Pharmacokinetics and Therapeutics of Acute Intramuscular Ziprasidone

Optimisation of pharmacotherapy in psychiatry through therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests: focus on antipsychotics

BACKGROUND

For psychotic disorders (i.e. schizophrenia), pharmacotherapy plays a key role in controlling acute and long-term symptoms. To find the optimal individual dose and dosage strategy, specialized tools are used. Three tools have been proven useful to personalize drug treatments: therapeutic drug monitoring (TDM) of drug levels, pharmacogenetic testing (PG), and molecular neuroimaging.

METHODS

In these Guidelines, we provide an in-depth review of pharmacokinetics, pharmacodynamics, and pharmacogenetics for 50 antipsychotics. Over 30 international experts in psychiatry selected studies that have measured drug concentrations in the blood (TDM), gene polymorphisms of enzymes involved in drug metabolism, or receptor/transporter occupancies in the brain (positron emission tomography (PET)).

RESULTS

Study results strongly support the use of TDM and the cytochrome P450 (CYP) genotyping and/or phenotyping to guide drug therapies. Evidence-based target ranges are available for titrating drug doses that are often supported by PET findings.

CONCLUSION

All three tools discussed in these Guidelines are essential for drug treatment. TDM goes well beyond typical indications such as unclear compliance and polypharmacy. Despite its enormous potential to optimize treatment effects, minimize side effects and ultimately reduce the global burden of diseases, personalized drug treatment has not yet become the standard of care in psychiatry.

Haloperidol Versus Ziprasidone With Concomitant Medications and Other Predictors of Physical Restraint Duration in the Emergency Department

BACKGROUND

Patients with severe agitation are frequently encountered in the emergency department (ED). At times, these patients are physically restrained and given calming medications; however, little is known about the effects of medications and other predictors on restraint duration.

OBJECTIVE

Our aim was to compare restraint duration when haloperidol or ziprasidone was used as the primary antipsychotic with or without concomitant medications, and to identify predictors of restraint duration.

METHODS

We performed a review of a retrospective cohort of physically restrained ED patients between January 1, 2013 and November 30, 2017. An unadjusted analysis and adjusted linear regression model were used to evaluate the effect of antipsychotic choice on restraint duration, controlling for sex, age, race, homelessness, arrival in restraints, re-restraint during visit, concomitant medications (i.e., benzodiazepines or anticholinergics), additional medications given during restraint, time of day, and patient disposition.

RESULTS

In 386 patients (319 haloperidol, 67 ziprasidone), the average restraint duration was 2.4 h (95% confidence interval [CI] 2.2 to 2.6 h). There were no differences in physical restraint times between ziprasidone and haloperidol groups in the unadjusted (mean difference 0.12 h; 95% CI -0.42 to 0.66 h) or adjusted analyses (-12.7%; 95% CI -33.9% to 8.6%). Haloperidol given with diphenhydramine alone was associated with decreased restraint duration (-30.8%; 95% CI -50.6% to -11.1%) The largest association with restraint duration was administration of additional sedating medications during restraint, prolonging restraint by 62% (95% CI 27.1% to 96.9%). In addition, compared with White patients, Black patients spent significantly more time restrained (mean difference 33.9%; 95% CI 9.0% to 58.9%).

CONCLUSIONS

Restraint duration of agitated ED patients was similar when haloperidol or ziprasidone was used as the primary antipsychotic. However, race and additional medications given during restraint were significantly associated with restraint duration.

Evaluating the neurotherapeutic potential of a water-soluble progesterone analog after traumatic brain injury in rats

The poor aqueous solubility of progesterone (PROG) limits its potential use as a therapeutic agent. We designed and tested EIDD-1723, a novel water-soluble analog of PROG with >100-fold higher solubility than that of native PROG, as candidate for development as a field-ready treatment for traumatic brain injury (TBI). The pharmacokinetic effects of EIDD-1723 on morphological and functional outcomes in rats with bilateral cortical impact injury were evaluated. Following TBI, 10-mg/kg doses of EIDD-1723 or PROG were given intramuscularly (i.m.) at 1, 6 and 24 h post-injury, then daily for the next 6 days, with tapering of the last 2 treatments. Rats were tested pre-injury to establish baseline performance on grip strength and sensory neglect, and then retested at 4, 9 and 21 days post-TBI. Spatial learning was evaluated from days 11-17 post-TBI. At 22 days post-injury, rats were perfused and brains extracted and processed for lesion size. For the edema assay the animals were killed and brains removed at 24 h post-injury. EIDD-1723 significantly reduced cerebral edema and improved recovery from motor, sensory and spatial learning deficits as well as, or better than, native PROG. Pharmacokinetic investigation after a single i.m. injection in rats revealed that EIDD-1723 was rapidly converted to the active metabolite EIDD-036, demonstrating first-order elimination kinetics and ability to cross the blood-brain barrier. Our results suggest that EIDD-1723 represents a substantial advantage over current PROG formulations because it overcomes storage, formulation and delivery limitations of PROG and can thereby reduce the time between injury and treatment.

Preparation and evaluation of ziprasidone–phospholipid complex from sustained-release pellet formulation with enhanced bioavailability and no food effect

Objectives

The purpose of this work was to develop ziprasidone–phospholipid complex (ZIP-PLC) in sustained-release pellets to enhance the oral bioavailability and overcome the food effect of ziprasidone.

Methods

Ziprasidone–phospholipid complex was formulated by solvent-evaporation method. The complexes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and solubility testing. The optimized ZIP-PLC was used to prepare ZIP-PLC sustained-release pellets via extrusion–spheronization method. The pellets were characterized by in vitro drug-release studies and administered to fasted and fed beagle dogs, and their pharmacokinetics were compared with commercial formulation Zeldox capsule as a control.

Key findings

The results of FTIR, SEM, DSC and PXRD studies confirmed the formation of phospholipid complex. Solubility studies showed there was a higher solubility in water for ZIP-PLC than monohydrate ziprasidoe. The in vitro release rate of ziprasidone from the ZIP-PLC sustained-release pellet exhibited controlled-release characteristics with over 95% total release in 12 h. Pharmacokinetic studies in beagle dogs showed ziprasidone with prolong actions, and no food effect was achieved simultaneously in ZIP-PLC sustained-release pellet compared with Zeldox capsule.

Conclusions

The results indicated a sustained release with prolonged actions of schizophrenia and bipolar disorder treatment.

Evaluation of the pharmacokinetics, safety and clinical efficacy of ziprasidone for the treatment of schizophrenia and bipolar disorder

INTRODUCTION

Multiple strategies exist for the pharmacological treatment of schizophrenia and related disorders. In the last 20 years, several 'new' compounds have been introduced, called 'atypical antipsychotics', which have higher efficacy and better tolerability than first-generation neuroleptics. Among them, ziprasidone (ZPR) is currently finding widespread use, and it has also been shown to be active as an augmenter in bipolar disorder therapy.

AREAS COVERED

This review aims to provide the latest information on ZPR, an 'atypical' agent for the pharmacological therapy of schizophrenia and bipolar disorder. A literature search has been carried out with the keywords 'ziprasidone', 'schizophrenia', 'psychosis', 'bipolar', 'pharmacokinetics' and 'clinical trials'. In this process, particular attention has been paid to the drug pharmacokinetic characteristics and its safety in clinical use.

EXPERT OPINION

ZPR shares most advantages and disadvantages with other atypical antipsychotics. However, it can be useful for its low tendency to cause metabolic syndrome and hyperprolactinaemia, especially in patients suffering from excess weight, hyperlipidaemia, diabetes or who have suffered from hyperprolactinaemia when using other antipsychotics. However, there are serious doubts as to whether ZPR should be administered to patients suffering from arrhythmias or QTc prolongation, and even more for administration to bipolar patients undergoing polypharmacy with antidepressants.

Ziprasidone: efficacy and safety in patients with bipolar disorder

Atypical antipsychotics have been increasingly shown to have efficacy in the treatment of various phases of bipolar disorder. Ziprasidone acts primarily through serotonergic and dopaminergic receptor antagonism, and exerts effects as an inhibitor of serotonin and norepinephrine reuptake. Ziprasidone exhibits dose proportional, linear changes in exposure and is hepatically metabolized primarily by aldehyde oxidase. In studies of patients with acute manic or mixed episodes, treatment with ziprasidone monotherapy or in combination with lithium, resulted in rapid symptom improvement and was generally well tolerated. Results from open-label extension studies of ziprasidone indicate continued improvement in manic symptoms. Preliminary data in pediatric patients with bipolar disorder also suggest it may be efficacious in this population. Ziprasidone is considered as a first-line treatment option in patients with bipolar manic or mixed episodes, with or without psychosis and displays a favorable side-effect profile.

Management of acute agitation in the emergency department

Acutely agitated and combative patients are commonly seen and evaluated by health care providers in the emergency department. Treatment options have evolved significantly in recent years with the advent of intramuscular atypical antipsychotics and an expanded repertoire of patient-friendly oral formulations. Selection of the ideal pharmacologic treatment of an acutely agitated patient strengthens the patient-prescriber relationship and promotes adherence to future therapy. In this article, advantages and disadvantages of various treatment modalities for undifferentiated, psychotic, and nonpsychotic agitation are reviewed, including alternatives to the commonly prescribed haloperidol and lorazepam combination. Atypical antipsychotics may be superior in certain patients, with the added benefit of easier conversion to maintenance therapy. Special consideration is given to the treatment of acutely agitated geriatric patients suffering from delirium and/or dementia. Management of these patients should be guided by etiology and patient characteristics to obtain maximum therapeutic benefit. Although emergency department providers may only see a given patient once, the health care team must have an evidence-based approach to the care that is provided in the emergency department, as it can significantly influence the patient's overall course of treatment in the outpatient setting.

Natural gums as sustained release carriers: development of gastroretentive drug delivery system of ziprasidone HCl

Background

Objective of this study is to show the potential use of natural gums in the development of drug delivery systems. Therefore in this work gastro retentive tablet formulations of ziprasidone HCl were developed using simplex lattice design considering concentration of okra gum, locust bean gum and HPMC K4M as independent variables. A response surface plot and multiple regression equations were used to evaluate the effect of independent variables on hardness, f_lag time, floating time and drug release for 1 h, 2 h, and 8 h and for 24 h. A checkpoint batch was also prepared by considering the constraints and desirability of optimized formulation to improve its in vitro performance. Significance of result was analyzed using ANOVA and p < 0.05 was considered statistically significant.

Results

Formulation chiefly contains locust bean gum found to be favorable for hardness and floatability but combined effect of three variables was responsible for the sustained release of drug. The in vitro drug release data of check point batch (F8) was found to be sustained well compared to the most satisfactory formulation (F7) of 7 runs. The ‘n’ value was found to be between 0.5 and 1 suggesting that release of drug follows anomalous (non-fickian) diffusion mechanism indicating both diffusion and erosion mechanism from these natural gums. Predicted results were almost similar to the observed experimental values indicating the accuracy of the design. In vivo floatability test indicated non adherence to the gastric mucosa and tablets remain buoyant for more than 24 h.

Conclusions

Study showed these eco-friendly natural gums can be considered as promising SR polymers.

Pharmacokinetics of loxapine following inhalation of a thermally generated aerosol in healthy volunteers

The objective of this randomized, double-blind, placebo-controlled, dose escalation study was to determine the pharmacokinetic characteristics, safety, and tolerability of single doses of inhaled loxapine aerosol in healthy volunteers. Loxapine was delivered by means of a unique thermally generated aerosol comprising drug particles of a size designed for deep lung delivery and absorption. Fifty participants were randomized to receive 0.625, 1.25, 2.5, 5.0, or 10 mg of loxapine aerosol or placebo. Following inhalation, the t(max) median (25%, 75%) was 2 (1, 3) minutes. The loxapine AUC(infinity) was dose proportional across all doses with slope (90% confidence interval) of log AUC(infinity) versus log dose = 0.909 (0.832, 0.987). No clinically meaningful changes were noted in hematology results, blood chemistry, vital signs, or respiratory function. The most common adverse events were dizziness, somnolence, and bad taste. The inhalation of Staccato loxapine represents a safe, well-tolerated means for rapidly achieving therapeutic plasma concentrations of loxapine.

P wave and QT changes among inpatients with schizophrenia after parenteral ziprasidone administration

OBJECTIVE

Although ziprasidone has been reported to cause ventricular arrhythmias, there have been no studies regarding the influence of ziprasidone on atrial conduction. Intraatrial and interatrial conduction time prolongation and inhomogeneous propagation of sinus impulses are indicated by P wave changes on surface electrocardiography. We aimed to evaluate proneness to atrial fibrillation after intramuscular ziprasidone in drug-free inpatients with schizophrenia.

METHODS

We evaluated 11 eligible inpatients who were drug free for at least 4 weeks with a primary diagnosis of schizophrenia disorder and 11 healthy controls who were hospital staff members. Electrocardiography was performed at baseline and 1.5-2h after ziprasidone injection. A 12-lead surface electrocardiogram was obtained from each subject in the supine position at a paper speed of 50mm/s and 2mV/cm.

RESULTS

The changes between baseline and the period after parenteral ziprasidone administration in P-wave duration, P-wave dispersion, QTc, QTc(max), QTc(min), and QT dispersion variables were significant (p>0.05). The initial P-wave dispersion was significantly longer in patients than in healthy controls (p<0.05). There were no correlations between electrocardiography parameters and clinical severity scores or demographic variables in either group.

CONCLUSION

Intramuscular ziprasidone administration does not seem to influence atrial and ventricular electrical conduction in drug-free inpatients with schizophrenia. However, schizophrenia might affect atrial conduction resulting in atrial fibrillation, which may be a cause of some complications in inpatients with this schizophrenia.

Ziprasidone in the treatment of affective disorders: a review

Ziprasidone was the fifth atypical antipsychotic approved by Food and Drug Administration (FDA) for use in bipolar mania and mixed episodes. This atypical antipsychotic has a unique profile, as it acts primarily through serotonergic and dopaminergic receptor antagonism, but also exerts effects as an inhibitor of norepinephrine reuptake. Moreover, one of the advantages of ziprasidone is its safety profile as it is not associated with clinically significant metabolic side effects and little or no effect on prolactin level or anticholinergic side effects. Most of the studies evaluating ziprasidone's efficacy and safety are short-term double-blind, placebo-controlled studies in acute mania and mixed episodes. In two of them, ziprasidone was associated to significant improvement in the primary measures assessed. However, an add-on study, lithium plus ziprasidone showed similar results than lithium monotherapy, although there was a significant advantage for the combination within the first week. In a more recent trial, ziprasidone was compared with placebo and haloperidol as monotherapies, again beating placebo. In that trial, ziprasidone appeared to be safer and better tolerated, although less likely efficacious than haloperidol. Particularly, subjects treated with ziprasidone were less likely to switch to depression. Despite the well-studied efficacy of ziprasidone in the first weeks of treatment, there are no controlled trials that evaluate the role and efficacy of ziprasidone in long-term treatment of bipolar disorder (BD). Overall, in the open-label extension studies, there was a global improvement at all visits compared with baseline scores. Furthermore, ziprasidone appears to offer some antidepressant effect in patients with major depressive episode and resistant to treatment, as demonstrated in add-on open-label studies with ziprasidone plus selective serotonin reuptake inhibitor (SSRI).

Ziprasidone for schizophrenia and bipolar disorder: a review of the clinical trials

Ziprasidone is a newer "atypical" or "second-generation" antipsychotic. Oral ziprasidone (ziprasidone hydrochloride) is approved by the U.S. Food and Drug Administration (FDA) for the treatment of schizophrenia, and acute manic or mixed episodes associated with bipolar disorder (with or without psychotic features). Ziprasidone intramuscular (ziprasidone mesylate) is FDA-approved for acute agitation in patients with schizophrenia. Oral ziprasidone appears efficacious, and has been shown to have some limited clinical advantages over chlorpromazine and haloperidol in ameliorating negative symptoms of schizophrenia. In Phase 2 of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) for schizophrenia, ziprasidone did not match the clinical performance of olanzapine and risperidone, appearing closer in overall effectiveness to quetiapine. The rate of dose titration and the dose achieved may have an important bearing on ziprasidone's efficacy profile. In studies of usage for acute agitation in individuals with schizophrenia, intramuscular ziprasidone has been shown to be efficacious and relatively well tolerated. Regarding tolerability, ziprasidone, has important advantages in that it is not associated with clinically significant weight gain or adverse changes in cholesterol, triglycerides, or glycemic control, and patients may experience moderate improvement in these measures when switching to ziprasidone from a different antipsychotic agent. It also lacks significant persistent effects on prolactin levels, is not anticholinergic, and only infrequently causes extrapyramidal side effects or postural hypotension, although it can be associated with somnolence. This tolerability profile may be quite valuable in the treatment of some patients. Ziprasidone may prolong the electrocardiogram (ECG) QTc interval (QT interval corrected for heart rate by a standard algorithm), but after 5 years' clinical availability ziprasidone (by itself) does not appear to pose a substantial clinical problem in this regard. Therefore, ziprasidone may be considered a first-line drug option in the treatment of schizophrenia or manic episodes, but, in view of the differences among antipsychotic medications, drug selection should be guided by the patient's individual characteristics and situation.

A retrospective chart review of intramuscular ziprasidone for agitation in children and adolescents on psychiatric units: prospective studies are needed

OBJECTIVE

Our primary objective was to evaluate the effectiveness and tolerability of intramuscular ziprasidone for impulsivity and agitation in psychiatrically hospitalized children and adolescents. Our secondary objective was to examine demographic and clinical factors associated with treatment response.

METHOD

We conducted a retrospective chart review of children and adolescents admitted to Cincinnati Children's Hospital Medical Center (CCHMC) psychiatric units between January 1, 2002, and July 11, 2005, who received intramuscular ziprasidone. Medical records were reviewed to determine demographic and clinical information as well as tolerability and effectiveness of ziprasidone. The Behavioral Activity Rating Scale (BARS) was used retrospectively to assess clinical response. Regression analyses were performed to evaluate the effect of demographic factors (age, gender, and ethnicity) and primary psychiatric diagnoses on treatment response. Electrocardiogram (ECG) data was inadequate.

RESULTS

Fifty nine children and adolescents received a total of 77 injections of intramuscular ziprasidone for acute agitation. The mean +/- SD BARS score decreased from 6.5 +/- 0.7 to 3.1 +/- 1.3. The most common side effect was drowsiness or falling asleep (n = 46, 60%). Three (4%) could not be roused after the injection.

CONCLUSIONS

Intramuscular ziprasidone may be helpful for agitation but often caused oversedation. Safety data, including ECGs, is needed in controlled prospective studies.

Clinical Pharmacokinetics of Atypical Antipsychotics

In the past, the information about the dose-clinical effectiveness of typical antipsychotics was not complete and this led to the risk of extrapyramidal adverse effects. This, together with the intention of improving patients' quality of life and therapeutic compliance, resulted in the development of atypical or second-generation antipsychotics (SGAs). This review will concentrate on the pharmacokinetics and metabolism of clozapine, risperidone, olanzapine, quetiapine, amisulpride, ziprasidone, aripiprazole and sertindole, and will discuss the main aspects of their pharmacodynamics. In psychopharmacology, therapeutic drug monitoring studies have generally concentrated on controlling compliance and avoiding adverse effects by keeping long-term exposure to the minimal effective blood concentration. The rationale for using therapeutic drug monitoring in relation to SGAs is still a matter of debate, but there is growing evidence that it can improve efficacy, especially when patients do not respond to therapeutic doses or when they develop adverse effects. Here, we review the literature concerning the relationships between plasma concentrations of SGAs and clinical responses by dividing the studies on the basis of the length of their observation periods. Studies with clozapine evidenced a positive relationship between plasma concentrations and clinical response, with a threshold of 350-420 ng/mL associated with good clinical response. The usefulness of therapeutic drug monitoring is well established because high plasma concentrations of clozapine can increase the risk of epileptic seizures. Plasma clozapine concentrations seem to be influenced by many factors such as altered cytochrome P450 1A4 activity, age, sex and smoking. The pharmacological effects of risperidone depend on the sum of the plasma concentrations of risperidone and its 9-hydroxyrisperidone metabolite, so monitoring the plasma concentrations of the parent compound alone can lead to erroneous interpretations. Despite a large variability in plasma drug concentrations, the lack of studies using fixed dosages, and discrepancies in the results, it seems that monitoring the plasma concentrations of the active moiety may be useful. However, no therapeutic plasma concentration range for risperidone has yet been clearly established. A plasma threshold concentration for parkinsonian side effects has been found to be 74 ng/mL. Moreover, therapeutic drug monitoring may be particularly useful in the switch between the oral and the long-acting injectable form. The reviewed studies on olanzapine strongly indicate a relationship between clinical outcomes and plasma concentrations. Olanzapine therapeutic drug monitoring can be considered very useful in assessing therapeutic efficacy and controlling adverse events. A therapeutic range of 20-50 ng/mL has been found. There is little evidence in favour of the existence of a relationship between plasma quetiapine concentrations and clinical responses, and an optimal therapeutic range has not been identified. Positron emission tomography studies of receptor blockade indicated a discrepancy between the time course of receptor occupancy and plasma quetiapine concentrations. The value of quetiapine plasma concentration monitoring in clinical practice is still controversial. Preliminary data suggested that a therapeutic plasma amisulpride concentration of 367 ng/mL was associated with clinical improvement. A therapeutic range of 100-400 ng/mL is proposed from non-systematic clinical experience. There is no direct evidence concerning optimal plasma concentration ranges of ziprasidone, aripiprazole or sertindole.

Psychopharmacology in pediatric critical care

Psychopharmacologic treatment in pediatric critical care requires a careful child or adolescent psychiatric evaluation, including a thorough review of the history of present illness or injury, any current or pre-existing psychiatric disorder, past history, and laboratory studies. Although there is limited evidence to guide psychopharmacologic practice in this setting, psychopharmacologic treatment is increasing in critical care, with known indications for treatment, benefits, and risks; initial dosing guidelines; and best practices. Treatment is guided by the knowledge bases in pediatric physiology, psycho-pharmacology, and treatment of critically ill adults. Pharmacologic considerations include pharmacokinetic and pharmcodynamic aspects of specific drugs and drug classes, in particular elimination half-life, developmental considerations, drug interactions, and adverse effects. Evaluation and management of pain is a key initial step, as pain may mimic psychiatric symptoms and its effective treatment can ameliorate them. Patient comfort and safety are primary objectives for children who are acutely ill and who will survive and for those who will not. Judicious use of psychopharmacolgic agents in pediatric critical care using the limited but growing evidence base and a clinical best practices collaborative approach can reduce anxiety,sadness, disorientation, and agitation; improve analgesia; and save lives of children who are suicidal or delirious. In addition to pain, other disorders or indications for psychopharmacologic treatment are affective disorders;PTSD; post-suicide attempt patients; disruptive behavior disorders (especially ADHD); and adjustment, developmental, and substance use disorders. Treating children who are critically ill with psychotropic drugs is an integral component of comprehensive pediatric critical care in relieving pain and delirium; reducing inattention or agitation or aggressive behavior;relieving acute stress, anxiety, or depression; and improving sleep and nutrition. In palliative care, psychopharmacology is integrated with psychologicapproaches to enhance children's comfort at the end of life. Defining how best to prevent the adverse consequences of suffering and stress in pediatric critical care is a goal for protocols and for new psychopharmacologic research [23,153].