Evidence for solanidine as a dietary CYP2D6 biomarker: Significant correlation with risperidone metabolism.

AIMS: The extensive variability in cytochrome P450 2D6 (CYP2D6) metabolism is mainly caused by genetic polymorphisms. However, there is large, unexplained variability in CYP2D6 metabolism within CYP2D6 genotype subgroups. Solanidine, a dietary compound found in potatoes, is a promising phenotype biomarker predicting individual CYP2D6 metabolism. The aim of this study was to investigate the correlation between solanidine metabolism and the CYP2D6-mediated metabolism of risperidone in patients with known CYP2D6 genotypes. METHODS: The study included therapeutic drug monitoring (TDM) data from CYP2D6-genotyped patients treated with risperidone. Risperidone and 9-hydroxyrisperidone levels were determined during TDM, and reprocessing of the respective TDM full-scan high-resolution mass spectrometry files was applied for semi-quantitative measurements of solanidine and five metabolites (M402, M414, M416, M440 and M444). Spearman's tests determined the correlations between solanidine metabolic ratios (MRs) and the 9-hydroxyrisperidone-to-risperidone ratio. RESULTS: A total of 229 patients were included. Highly significant, positive correlationswere observed between all solanidine MRs and the 9-hydroxyrisperidone-to-risperidone ratio (ρ > 0.6, P < .0001). The strongest correlation was observed for the M444-to-solanidine MR in patients with functional CYP2D6 metabolism, i.e., genotype activity scores of 1 and 1.5 (ρ 0.72-0.77, P < .0001). CONCLUSION: The present study shows strong, positive correlations between solanidine metabolism and CYP2D6-mediated risperidone metabolism. The strong correlation within patients carrying CYP2D6 genotypes encoding functional CYP2D6 metabolism suggests that solanidine metabolism may predict individual CYP2D6 metabolism, and hence potentially improve personalized dosing of drugs metabolized by CYP2D6.

Combination Therapy of Long-Acting Injectable Second-Generation Antipsychotics and Oral Antipsychotics: A Retrospective Chart Review and Prescribers' Attitude Survey.

BACKGROUND: Although long-acting injectable antipsychotics (LAI-APs) have been considered as a monotherapeutic option in the maintenance treatment of schizophrenia, it has been recently reported that the combination therapy of LAI-APs and oral antipsychotics (OAPs) is common. METHODS: We conducted a retrospective chart review to examine the situation of the combination therapy of LAI second-generation antipsychotics (LAI-SGAs) and OAPs, and a questionnaire survey to investigate prescribers' attitudes toward the combination therapy. We included patients who received any LAI-SGAs for 1 month or longer and classified them into monotherapy and combination therapy groups. We collected information on age, sex, primary psychiatric diagnosis, and concomitant psychotropic medications. RESULTS: Of the 132 patients, 39 (29.5%) received the combination therapy of LAI-SGAs and OAPs. Long-acting injectable risperidone was significantly associated with receiving the combination therapy compared with LAI aripiprazole. Olanzapine was the most common OAP in combination with LAI-SGAs. Only 8 patients (20.5%) concurrently received the same type of OAPs as LAI-SGAs. More than 60% of the patients received OAP polypharmacy before the initiation of LAI-SGAs. The psychiatrists in charge prescribed LAI-SGAs mainly because of a concern about adherence, and OAPs mainly because of insufficient dose of LAI-SGAs, to patients in the combination therapy group. They estimated that adherence to OAPs in two thirds of the patients in the combination therapy group was 80% or higher. CONCLUSIONS: The present study showed that the combination therapy of LAI-SGAs and OAPs is often conducted in real-world clinical practice. Considering the reason for the introduction of LAI-APs, clinicians should carefully monitor patients' adherence to OAPs concurrently used with LAI-APs.

Dopamine modulates the reward experiences elicited by music.

Understanding how the brain translates a structured sequence of sounds, such as music, into a pleasant and rewarding experience is a fascinating question which may be crucial to better understand the processing of abstract rewards in humans. Previous neuroimaging findings point to a challenging role of the dopaminergic system in music-evoked pleasure. However, there is a lack of direct evidence showing that dopamine function is causally related to the pleasure we experience from music. We addressed this problem through a double blind within-subject pharmacological design in which we directly manipulated dopaminergic synaptic availability while healthy participants (n = 27) were engaged in music listening. We orally administrated to each participant a dopamine precursor (levodopa), a dopamine antagonist (risperidone), and a placebo (lactose) in three different sessions. We demonstrate that levodopa and risperidone led to opposite effects in measures of musical pleasure and motivation: while the dopamine precursor levodopa, compared with placebo, increased the hedonic experience and music-related motivational responses, risperidone led to a reduction of both. This study shows a causal role of dopamine in musical pleasure and indicates that dopaminergic transmission might play different or additive roles than the ones postulated in affective processing so far, particularly in abstract cognitive activities.

The effect of risperidone on reward-related brain activity is robust to drug-induced vascular changes.

Dopamine (DA) mediated brain activity is intimately linked to reward-driven cerebral responses, while aberrant reward processing has been implicated in several psychiatric disorders. fMRI has been a valuable tool in understanding the mechanism by which DA modulators alter reward-driven responses and how they may exert their therapeutic effect. However, the potential effects of a pharmacological compound on aspects of neurovascular coupling may cloud the interpretability of the BOLD contrast. Here, we assess the effects of risperidone on reward driven BOLD signals produced by reward anticipation and outcome, while attempting to control for potential drug effects on regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR). Healthy male volunteers (n = 21) each received a single oral dose of either 0.5 mg, 2 mg of risperidone or placebo in a double-blind, placebo-controlled, randomised, three-period cross-over study design. Participants underwent fMRI scanning while performing the widely used Monetary Incentive Delay (MID) task to assess drug impact on reward function. Measures of CBF (Arterial Spin Labelling) and breath-hold challenge induced BOLD signal changes (as a proxy for CVR) were also acquired and included as covariates. Risperidone produced divergent, dose-dependent effects on separate phases of reward processing, even after controlling for potential nonneuronal influences on the BOLD signal. These data suggest the D2 antagonist risperidone has a wide-ranging influence on DA-mediated reward function independent of nonneuronal factors. We also illustrate that assessment of potential vascular confounds on the BOLD signal may be advantageous when investigating CNS drug action and advocate for the inclusion of these additional measures into future study designs.

The Opioid Interactions of the Antipsychotic Medications Risperidone and Amisulpride in Mice and Their Potential Use in the Treatment of Other Non-Psychotic Medical Conditions.

Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. The opioid epidemic in the USA has highlighted the need for alternative treatments for pain. Following reports on the opioid interactions of various antipsychotic medications, we speculated that the involvement of the opioid system in some of the antipsychotics' mechanism of action may suggest their potential use in the treatment of pain. Risperidone is a neuroleptic with a potent dopamine D2 and serotonin 5-HT2 receptor-blocking activity as well as a high affinity for adrenergic and histamine H1 receptors. Amisulpride is a neuroleptic which selectively blocks dopamine D2 and D3 receptors. Both had a potent antinociceptive effect on ICR mice tested with a tail flick assay. That effect on both medications was antagonized by naloxone, indicating that at least some of the antinociceptive effects were mediated by an opioid mechanism of action. Further investigation found that ß-Funaltrexamine hydrochloride (ß-FNA), naloxonazine, and nor-Binaltorphimine dihydrochloride (nor-BNI) reversed the antinociceptive effect of both risperidone and amisulpride. Naltrindole at a dose that blocked [D-Pen2,D-Pen5]enkephalin (DPDPE, δ analgesia) blocked notably amisplride effect and only partially reversed that of risperidone. Risperidone induced an antinociceptive effect, implying involvement of µ and κ-opioid and δ-opioid mechanisms. Amisulpride-induced antinociception was mediated through selective involvement of all three opioid receptor subtypes. These findings emphasize the need for clinical trials to assess the possibility of extending the spectrum of medications available for the treatment of pain.

Finding Early Improvement Threshold to Predict Response After 8 Weeks of Treatment Using Risperidone in First-Episode Psychosis.

PURPOSE/BACKGROUND: The study aims to assess whether the early response can predict the outcome at the endpoint for the treatment of first-episode psychosis with risperidone and identify the relationship between initial symptom reduction and late response. METHODS/PROCEDURES: A prospective observational study with 4 points follow-up (weeks 2, 3, 4, and 8) was conducted in 48 adult first-episode psychosis patients. Symptoms were quantified by the Positive and Negative Syndrome Scale (PANSS) score. The initial recommended dose was 2 mg of risperidone once daily before sleep. The PANSS score on day 1 (before initiation of drug therapy) was considered as the baseline score. Treatment responses were considered as a reduction of more than 20%, 25%, 30% and 50% from the baseline score on first, second, third, and final follow-up, respectively. Receiver operating characteristic curves were generated for predicting response at the endpoint. FINDINGS/RESULTS: Thirty-one (65%) patients achieved more than 50% reduction (responders) in PANSS score. The mean total PANSS score of the study population after 8 weeks of therapy was found to be 49.77 (95% confidence interval, 46.10-53.43). The mean percentage reduction in PANSS score after 8 weeks of therapy was found to be 52.92% (95% confidence interval, 48.83-57.01). Week 2 response can be taken as the early response (area under the curve = 81.9, P < 0.001). However, the more accurate prediction was possible with week 4 response (area under the curve = 88.7%, P < 0.001). IMPLICATIONS/CONCLUSIONS: Our study suggests that patients with an early response at week 2 are likely to achieve positive response after 8 weeks.

Menstrual Dysfunction in Women With Schizophrenia During Risperidone Maintenance Treatment.

BACKGROUND: A percentage of women patients with schizophrenia may suffer from menstrual dysfunction associated with antipsychotic medication. This study evaluated menstrual dysfunction in women with schizophrenia given maintenance risperidone, and investigated the association between menstrual dysfunction and the duration and dose of risperidone and clinical symptoms. METHODS: The data of 161 women were obtained from the Risperidone Maintenance Treatment in Schizophrenia study, including patients' characteristics, menstrual conditions, and duration and dosage of risperidone. Qualitative data regarding menstrual health were evaluated at baseline (clinical stabilization after 4-8 weeks maintenance treatment with a standard risperidone dose 4-8 mg/d) and follow-up interviews up to 52 weeks. RESULTS: At baseline, 73.2% (119/161) of the patients were eumenorrheic; specific rates of menstrual dysfunction were 14.3% (23/161) irregular menstruation, 6.8% (11/161) oligomenorrhea, and 5.0% (8/161) amenorrhea. At the end of follow-up, 16.0% (19/119) of those with eumenorrhea at baseline reported menstrual dysfunction. During the entire risperidone maintenance treatment, 37.9% (61/161) experienced menstrual dysfunction. The range of onset time from the beginning of risperidone treatment to menstrual dysfunction was 64 to 243 days. Risperidone dose was positively associated with menstrual dysfunction (r = 0.187, P = 0.046). The total Positive and Negative Syndrome Scale score was significantly associated with menstrual dysfunction (r = 0.274, P = 0.001). CONCLUSIONS: Attention should be given to menstrual dysfunction of women with schizophrenia that is an adverse effect of risperidone maintenance treatment. Menstrual dysfunction may occur early or late during maintenance treatment, partly depending on the dose.ClinicalTrials.govidentifier: NCT00848432.

A Double-Blind, Placebo-Controlled Trial of Bupropion Add-on to Olanzapine or Risperidone in Overweight Individuals With Schizophrenia.

BACKGROUND: Weight gain due to antipsychotics is a challenging clinical problem because, to date, no effective pharmacological strategies have been found. Bupropion is often used in people with schizophrenia for smoking cessation and is well tolerated. However, studies on its use as weight loss treatment are scarce. The aim of the study was to examine the effectiveness of bupropion as a single weight loss treatment in overweight individuals maintained on long-term olanzapine or risperidone. METHODS: This randomized, double-blind, placebo-controlled, 8-week study included 26 overweight (body mass index ≥27 kg/m2) individuals with schizophrenia maintained on olanzapine (10-20 mg/d) or risperidone (2-4 mg/d). Participants were randomly allocated to a study group that received bupropion (150-300 mg/d) or to a placebo group. The positive and Negative Syndrome Scale and the Clinical Global Impression-Severity Scale were used to assess severity of psychosis at baseline and end of study (8 weeks). RESULTS: Bupropion addition, but not placebo, was associated with a significant reduction in body weight. Severity of psychotic symptoms was not altered in either group. CONCLUSIONS: The results demonstrate the efficacy of bupropion, compared with placebo, in patients maintained on chronic treatment with olanzapine or risperidone, both known to be major contributors to significant weight gain.

Clozapine-Associated Leukopenia and Agranulocytosis in Western Cape, South Africa: A 3-Year Retrospective Cohort Study.

BACKGROUND: Clozapine may cause life-threatening hematological side effects (HSEs). Hematological side effect incidence data from Sub-Saharan Africa are lacking. Furthermore, clozapine reduces cellular immunity, and it is unknown whether clozapine is a risk factor for tuberculosis or whether HIV is a risk factor for developing HSEs. We assessed the incidence of HSEs in South Africans from the Western Cape Province on clozapine, and the secondary objective was to determine the association of HIV and tuberculosis with clozapine exposure. METHODS: We conducted a 24-week retrospective descriptive study of patients initiated on clozapine between January 2015 and December 2017 using anonymized data from the Provincial Health Data Centre. A control group of patients initiated on risperidone was selected. RESULTS: We identified 23,328 patients and included 5213 who had white blood cell monitoring (n = 1047 clozapine, n = 4166 risperidone). The incidence of leukopenia in patients on clozapine was 0.38% (95% confidence interval [CI], 0.01%-0.76%) measured over a 24-week period and was 0.41% in patients on risperidone (95% CI, 0.21%-0.6%) (P = 0.91). The incidence of agranulocytosis in patients on clozapine was 0.19% (95% CI, 0.00%-0.46%) measured over a 24-week period and was 0.24% in patients on risperidone (95% CI, 0.09%-0.39%) (P = 0.266). HIV-infected patients had a 7.46 times increased risk of developing leukopenia (95% CI, 3.37-16.48; P < 0.01). Patients who developed leukopenia had a 6.24 times increased risk of contracting tuberculosis (95% CI, 1.84-21.11; P < 0.01). CONCLUSIONS: Our incidence of clozapine-induced HSEs was lower than previously reported and not significantly different compared with risperidone. HIV infection was associated with HSEs. Patients with HSEs had an increased risk of developing tuberculosis.

A typical antipsychotic treatment induced gradually expanding white matter alterations in healthy individuals with persistent auditory verbal hallucinations-an artificially controlled pilot study.

OBJECTIVE: The aim of this study was to explore the effects of atypical antipsychotics (AaPs) on brain white matter (WM) tracts in healthy individuals with auditory verbal hallucinations (Hi-AVHs). METHODS: We analyzed neuroimaging, AVH symptoms, and cognitive assessment data obtained from 39 Hi-AVHs who reported being distressed by persistent AVHs and volunteered to receive AaP treatment. We used tract-based spatial statistics (TBSS) and t tests to explore AaP pharmacotherapy effects on AVH symptoms and brain WM alterations in Hi-AVH subjects. RESULTS: TBSS and t tests revealed WM alterations after AaP treatment, relative to pretreatment observations. Although AaPs alleviated AVH symptoms, WM alterations in these subjects expanded over 8 months of AaP treatment, encompassing most major WM tracts by the end of the observation period, including the corpus callosum, arcuate fasciculus, cortico-spinal tracts, anterior commissure, and posterior commissure. CONCLUSIONS: The worsening of AaP-associated WM alterations observed in this study suggest that AaPs may not be a good choice for the treatment of Hi-AVHs despite their ability to alleviate AVHs.

Muscle Tissue as a Surrogate for In Vitro Drug Release Testing of Parenteral Depot Microspheres.

Despite the importance of drug release testing of parenteral depot formulations, the current in vitro methods still require ameliorations in biorelevance. We have investigated here the use of muscle tissue components to better mimic the intramuscular administration. For convenient handling, muscle tissue was used in form of a freeze-dried powder, and a reproducible process of incorporation of tested microspheres to an assembly of muscle tissue of standardized dimensions was successfully developed. Microspheres were prepared from various grades of poly(lactic-co-glycolic acid) (PLGA) or ethyl cellulose, entrapping flurbiprofen, lidocaine, or risperidone. The deposition of microspheres in the muscle tissue or addition of only isolated lipids into the medium accelerated the release rate of all model drugs from microspheres prepared from ester-terminated PLGA grades and ethyl cellulose, however, not from the acid-terminated PLGA grades. The addition of lipids into the release medium increased the solubility of all model drugs; nonetheless, also interactions of the lipids with the polymer matrix (ad- and absorption) might be responsible for the faster drug release. As the in vivo drug release from implants is also often faster than in simple buffers in vitro, these findings suggest that interactions with the tissue lipids may play an important role in these still unexplained observations.

Determining the release kinetics of risperidone controlled release matrices to treat schizophrenia.

Risperidone is an atypical antipsychotic agent clinically used to treat schizophrenia, bipolar diseases, and autism. Usually, the frequency of doses is twice daily. In the present study, risperidone controlled release matrices formulated using hydrophilic and hydrophobic polymers. The tablets were prepared by direct compression. The pre-compression and post-compression properties were assessed, along with swelling studies. The morphology of particles observed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The stability study on the drug was performed using thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). The optimized formulation was prepared with the help of hydrophilic polymer K100M (40% ratio). Furthermore, release kinetics had investigated. The release pattern of optimized formulation FT5 fitted best to zero-order kinetics and showed excellent release characteristics. The model-independent approach had been used, formulations FT6 and FT8 showed resemblance with FT5 in all three media, respectively. The once daily formulation of risperidone could be beneficial for schizophrenia patients and their caregivers and will improve patient compliance.

Risperidone and 5-HT2A Receptor Antagonists Attenuate and Reverse Cocaine-Induced Hyperthermia in Rats.

BACKGROUND: Cocaine (benzoylmethylecgonine) is one of the most widely used illegal psychostimulant drugs worldwide, and mortality from acute intoxication is increasing. Suppressing hyperthermia is effective in reducing cocaine-related mortality, but a definitive therapy has not yet been found. In this study, we assessed the ability of risperidone to attenuate acute cocaine-induced hyperthermia and delineated the mechanism of its action. METHODS: Rats were injected i.p. with saline, risperidone, ketanserin, ritanserin, haloperidol, or SCH 23 390 before and after injection of cocaine (30 mg/kg) or with WAY-00 635, SB 206 553, or sulpiride before cocaine injection; thereafter, the rectal temperature was measured every 30 minutes for up to 4 hours. In vivo microdialysis was used to reveal the effect of risperidone on cocaine-induced elevation of dopamine (DA), serotonin (5-HT), and noradrenaline concentrations in the anterior hypothalamus. For post-administration experiments, saline or risperidone (0.5 mg/kg) were injected into rats, and cocaine (30 mg/kg) was injected 15 minutes later. For every 30 minutes thereafter, DA, 5-HT, and noradrenaline levels were measured for up to 240 minutes after cocaine administration. RESULTS: Risperidone, 5-HT2A receptor antagonists, and D1 receptor antagonistic drugs prevented and reversed cocaine-induced hyperthermia. In contrast, receptor antagonists for 5-HT1A, 5-HT2B/2C, and D2 did not alter cocaine-induced hyperthermia. Risperidone treatment further attenuated cocaine-induced elevation of DA. CONCLUSIONS: Our results indicate that risperidone attenuates cocaine-induced hyperthermia primarily by blocking the activities of the 5-HT2A and D1 receptors and may be potentially useful for treating cocaine-induced acute hyperthermia in humans.

Resveratrol Adjunct Therapy for Negative Symptoms in Patients With Stable Schizophrenia: A Double-Blind, Randomized Placebo-Controlled Trial.

BACKGROUND: Patients with schizophrenia can generally manifest a broad variety of primary negative symptoms. The current study aimed to assess the efficacy and tolerability of resveratrol add-on therapy in the treatment of negative symptoms in patients with stable schizophrenia. METHODS: In a randomized, double-blind, and placebo-controlled setting, schizophrenia patients were assigned to receive either 200 mg/d resveratrol or matched placebo in addition to a stable dose of risperidone for 8 weeks. Patients were assessed using the positive and negative syndrome scale, the extrapyramidal symptom rating scale, and Hamilton Depression Rating Scale over the trial period. The primary outcome was considered as the change in positive and negative subscale score from baseline to week 8 between the treatment arms. RESULTS: A total 52 patients completed the trial (26 in each arm). Baseline characteristics of both groups were statistically similar (P > .05). Despite the statistically similar behavior of positive symptoms between the groups across time (Greenhouse-Geisser corrected: F = 1.76, df = 1.88, P = .180), the resveratrol group demonstrated greater improvement in negative, general psychopathology, and total scores (Greenhouse-Geisser corrected: F = 12.25, df = 2.04, P < .001; F = 5.42, df = 1.56, P = .011; F = 7.64, df = 1.48, P = .003). HDRS scores and its changes, ESRS score, and frequency of other complications were not significantly different between resveratrol and placebo groups. CONCLUSION: Adding resveratrol to risperidone can exhibit remarkable efficacy and safety in terms of management of schizophrenia-related negative symptoms.

Antipsychotic Treatment Effectiveness in First Episode of Psychosis: PAFIP 3-Year Follow-Up Randomized Clinical Trials Comparing Haloperidol, Olanzapine, Risperidone, Aripiprazole, Quetiapine, and Ziprasidone.

BACKGROUND: Different effectiveness profiles among antipsychotics may be a key point to optimize treatment in patients suffering a first episode of psychosis to impact on long-term outcome. The aim of this study is to compare the clinical effectiveness of olanzapine, risperidone, haloperidol, aripiprazole, ziprasidone, and quetiapine in the treatment of first episode of psychosis at 3-year follow-up. METHOD: From February 2001 to January 2011, 2 phases of a prospective, randomized, open-label study were undertaken. A total of 376 first-episode drug-naïve patients were randomly assigned to olanzapine (n = 55), risperidone (n = 63), haloperidol (n = 56), aripiprazole (n = 78), ziprasidone (n = 62), or quetiapine (n = 62) and followed up for 3 years. The primary effectiveness measure was all cause of treatment discontinuation. In addition, an analysis based on intention-to-treat principle was conducted in the analysis for clinical efficacy. RESULTS: The overall dropout rate at 3 years reached 20.75%. Treatment discontinuation rates were significantly different among treatment groups (olanzapine = 69.09, risperidone = 71.43, aripiprazole = 73.08%, ziprasidone = 79.03%, haloperidol = 89.28%, and quetiapine = 95.53%) (χ2 = 79.86; P = .000). Statistically significant differences in terms of lack of efficacy, adherence, and tolerability were observed among treatment groups along the 3-year follow-up, determining significant differences in time to all-cause discontinuation (log-rank = 92.240; P = .000). Significant differences between treatments were found in the categories of sleepiness/sedation, increased sleep duration, akinesia, weight gain, ejaculatory dysfunction, extrapyramidal-symptoms, and amenorrhea. CONCLUSIONS: Olanzapine, risperidone, and aripiprazole presented advantages for the first-line treatment of first episode of psychosis in terms of effectiveness. Identifying different discontinuation patterns may contribute to optimize treatment selection after first episode of psychosis.ClinicalTrials.gov Identifier: NCT02526030 https://clinicaltrials.gov/show/NCT02526030.

Trends in the Use of Long-Acting Injectable Antipsychotics in the Province of Manitoba, Canada.

BACKGROUND: Long-acting injectable antipsychotics (LAIAs) have advantages over oral antipsychotics but are not widely used. We aimed to evaluate the impact of market entry of second-generation LAIAs on prescribing trends. METHODS: We used administrative health databases to describe trends in LAIA use from 1995 to 2015 in the Canadian province of Manitoba. Age- and sex-specific incident and prevalent use were determined using prescription dispensation records for the entire population. We used interrupted time series analysis with Poisson regression to estimate change in LAIA use attributable to the market entry of the second-generation LAIA risperidone. RESULTS: We observed 3380 prevalent LAIA users and 2375 incident users in our cohort. Long-acting injectable antipsychotic use was higher in males. Incidence proportions declined from 21.5 users per 100,000 in 1996 to 4.8 in 2004 and then climbed to 14.7 by 2015. First-generation LAIA use peaked at 94.6 prevalent users per 100,000 in 1998 but fell to 40.9 in 2015. Long-acting injectable antipsychotic use increased 1.4% per quarter after the market entry of risperidone long-acting injectable. CONCLUSIONS: Risperidone risperidone long-acting injectable market entry had a positive impact on LAIA prescribing.

Risperidone alone did not induce torsade de pointes: Experimental evidence from the chronic atrioventricular block model dogs.

We assessed torsadogenic action of risperidone, which can potently inhibit IKr as well as α1-adrenoceptor. A toxic dose of 3 mg/kg of risperidone was intravenously administered over 10 min to chronic atrioventricular block dogs without anesthesia with monitoring Holter electrocardiogram (n = 4). Risperidone increased atrial/ventricular rate for 1-12 h/1-6 h and prolonged QTcF at 6 h after its administration, whereas it did not increase short-term variability of repolarization or induced torsade de pointes. These results suggest that α1-adrenoceptor blockade-dependent, hypotension-induced, reflex-mediated increase of sympathetic tone by risperidone might play a role in protecting the heart from IKr inhibition-associated torsade de pointes.

An Evaluation of Risperidone Dosing for Pediatric Delirium in Children Less Than or Equal to 2 Years of Age.

Background: Risperidone dosing and safety data are limited in patients ≤2 years of age. Objective: To describe the dosing strategies, safety, and tolerability of risperidone in infants ≤2 years of age. Methods: An institutional review board-approved retrospective study was conducted in a 24-bed pediatric intensive care unit at an academic medical center in patients ≤2 years of age receiving risperidone for the management of ICU delirium. The primary outcome was mean initial daily dose of risperidone. Secondary outcomes included mean daily dose, dosing frequency, treatment duration, and adverse effects. Results: Seventeen patients who received at least 1 dose of risperidone were included in the study. The initial daily dose ranged from 0.1 to 0.25 mg (0.01-0.04 mg/kg), with a mean of 0.17 mg (0.02 mg/kg). Most patients were initiated on once-daily dosing (76.5%) versus twice-daily dosing (17.6%). More than 80% of patients required a dose increase during therapy. Median daily doses of fentanyl, morphine, ketamine, and midazolam were decreased following initiation of risperidone. No adverse events that led to discontinuation of risperidone were reported. Conclusion and Relevance: Risperidone was found to be safe and well tolerated at daily doses of risperidone of 0.1 to 0.25 mg in 1 or 2 doses per day in patients ≤2 years old for the management of ICU delirium. To our knowledge, these results provide the largest cohort describing dosing recommendations specific for risperidone in this age group. Further investigation on the effect of antipsychotic administration on other sedation and analgesic regimens is necessary.

Chronic Atypical Antipsychotic Use Is Associated With Reduced Need for Postoperative Nausea and Vomiting Rescue in the Postanesthesia Care Unit: A Propensity-Matched Retrospective Observational Study.

BACKGROUND: Atypical antipsychotics are efficacious for chemoprophylaxis against chemotherapy-induced nausea and vomiting, but perioperative investigations have been scant. We sought to examine the association between chronic atypical antipsychotic therapy and the likelihood of postoperative nausea and vomiting. METHODS: In this single-center, propensity-matched, retrospective, observational study, elective noncardiac surgical cases from January 2014 to December 2017 were examined with regard to the primary outcome of rescue antiemetic administration in the postanesthesia care unit as a measure of postoperative nausea and vomiting. Chronic administration of olanzapine, aripiprazole, and risperidone was the exposure of interest. Other independent variables included outpatient antiemetics, modified Apfel score, age, American Society of Anesthesiologists physical status score, case length, and exposures to emetogenic and chemoprophylactic agents. Logistic regression was performed using case-level data. Conditional logistic regression was performed after 1:2 propensity matching, sampling without replacement. Monte Carlo simulation was performed to compute the mean patient-level treatment effect on the treated. RESULTS: Of 13,660 cases, 154 cases with patients receiving atypical antipsychotics were matched against 308 cases without, representing 115 and 273 unique patients, respectively. In a well-balanced cohort, the mean patient-level odds of being administered rescue antiemetic was lower for patients chronically taking the 3 atypical antipsychotics under consideration as compared to those not on atypical antipsychotics, with an odds ratio of 0.29 (95% CI, 0.11-0.75; P = .015). CONCLUSIONS: Chronic atypical antipsychotic therapy is associated with reduced risk of postanesthesia care unit antiemetic administration. These findings support the need for prospective studies to establish the safety and efficacy of postoperative nausea and vomiting chemoprophylaxis with these agents.

Switching to Lurasidone following 12 months of treatment with Risperidone: results of a 6-month, open-label study.

BACKGROUND: Patients with a diagnosis of schizophrenia are at an increased risk for developing metabolic syndrome, which is associated with greater cardiovascular morbidity and mortality. Treatment with some commonly used antipsychotic medications may increase the risk of developing metabolic syndrome. The aim of the study was to evaluate the safety of lurasidone in patients who continued lurasidone or switched from risperidone to lurasidone. A secondary aim was assessment of the effect of long-term lurasidone on the Positive and Negative Syndrome Scale (PANSS). METHODS: The treatment sample in the current study consisted of clinically stable patients with schizophrenia (N = 223) who had completed a 12-month, double-blind study of lurasidone vs. risperidone. In the current extension study, all patients received 6 months of open-label treatment with lurasidone, either continuing lurasidone assigned during the preceding double-blind trial, or switching from double-blind risperidone to lurasidone. Safety and tolerability parameters included body weight, prolactin, and metabolic laboratory tests. RESULTS: Six months of OL treatment with lurasidone was generally well-tolerated, with a low incidence of parkinsonism (4.5%) and akathisia (3.1%). Overall, few adverse events were rated as severe (4.9%), and discontinuation due to an adverse event was low in the lurasidone continuation vs. risperidone switch groups (3.7% vs. 6.9%). In the lurasidone continuation versus risperidone switch groups, change from OL baseline to 6-month endpoint (observed case) was observed in mean body weight (- 0.6 vs. -2.6 kg), median total cholesterol (- 4.0 vs. + 4.5 mg/dL), triglycerides (- 4.5 vs. -5.5 mg/dL), glucose (0.0 vs. -3.0 mg/dL) and prolactin (males, + 0.15 vs. -11.2 ng/mL; females, + 1.3 vs. -30.8 ng/mL). Improvement in PANSS total score was maintained, from OL baseline to endpoint in the continuation vs. switch groups (+ 1.0 vs. -1.0; OC). CONCLUSIONS: In this 6-month extension study, lurasidone treatment was generally well-tolerated and associated with minimal effects on weight, metabolic parameters, and prolactin levels. Patients who switched from risperidone to lurasidone experienced reductions in weight, metabolic parameters and prolactin levels commensurate with increases in these safety parameters experienced during the previous 12 months of treatment with risperidone. TRIAL REGISTRATION: ClinicalTrials.gov NCT00641745 (Date of Registration: March 24, 2008).