Torsades De Pointes after Administration of Low-Dose Aripiprazole

Inhibition of voltage-gated potassium channel by aripiprazole in rabbit coronary arterial smooth muscle cells

Aripiprazole, a third-generation antipsychotic, has been widely used to treat schizophrenia. In this study, we evaluated the effect of aripiprazole on voltage-gated potassium (Kv) channels in rabbit coronary arterial smooth muscle cells using the patch clamp technique. Aripiprazole reduced the Kv current in a concentration-dependent manner with a half-maximal inhibitory concentration of 0.89 ± 0.20 μM and a Hill coefficient of 1.30 ± 0.25. The inhibitory effect of aripiprazole on Kv channels was voltage-dependent, and an additional aripiprazole-induced decrease in the Kv current was observed in the voltage range of full channel activation. The decay rate of Kv channel inactivation was accelerated by aripiprazole. Aripiprazole shifted the steady-state activation curve to the right and the inactivation curve to the left. Application of a repetitive train of pulses (1 and 2 Hz) promoted inhibition of the Kv current by aripiprazole. Furthermore, the recovery time constant from inactivation increased in the presence of aripiprazole. Pretreatment of Kv1.5 subtype inhibitor reduced the inhibitory effect of aripiprazole. However, pretreatment with Kv 7 and Kv2.1 subtype inhibitors did not change the degree of aripiprazole-induced inhibition of the Kv current. We conclude that aripiprazole inhibits Kv channels in a concentration-, voltage-, time-, and use (state)-dependent manner by affecting the gating properties of the channels.

The impact of adjunctive aripiprazole on QT interval: A 12-week open label study in patients on olanzapine, clozapine or risperidone

OBJECTIVE

To evaluate the effect of adjunct aripiprazole on QT of patients clinically stabilized on atypical antipsychotics.

METHODS

The dataset was from an open-label 12-week prospective trial that evaluated adjunctive use of 5 mg/day of aripiprazole on metabolic profile in patients with schizophrenia, or schizoaffective disorder stabilized on olanzapine, clozapine, or risperidone. Bazett-corrected QT (QTc) was manually calculated from ECGs measured at baseline (before aripiprazole) and week 12, by two doctors blind to the diagnosis and atypical antipsychotic. The change in QTc (∆QTc: baseline QTc-week 12 QTc) and the number of participants in normal, borderline, prolonged, and pathological groups after 12 weeks were analyzed.

RESULTS

Fifty-five participants, mean age of 39.3 (SD 8.2) years, were analyzed. The ∆QTc after 12 weeks was 5.9 ms (p = 0.143) for the whole sample; 16.4 ms (p = 0.762), 3.7 ms (p = 0.480) and 0.5 ms (p = 0.449), for the clozapine, risperidone and olanzapine group, respectively. There was no significant statistical difference comparing the change in QTc overall, and between atypical antipsychotic groups, when evaluating from baseline to endpoint. However, stratifying the sample based on sex-dependent QTc cut-offs showed a 45% decrease in abnormal QTc readings (p = 0.049) after aripiprazole initiation; 20 subjects had abnormal QTc at baseline, while only 11 subjects had abnormal QTc at 12 weeks. 25.5% of participants showed a reduction in at least one QTc severity group, while 65.5% had no change and 9.0% worsened in QTc group, after 12 weeks of adjunct aripiprazole.

CONCLUSION

Low-dose adjunctive aripiprazole did not prolong QTc in patients stabilized on either olanzapine, risperidone, or clozapine. More controlled studies evaluating the QTc effect of adjunctive aripiprazole should be done to confirm and support these findings.

Practical Approaches to Antipsychotic-Associated Corrected QT Interval Prolongation in Patients With Serious Mental Illness: A Review of Cases

BACKGROUND

There is no consensus for assessment and management of patients with serious mental illness (SMI) who are at risk for cardiac morbidity and mortality due to antipsychotic-associated QTc prolongation.

OBJECTIVE

The objective of this review was to assess methods for risk scoring, QT correction calculation, and clinical management in SMI patients with antipsychotic-associated QTc prolongation.

METHODS

A search was performed in PubMed for case reports that described QTc prolongation in adult patients with schizophrenia or bipolar disorder prescribed an antipsychotic. Reports published in North America between 2000 and 2020 were eligible. The Mayo, Tisdale, and RISQ-PATH scoring tools were applied to cases to categorize risk level.

RESULTS

Seventeen cases were included. Most patients were prescribed a second-generation antipsychotic for schizophrenia, with baseline and maximum QTc values of 429 milliseconds and 545 milliseconds, respectively. The Mayo scoring tool identified 17 (100%) cases as "high risk," Tisdale identified 9 (53%) cases as "moderate risk" and 7 (41%) cases as "low risk," while RISQ-PATH identified 9 (53%) cases as "not low risk" and 8 (47%) cases as "low risk." Three cases reported the QT correction formula utilized (18%). The most common intervention to address antipsychotic-associated QTc prolongation was switching to a different antipsychotic (35%). Approximately one third of patients experienced Torsades de Pointes.

CONCLUSION

There is a lack of standardization for antipsychotic-associated QTc prolongation risk assessment and management in patients with SMI. This review provides real-world data representing actual clinical practice.

QTc Interval Prolongation with Therapies Used to Treat Patients with Parkinson's Disease Psychosis: A Narrative Review

In addition to the classic motor symptoms of Parkinson's disease (PD), people with PD frequently experience nonmotor symptoms that can include autonomic dysfunction and neuropsychiatric symptoms such as PD psychosis (PDP). Common patient characteristics, including older age, use of multiple medications, and arrhythmias, are associated with increased risk of corrected QT interval (QTc) prolongation, and treatments for PDP (antipsychotics, dementia medications) may further increase this risk. This review evaluates how medications used to treat PDP affect QTc interval from literature indexed in the PubMed and Embase databases. Although not indicated for the treatment of psychosis, dementia therapies such as donepezil, rivastigmine, memantine, and galantamine are often used with or without antipsychotics and have minimal effects on QTc interval. Among the antipsychotics, data suggesting clinically meaningful QTc interval prolongation are limited. However, many antipsychotics have other safety concerns. Aripiprazole, olanzapine, and risperidone negatively affect motor function and are not recommended for PDP. Quetiapine is often sedating, can exacerbate underlying neurogenic orthostatic hypotension, and may prolong the QTc interval. Pimavanserin was approved by the US Food and Drug Administration (FDA) in 2016 and remains the only FDA-approved medication available to treat hallucinations and delusions associated with PDP. However, pimavanserin can increase QTc interval by approximately 5-8 ms. The potential for QTc prolongation should be considered in patients with symptomatic cardiac arrhythmias and those receiving QT-prolonging medications. In choosing a medication to treat PDP, expected efficacy must be balanced with potential safety concerns for individual patients.

Open channel block of Kv1.4 potassium channels by aripiprazole

Aripiprazole is a quinolinone derivative approved as an atypical antipsychotic drug for the treatment of schizophrenia and bipolar disorder. It acts as with partial agonist activities at the dopamine D2 receptors. Although it is known to be relatively safe for patients with cardiac ailments, less is known about the effect of aripiprazole on voltage-gated ion channels such as transient A-type K⁺ channels, which are important for the repolarization of cardiac and neuronal action potentials. Here, we investigated the effects of aripiprazole on Kv1.4 currents expressed in HEK293 cells using a whole-cell patch-clamp technique. Aripiprazole blocked Kv1.4 channels in a concentration-dependent manner with an IC₅₀ value of 4.4 μM and a Hill coefficient of 2.5. Aripiprazole also accelerated the activation (time-to-peak) and inactivation kinetics. Aripiprazole induced a voltage-dependent (δ = 0.17) inhibition, which was use-dependent with successive pulses on Kv1.4 currents without altering the time course of recovery from inactivation. Dehydroaripiprazole, an active metabolite of aripiprazole, inhibited Kv1.4 with an IC₅₀ value of 6.3 μM (p < 0.05 compared with aripiprazole) with a Hill coefficient of 2.0. Furthermore, aripiprazole inhibited Kv4.3 currents to a similar extent in a concentration-dependent manner with an IC₅₀ value of 4.9 μM and a Hill coefficient of 2.3. Thus, our results indicate that aripiprazole blocked Kv1.4 by preferentially binding to the open state of the channels.

Ventricular Arrhythmia during Tracheal Intubation and Extubation under General Anesthesia Possibly Induced by Amisulpride: A Case Report

We are presenting the first documented case of amisulpride related ventricular arrhythmia during tracheal intubation and extubation under general anesthesia in an 48 year-old female with psychiatric history of chronic schizophrenia who was treated with amisulpride. This case suggests the threshold of perioperative arrhythmia is possibly decreased in patients with long-term antipsychotic medication. So, the potential risk of antipsychotics-induced perioperative arrhythmia should be evaluated, as well as heart rhythm monitoring, prophylactic use of antiarrhythmic drugs, and preoperative adjustment of antipsychotics should be considered.

Change and dispersion of QT interval during treatment with quetiapine extended release versus aripiprazole in children and adolescents with first-episode psychosis: results from the TEA trial

OBJECTIVE

The aim of this study was to compare the effect of quetiapine extended release (ER) versus aripiprazole on corrected QT interval (QTc) and QT dispersion (QTd) in youths with first-episode psychosis.

METHODS

Youths 12-17 years were randomized to quetiapine ER (daily dose range = 50 to 800 mg) or aripiprazole (daily dose range = 2.5 to 30 mg) in a 12-week double-blinded trial and examined at weeks 0, 4, and 12. Primary outcome was QTc change using Hodges formula (QTcH); secondary outcomes included QTcH > 450 ms, QTcH > 500 ms, QTcH change > 60 ms, QTd, and heart rate (HR).

RESULTS

Among 113 randomized youths, follow-up ECG was available for 93 patients (82.3%) (age = 15.8 ± 1.3 years, males = 34.4%, schizophrenia = 67.7%). Quetiapine ER treatment (n = 47) was associated with a significant increase in QTcH of + 6.8 ± 20.2 ms (p = 0.025), while the change from baseline in patients receiving aripiprazole (n = 46) was non-significant (- 3.4 ± 18.9 ms, p = 0.225). One patient in the quetiapine ER group had a QTcH change of + 62.3 ms. Age, sex, smoking, body mass index, and concomitant medication were not significantly associated with QTcH change, but higher baseline potassium was correlated to higher QTcH change in the quetiapine ER group. The HR increased significantly with quetiapine ER (+ 11.0 ± 14.2 bpm, p < 0.001) but not with aripiprazole (- 0.8 ± 12.0 bpm, p = 0.643). QTd did not significantly change with quetiapine ER or aripiprazole.

CONCLUSION

QTcH and HR increased significantly with quetiapine ER, although changes were small and likely not clinically significant in otherwise healthy patients. QTcH and HR were unchanged with aripiprazole. No significant change in QTd was seen. ClinicalTrials.gov: NCT01119014, EudraCT: 2009-016715-38.

Magnesium in schizophrenia

Many psychopathological symptoms, including schizophrenia, can be associated with magnesium metabolism disturbances. In the literature, contradictory data exist regarding magnesium levels in patients with this disorder. However, this situation might be caused by determination of extracellular concentration of magnesium; although, this is mainly an intracellular ion. There are no data concerning determination of the ionized fraction of magnesium in patients with schizophrenia, while the ionized fraction represents 67% of the total pool of magnesium in healthy people. Also, the mechanism of magnesium action-the effect of magnesium ions on NMDA and GABA receptors-has not yet been fully investigated. There are preliminary studies aimed at increasing the effectiveness of schizophrenia pharmacotherapy via magnesium supplementation. Multidirectional activity of magnesium can significantly increase its therapeutic effect in psychiatry. This observation is confirmed by recent studies conducted by various research teams. However, further studies on the role of magnesium supplementation in patients with schizophrenia are needed.

Evaluation of the Relationship Between Pharmacokinetics and the Safety of Aripiprazole and Its Cardiovascular Effects in Healthy Volunteers

AIMS

The aim of this study was the evaluation of the possible relationship between pharmacokinetics and the safety of aripiprazole as well as its influence on blood pressure (BP), heart rate (HR), and corrected QT (QTc) interval.

METHODS

The study population comprised 157 healthy volunteers from 6 bioequivalence clinical trials. Subjects were administered a single 10-mg oral dose of each formulation separated by a 28-day washout period. Plasma concentrations were measured using high-performance liquid chromatography coupled to mass spectrometry. Blood pressure was measured at the following times: predose and 0.5, 2, 4, 6, and 8 hours postdose. An electrocardiogram was recorded at predose, 4, and 8 hours postdose.

RESULTS

Area under the curve (AUC), maximum plasma concentration, half-life, and distribution volume corrected for weight were higher in women. Aripiprazole treatment produced a decrease of BP (9.3 mm Hg on systolic and 6.2 mm Hg on diastolic pressure) and an increase in HR (12.1 beats per minute) and QTc interval (9.1 milliseconds). There were sex differences in BP, HR, and QTc interval. Women and subjects with higher AUC and maximum plasma concentration values were more prone to experience adverse drug reactions and gastrointestinal adverse reactions. The AUC was related with systolic BP and diastolic BP decrease and HR increase but there was no relationship between aripiprazole concentrations and QTc increase.

CONCLUSIONS

Aripiprazole decreases BP and increases HR and QTc interval. Pharmacokinetics, pharmacodynamics, and safety of aripiprazole are affected by sex. There is a directly proportional relationship between pharmacokinetic parameters and adverse drug reactions and effect on BP and HR.

Psychopharmacology of chronic pain: a focus on antidepressants and atypical antipsychotics

Chronic pain is considered one of the most prevalent causes of costly and disabling medical conditions. This review will define chronic pain and its categories and then will summarize the effectiveness and side effects associated with the use of various antidepressants, including the tricyclics, the selective serotonin reuptake inhibitors, the serotonin norepinephrine reuptake inhibitors, other miscellaneous antidepressants and the atypical antipsychotics in the treatment of chronic pain.

Antipsychotics can induce pre-shock in very elderly patients: a report of two cases

Antipsychotics have often been administered to treat delirium and intractable insomnia in elderly patients with or without dementia. However, antipsychotics sometimes cause severe adverse effects. We report two cases of very elderly patients who developed pre-shock after the administration of antipsychotics in a clinical consultation-liaison setting. These cases suggest that antipsychotics can induce fatal adverse events in very elderly patients. Although there has been little evidence regarding the most appropriate kind of drug and dosage for such patients, psychiatrists should exercise great caution in the use of antipsychotics for the very elderly, including deciding to prescribe the lowest dose or not prescribing them at all.

QTc interval prolongation and torsade de pointes associated with second-generation antipsychotics and antidepressants: a comprehensive review

We comprehensively reviewed published literature to determine whether it supported the link between corrected QT (QTc) interval prolongation and torsade de pointes (TdP) for the 11 second-generation antipsychotics and seven second-generation antidepressants commonly implicated in these complications. Using PubMed and EMBASE, we identified four thorough QT studies (one each for iloperidone, ziprasidone, citalopram, and escitalopram), 40 studies specifically designed to assess QTc interval prolongation or TdP, 58 publications based on data from efficacy and safety trials, 18 toxicology studies, and 102 case reports. Thorough QT studies, QTc prolongation-specific studies, and studies based on efficacy and safety trials did not link drug-associated QTc interval prolongation with TdP. They only showed that the drugs reviewed caused varying degrees of QTc interval prolongation, and even that information was not clear and consistent enough to stratify individual drugs for this risk. The few toxicology studies provided valuable information but their findings are pertinent only to situations of drug overdose. Case reports were most informative about the drug-QTc interval prolongation-TdP link. At least one additional well established risk factor for QTc prolongation was present in 92.2 % of case reports. Of the 28 cases of TdP, six (21.4 %) experienced it with QTc interval <500 ms; 75 % of TdP cases occurred at therapeutic doses. There is little evidence that drug-associated QTc interval prolongation by itself is sufficient to predict TdP. Future research needs to improve its precision and broaden its scope to better understand the factors that facilitate or attenuate progression of drug-associated QTc interval prolongation to TdP.

QTc prolongation with antipsychotics: is routine ECG monitoring recommended?

Whether or not QTc interval should be routinely monitored in patients receiving antipsychotics is a controversial issue, given logistic and fiscal dilemmas. There is a link between antipsychotic medications and prolongation of QTc interval, which is associated with an increased risk of torsade de pointes (TdP). Our goal is to provide clinically practical guidelines for monitoring QTc intervals in patients being treated with antipsychotics. We provide an overview of the pathophysiology of the QT interval, its relationship to TdP, and a discussion of the QT prolonging effects of antipsychotics. A literature search for articles relevant to the QTc prolonging effects of antipsychotics and TdP was conducted utilizing the databases PubMed and Embase with various combinations of search words. The overall risk of TdP and sudden death associated with antipsychotics has been observed to be low. Medications, genetics, gender, cardiovascular status, pathological conditions, and electrolyte disturbances have been found to be related to prolongation of the QTc interval. We conclude that, while electrocardiogram (ECG) monitoring is useful when administering antipsychotic medications in the presence of co-existing risk factors, it is not mandatory to perform ECG monitoring as a prerequisite in the absence of cardiac risk factors. An ECG should be performed if the initial evaluation suggests increased cardiac risk or if the antipsychotic to be prescribed has been established to have an increased risk of TdP and sudden death.