non-competitive manner. Ziprasidone repressed glutamine metabolism and inhibited the growth of tumor in vivo. Knockdown of GOT1 decreased the anti-proliferative effects of ziprasidone.

Ziprasidone induces cytotoxicity and genotoxicity in human peripheral lymphocytes

It has been stated that some antipsychotic drugs might cause genotoxic and carcinogenic effects. Ziprasidone (ZIP) is commonly used an antipsychotic drug. However, its genotoxicity and carcinogenicity data are very limited. The cytotoxicity and genotoxicity of ZIP on human peripheral blood lymphocytes were examined in vitro by sister chromatid exchange (SCE), chromosome aberration (CA) and micronucleus (MN) tests in this study. Lymphocyte cultures were treated with 50, 75 and 100 μg/ml of ZIP in the presence and absence of a metabolic activator (S9 mix). Dimethylsulfoxide was used as a solvent control. While the cells were treated with ZIP for 24 h and 48 h in cultures without S9 mix, the cultures with S9 mix were exposed to ZIP for 3 h. ZIP and its metabolites can exert cytotoxic activities due to significant decreases in mitotic index, proliferation index and nuclear division index in the presence and absence of S9 mix. Statistically significant increases in CAs, aberrant cells and MN values in the presence and absence of S9 mix were found in cultures treated with ZIP. While ZIP significantly increased the SCE values in the absence of S9 mix at all concentrations, increased SCE values in cultures with S9 mix were not found to significantly at all concentrations tested. Our results indicated that both ZIP and its metabolites have cytotoxic, cytostatic and genotoxic potential on lymphocyte cultures under the experimental conditions. Further studies are necessary to make a possible risk assessment in patients receiving therapy with this drug.

Acute dystonia, akathisia, and parkinsonism induced by ziprasidone

Ziprasidone is a second-generation antipsychotic with a lower propensity to cause extrapyramidal adverse effects that are seen at higher doses. We report a patient who developed acute dystonia, parkinsonism, and severe akathisia with ziprasidone 80 mg/d. These adverse effects subsided after dose reduction and specific treatment for akathisia and parkinsonism.

Toxicology and overdose of atypical antipsychotics

BACKGROUND

Second-generation antipsychotic medications, or "atypical antipsychotics," are now first-line therapy in the treatment of schizophrenia and other psychotic disorders, and are additionally being used in a wide array of other psychiatric and non-psychiatric conditions in both adults and children. Overdose is frequently reported to poison control centers.

OBJECTIVES

We review the toxicology and general management of poisonings involving the atypical antipsychotic medications.

DISCUSSION

The most serious toxicity involves the cardiovascular system and the central nervous system. All typical and atypical antipsychotics cause sedation, which is pronounced in overdose. The most common cardiovascular effects that occur after atypical antipsychotic overdose are tachycardia, mild hypotension, and prolongation of the QTc interval. Other clinical syndromes in overdose include neuroleptic malignant syndrome (NMS) and antimuscarinic delirium. Seizures may be observed. No antidotes exist for these poisonings, but they most often do well with supportive care.

CONCLUSION

Antipsychotic overdose produces a gamut of manifestations that affect multiple organ systems. Treatment is primarily supportive. Specific therapies for NMS, hypotension, and seizures are discussed.

Safety of the electroconvulsive therapy-ziprasidone combination

In clinical practice, a nonnegligible proportion of patients with mood or psychotic disorders undergo electroconvulsive therapy (ECT) concomitantly with pharmacotherapy. Ziprasidone, a combined serotonin and dopamine receptor antagonist, is a second-generation antipsychotic agent with a lower incidence of extrapyramidal motor symptoms and prolactin elevation and a safer profile of adverse effects on plasma lipids, glucose levels, and body weight than other antipsychotics. To the best of our knowledge, there are as yet no available reports on the safety of the ECT-ziprasidone combination. We report here on a series of 8 female inpatients who underwent ECT while receiving ziprasidone (20-80 mg/d) as part of their regimen. Seven patients were treated for major depressive episode in the context of unipolar major depressive disorder (n = 5) or of bipolar disorder I (n = 2), whereas 1 patient was treated for exacerbation of schizophrenic symptoms. In all cases, the combination was well tolerated with only minimal adverse effects and unremarkable changes in corrected QT interval.

Unintentional ingestion of ziprasidone in a 22-month-old

Unintentional ingestions are a common presentation to the emergency department in the pediatric population. However, very few ingestions of an atypical antipsychotic, such as ziprasidone, have been described in the emergency medicine literature. While the prevalence of these newer antipsychotics increases in the general population, emergency physicians can expect to see more patients with accidental or intentional overdoses. Many emergency physicians may be unfamiliar with the presentation, initial workup, and expected clinical course of such an overdose. We describe a case of an unintentional ingestion of ziprasidone tablets in a 22-month-old girl who presented to the emergency department with somnolence, drooling, and poor tone.

Practical guidelines for the use of new generation antipsychotic drugs (except clozapine) in adult individuals with intellectual disabilities

New generation antipsychotic (NGA) drugs introduced to the US market after clozapine (aripiprazole, olanzapine, paliperidone, quetiapine, risperidone, and ziprasidone) are frequently used in individuals with intellectual disabilities (ID). However, there is very limited research to fully establish evidence-based or personalized medicine approaches for their use in this population. These guidelines take a pragmatic approach to establishing frameworks for their use by utilizing the prescribing information and reviewing the available literature on other relevant neuropsychiatric disorders. In the absence of expert consensus guidance and well-controlled comparison trials, we present a set of guidelines to inform initiation, dosing and monitoring of use in adults. Further, in these guidelines we provide practical information on drug-drug interactions and adverse drug reactions, and a brief review of discontinuation syndromes, potential for abuse, use during pregnancy and cost considerations. We also provide drug utilization review forms for each NGA to facilitate implementation of these guidelines, these guidelines provide a practical and necessary resource for practitioners treating psychiatric disorders and challenging behaviors in adult individuals with ID.

A systematic review of cardiovascular effects after atypical antipsychotic medication overdose

As the use of atypical antipsychotic medications (AAPMs) increases, the number of overdoses continues to grow. Cardiovascular toxicity was common with older psychiatric medications but seems uncommon with AAPM. We conducted a systematic literature review to describe the cardiovascular effects reported after overdose of 5 common AAPM: aripiprazole, olanzapine, quetiapine, risperidone, and ziprasidone. We included case reports and case series describing overdose of these 5 medications identified in a search of MEDLINE, EMBASE, and abstracts from major toxicology meetings. We found 13 pediatric cases (age, <7 years), 22 adolescent cases (age, 7-16 years), and 185 adult cases. No pediatric case described a ventricular dysrhythmia or a cardiovascular death. In the adolescent and adult cases, we found numerous reports of prolonged corrected QT interval and hypotension, but there were only 3 cases of ventricular dysrhythmia and 3 deaths that may have been due to direct cardiovascular toxicity. The results from case series reports were similar to the single case report data. Our review suggests that overdose of AAPM is unlikely to cause significant cardiovascular toxicity.

Prospective observational multi-poison center study of ziprasidone exposures

BACKGROUND

Ziprasidone is an atypical antipsychotic associated with QTc prolongation during therapeutic use. We characterized the clinical manifestations associated with ziprasidone overdoses, in particular the incidence and severity of QTc prolongation.

METHODS

Four regional poison centers prospectively collected ziprasidone overdose data from August 1, 2003 to October 1, 2005. Cases were included if they were followed to known medical outcome and comprised single-substance ziprasidone exposures or with co-ingestants not associated with prolongation of the QTc interval.

RESULTS

Fifty-six ziprasidone exposures met inclusion criteria. The most common clinical effects were drowsiness (N=38, 67.9%) and tachycardia (N=19, 33.9%). QTc prolongation (>0.500 second) occurred in only one patient. Seven patients had QTc intervals of 0.450 to 0.500 second. Medical outcomes were coded as no effect (13, 23.2%), minor effect (21, 35.5%), moderate effect (20, 35.7%), or major effect (2, 3.4%).

CONCLUSION

Common clinical effects following ziprasidone overdose are drowsiness and tachycardia. Clinically significant QTc prolongation occurs infrequently.

Ziprasidone in the treatment of mania in bipolar disorder

Ziprasidone is an atypical antipsychotic with a unique receptor-binding profile. Currently, ziprasidone is approved by the US Food and Drug Administration for the acute treatment of psychosis in schizophrenia and mania in bipolar disorder. When compared to certain other atypical antipsychotics, ziprasidone appears to have a relatively benign side effect profile, especially as regards metabolic effects eg, weight gain, serum lipid elevations and glucose dysregulation. Taken together, these data suggest that ziprasidone may be a first line treatment for patients with bipolar mania. However, ziprasidone is a relatively new medication for which adverse events after long-term use and/or in vulnerable patient populations must be studied. Unstudied areas of particular importance include the efficacy and safety of ziprasidone in the treatment of bipolar depression and relapse prevention of mania as, well as in the subpopulations of pregnant women, the elderly and pediatric patients. The emergence of mania in patients taking ziprasidone is another topic for further study.

High-dose ziprasidone-induced acute dystonia

There are few clinical data describing the relative risks of extrapyramidal symptoms (EPS) at higher doses of ziprasidone (i.e., greater than 160 mg/day) when compared to lower doses. We report on a patient who displayed no EPS with ziprasidone 160 mg/day for several months, but did display marked, acute dystonic reactions on ziprasidone 240 mg/day. The observations from the present case indicate that high-dose, ziprasidone-induced acute dystonia may occur even if no such side effects have been experienced at doses up to and including 160 mg/day.