Exploring the underlying mechanisms of drug-induced impulse control disorders: a pharmacovigilance-pharmacodynamic study

Alexithymia in Parkinson's Disease: A Meta-analysis

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor manifestations, including alexithymia. This condition is defined by difficulty in recognizing, articulating, and expressing one's emotional states. In this study, we conducted a systematic review and meta-analysis to compare the prevalence of alexithymia in PD patients and a healthy population, and to identify associated demographic and clinical factors. We identified 16 observational studies through Pubmed, EMBASE, PsycINFO, and SCOPUS, selecting articles published since 2002. Data were analyzed using a random-effects model. We conducted additional prevalence meta-analyses and correlation meta-analyses. We found that PD patients exhibit higher levels of alexithymia compared to the general population (combined effect size 0.65 [95% CI = 0.49-0.81; P <0.05]), and moderate but significant heterogeneity (I² = 52.42%, Q = 29.42, P <0.05), partially explained by regional differences, levodopa equivalent dosage (positive regression coefficient of 0.0006 [95% CI = 0.0001; 0.0011, P <0.05]); and cognitive scores (negative regression coefficient of -0.14 [95% CI = -0.24; -0.04, P<0.05]), after adjusting for covariates. The additional meta-analysis reported higher prevalence of alexithymia in PD and a pooled correlation coefficient of 0.496 (95% CI = 0.40-0.59, P <0.05) when we analyzed alexithymia and depression scores. To our knowledge, there are no previous meta-analysis applied to alexithymia in PD patients. Even though we could not determine whether alexithymia is a primary characteristic of PD, we found an association of higher levels of alexithymia with depression and higher levodopa equivalent daily dose. Furthermore, there are not enough studies to draw clear conclusions about the influence of cognitive status.

Excessive Daytime Sleepiness as a Risk Factor for Impulse Control Disorders in Parkinson's Disease

Purpose

Impulse control disorders (ICDs) and excessive daytime sleepiness (EDS) are common symptoms in Parkinson's disease (PD). Few longitudinal studies have focused on the association between EDS and ICDs. This longitudinal study aimed at assessing association between EDS and ICDs in PD.

Patients and Methods

Patients without ICDs were incorporated from the Parkinson's Progression Markers Initiative. All patients were followed until the onset of ICDs or the end of 4 years. A total of 260 PD patients were included. Univariable and multivariable logistic regression were used to explore association between EDS and ICDs.

Results

The overall frequency of ICDs at the end of follow-up was 23.8% (62 patients). The mean duration from dopamine replacement therapy to develop ICDs was 3.30 ± 2.42 years. Patients with ICDs had significantly higher Epworth Sleepiness Scale (ESS) score (P = 0.002) and higher proportion of EDS (P = 0.030) when compared to patients without ICDs. The multivariable logistic regression analysis indicated that high ESS (OR = 2.01, 95% CI 1.01-4.04, p = 0.049) score, high dopamine agonist equivalent daily dose (OR = 2.54, 95% CI 1.37-4.71, p = 0.003), high Geriatric Depression Scale (OR = 2.33, 95% CI 1.27-4.28, p = 0.006) score and postural instability (OR = 3.03, 95% CI 1.26-7.29, p = 0.013) were associated with ICDs occurrence.

Conclusion

Our results indicated that EDS acts as a risk for ICDs occurrence in PD. Clinicians should pay attention to EDS in clinical practice. This may be a promising new approach to better understand and therapy ICDs.

Hepatotoxicity of antipsychotics: an exploratory pharmacoepidemiologic and pharmacodynamic study integrating FAERS data and in vitro receptor-binding affinities

Introduction

Antipsychotic psychopharmacotherapy is associated with the risk of drug-induced liver injury (DILI). However, understanding specific risk factors remains challenging due to limited data. This study investigates the relationship between receptor binding affinities and occupancies of antipsychotics and their associated hepatotoxic risks.

Methods

A disproportionality analysis with calculation of the Reporting Odds Ratio (ROR) and the Information Component (IC) was conducted using data from the FDA Adverse Event Reporting System (FAERS) to identify signals related to the Standardised MedDRA Query "drug-related hepatic disorders", which served as a proxy for drug-induced hepatotoxicity. This was followed by a pharmacoepidemiologic-pharmacodynamic approach to investigate the relationship between the ROR and substance-related receptor binding affinities and occupancy, which was estimated based on in vitro receptor-binding profiles.

Results

Significant signals were identified for several antipsychotics, including chlorpromazine, loxapine, olanzapine, and quetiapine, with chlorpromazine and loxapine showing the highest RORs for DILI. Gender-specific analysis revealed a higher frequency of signals in female patients. Statistically significant negative correlations were identified between the ROR for drug-related hepatic disorders and the affinity for serotonin receptor 5-HT1A (r (17) = -0.68, p = 0.0012), while a positive correlation was observed for cholinergic receptors (r (17) = 0.46, p = 0.048). No significant correlations were found related to other receptors or drug properties.

Conclusion

Our findings suggest that the serotonin and probably the cholinergic system may play a role in the development of DILI related to antipsychotic medications. The identification of antipsychotics with a higher association with DILI, such as chlorpromazine, underscores the need for careful monitoring in clinical practice. However, our findings need further longitudinal studies to confirm causality. A better understanding of the associations may inform clinical decision-making, particularly in patients with an increased susceptibility to liver damage.

The atypical antipsychotics and sexual dysfunction: a pharmacovigilance-pharmacodynamic study

Background

Atypical antipsychotics (AAPs)-induced sexual dysfunction (SD) is a frequent issue in clinical practice, often underestimated by clinicians and not extensively researched. The current study aimed to quantify the strength of association between the use of different AAPs and SD using real-world data from the FDA Adverse Event Reporting System (FAERS), as well as investigate the receptor mechanisms that are involved.

Methods

Data from the FAERS database from the first quarter of 2004 to the third quarter of 2023 were queried through OpenVigil 2.1. Disproportionality analysis was estimated using the reporting odds ratio (ROR) and information component (IC) methods, and linear regression was used to investigate the relationship between ROR and receptor occupancy which was estimated using in vitro receptor binding profiles.

Results

Our analysis yielded 4839 reports that co-mentioned AAP and SD events, and the findings revealed statistical associations between 12 AAPs and SD. The highest signal value was identified for iloperidone reporting retrograde ejaculation with iloperidone (ROR = 832.09, ROR025 = 552.77; IC = 9.58, IC025 = 6.36), followed by compulsive sexual behavior with aripiprazole (ROR = 533.02, ROR025 = 435.90; IC = 7.30, IC025 = 5.97), and psychosexual disorder for aripiprazole (ROR = 145.80, ROR025 = 109.57; IC025 = 6.47, IC025 = 4.86). Different characteristics of the SD side effects in each AAPs were discovered after further data mining. Regression analysis revealed potential effects for receptor occupancy of D2, D3, and 5-HT1A receptors on ROR. However, no significant correlation persisted following sensitivity analyses.

Conclusion

This is the first study to investigate the AAP-SD associations by using FAERS. In this study, we report for the first time a significant association between aripiprazole and SD based on real-world data. The study suggests that different AAPs have varying levels of association with SD, and the D2, D3, and 5-HT1A receptor occupancy may contribute to potential mechanisms. The findings of this study warrant further validation of more studies and clinical causality assessment.

Impulse Control Disorders in Parkinson's Disease: An Overview of Risk Factors, Pathogenesis and Pharmacological Management

Impulse control disorders in Parkinson's disease are relatively common drug-induced addictive behaviours that are usually triggered by the dopamine agonists pramipexole, ropinirole and rotigotine. This narrative review aimed to provide a comprehensive overview of the current knowledge of impulse control disorders in Parkinson's disease. We summarised the prevalence, clinical features, risk factors and potential underlying mechanisms of impulse control disorders in Parkinson's disease. Moreover, recent advances in behavioural and imaging characteristics and management strategies are discussed. Early detection as well as a tailored multidisciplinary approach, which typically includes careful adjustment of the dopaminergic therapy and the treatment of associated neuropsychiatric symptoms, are necessary. In some cases, a continuous delivery of levodopa via a pump or the dopamine D1 receptor agonist, apomorphine, can be considered. In selected patients without cognitive or speech impairment, deep brain stimulation of the subthalamic nucleus can also improve addictions. Finding the right balance of tapering dopaminergic dose (usually dopamine agonists) without worsening motor symptoms is essential for a beneficial long-term outcome.

The REporting of A Disproportionality Analysis for DrUg Safety Signal Detection Using Individual Case Safety Reports in PharmacoVigilance (READUS-PV): Explanation and Elaboration

In pharmacovigilance, disproportionality analyses based on individual case safety reports are widely used to detect safety signals. Unfortunately, publishing disproportionality analyses lacks specific guidelines, often leading to incomplete and ambiguous reporting, and carries the risk of incorrect conclusions when data are not placed in the correct context. The REporting of A Disproportionality analysis for drUg Safety signal detection using individual case safety reports in PharmacoVigilance (READUS-PV) statement was developed to address this issue by promoting transparent and comprehensive reporting of disproportionality studies. While the statement paper explains in greater detail the procedure followed to develop these guidelines, with this explanation paper we present the 14 items retained for READUS-PV guidelines, together with an in-depth explanation of their rationale and bullet points to illustrate their practical implementation. Our primary objective is to foster the adoption of the READUS-PV guidelines among authors, editors, peer reviewers, and readers of disproportionality analyses. Enhancing transparency, completeness, and accuracy of reporting, as well as proper interpretation of their results, READUS-PV guidelines will ultimately facilitate evidence-based decision making in pharmacovigilance.

Altered Impulsivity Across Drug-Naïve Parkinsonism, Isolated Rapid Eye Movement Sleep Behavior Disorder, and Their High-Risk Relatives

OBJECTIVE

To determine multidimensional impulsivity levels across different early stages of α-synucleinopathy.

METHODS

This cross-sectional study investigated motor and decisional impulsivity levels using a panel of computerized tasks among drug-naïve parkinsonism patients, isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD) patients and their first-degree relatives (iRBD-FDRs), and control participants. Trait impulsivity and impulse control behaviors were assessed by self-reported questionnaires.

RESULTS

A total of 27 drug-naïve parkinsonism patients, 157 iRBD patients, 66 iRBD-FDRs, and 82 control participants were recruited. Parkinsonism and iRBD patients had fewer numbers of extracted beads in beads task 1 and 2 (both p < 0.001), and a higher rate of irrational choice in task 1 (p = 0.046) before making decisions, and fewer numbers of pumps of unexploded blue balloons in the balloon analog risk task (p = 0.004) than control participants, indicating a higher level of reflection impulsivity and a lower level of risk taking, respectively. iRBD patients had more no-go errors in the go/no-go task than control participants (padjusted  = 0.036), suggesting a higher level of motor impulsivity. iRBD-FDRs with dream-enactment behaviors had fewer numbers of extracted beads (p = 0.047) in beads task 2 than FDRs without dream-enactment behaviors, suggesting a possible higher level of reflection impulsivity.

INTERPRETATION

A complex construct of altered impulsivity with decreased risk taking, but increased reflection and motor impulsivity, has already occurred at the prodromal and early stages of α-synucleinopathy, which have implications for underlying pathophysiology and clinical management of α-synucleinopathy, especially for impulse control behaviors upon dopaminergic drug treatment. ANN NEUROL 2024;95:544-557.

Aripiprazole and its adverse effects in the form of impulsive-compulsive behaviors: A systematic review of case reports

Aripiprazole is an efficacious treatment for both the positive and negative symptoms of schizophrenia and is also commonly used as a mood stabilizer. It is associated with better tolerability compared with other antipsychotics. However, there are reports of patients who experience problem gambling, hypersexuality, obsessive-compulsive symptoms, and other impulsive and/or compulsive behaviors as a result of aripiprazole administration and/or dosage increase. We aimed to do a systematic review of case reports published in this regard. After screening more than 6000 titles and abstracts in ten scientific search engines, we found 35 related records comprising 59 cases. The majority of cases (n = 42, 71.18%) were male, the mean age was 33.83 years (± 13.40), and the average daily dose of aripiprazole was 11.63 mg (± 6.94). The results of our review showed that the most frequently published impulsivity adverse effect of aripiprazole is gambling, followed by hypersexuality, obsessive-compulsive symptoms/disorder, problem eating, trichotillomania, problem shopping, and kleptomania. These symptoms were experienced both by patients who had previous problems in these areas and those who did not. In the majority of cases, the symptoms appeared within 30 days after aripiprazole administration started and ceased within 30 days of its discontinuation and/or dose decrease. Clinicians should be aware of impulsivity adverse effects, monitor them, and educate both patients and the family about them.

Hypersexuality during treatment with cariprazine in a patient with schizophrenia? A case report

BACKGROUND

Cariprazine is a third-generation antipsychotic with a unique mechanism of action. It functions as a partial agonist with high affinity for dopamine D2 and D3 and serotonin 5-HT1A receptors, an antagonist for 5-HT2A (moderate affinity) and 5-HT2B (high affinity) receptors. It binds to histamine H1 receptors and has a low affinity for 5-HT2C and alpha 1A-adrenergic receptors and no affinity for muscarinic (cholinergic) receptors. Among the troubling side effects, symptoms related to impulse control, such as hypersexuality, pathological gambling, compulsive shopping, compulsive eating etc., have been reported with the use of antipsychotic medications. However, no reports have been published regarding impulse control symptoms associated with cariprazine. We report a case of cariprazine-induced hypersexuality in a patient with schizophrenia, which was resolved by discontinuation of the medication.

CASE PRESENTATION

A 67-year-old Caucasian woman with schizophrenia was admitted to the hospital inpatient unit after she discontinued olanzapine and psychotic symptoms reappeared. Prior to that, she was in remission, taking olanzapine for approximately one year. After discontinuation, she experienced auditory hallucinations with persecutory delusions and became anergic and withdrawn, with blunted affect. Olanzapine was reintroduced, as it was proven successful in her past treatments. However, since there were no changes, especially in negative symptoms, cariprazine was added. Seven days after the introduction of cariprazine, the patient developed compulsive sexual behaviour. Therefore, cariprazine was discontinued, and the hypersexual behaviour was resolved.

CONCLUSIONS

In this case report, we describe hypersexual behaviour that could potentially be induced by cariprazine. As a single case study, conclusions cannot be drawn. Controlled studies are warranted to better determine causality and the significance of this possible side-effect of cariprazine.