Analysis of post-market adverse events of istradefylline: a real-world study base on FAERS database.

Analyze the adverse event (AE) signals of istradefylline based on the FAERS database. By extracting large-scale data from the FAERS database, this study used various signal quantification techniques such as ROR, PRR, BCPNN, and MGPS to calculate and evaluate the ratio and association between istradefylline and specific AEs. In the FAERS database, this study extracted data from the third quarter of 2019 to the first quarter of 2023, totaling 6,749,750 AE reports. After data cleansing and drug screening, a total of 3633 AE reports related to istradefylline were included for analysis. Based on four calculation methods, this study unearthed 25 System Organ Class (SOC) AE signals and 82 potential preferred terms (PTs) related to istradefylline. The analysis revealed new AEs during istradefylline treatment, including reports of Parkinsonism hyperpyrexia syndrome (n = 3, ROR 178.70, PRR 178.63, IC 1.97, EBGM 165.63), Compulsions (n = 5, ROR 130.12, PRR 130.04, IC 2.53, EBGM 123.02), Deep brain stimulation (n = 10, ROR 114.42, PRR 114.27, IC 3.33, EBGM 108.83), and Freezing phenomenon (n = 60, ROR 97.52, PRR 96.76, IC 5.21, EBGM 92.83). This study provides new risk signals and important insights into the use of istradefylline, but further research and validation are needed, especially for those AE that may occur in actual usage scenarios but are not yet explicitly described in the instructions.

Methylxanthines and Neurodegenerative Diseases: An Update.

Methylxanthines (MTX) are purine derived xanthine derivatives. Whereas naturally occurring methylxanthines like caffeine, theophylline or theobromine are widely consumed in food, several synthetic but also non-synthetic methylxanthines are used as pharmaceuticals, in particular in treating airway constrictions. Besides the well-established bronchoprotective effects, methylxanthines are also known to have anti-inflammatory and anti-oxidative properties, mediate changes in lipid homeostasis and have neuroprotective effects. Known molecular mechanisms include adenosine receptor antagonism, phosphodiesterase inhibition, effects on the cholinergic system, wnt signaling, histone deacetylase activation and gene regulation. By affecting several pathways associated with neurodegenerative diseases via different pleiotropic mechanisms and due to its moderate side effects, intake of methylxanthines have been suggested to be an interesting approach in dealing with neurodegeneration. Especially in the past years, the impact of methylxanthines in neurodegenerative diseases has been extensively studied and several new aspects have been elucidated. In this review we summarize the findings of methylxanthines linked to Alzheimer´s disease, Parkinson's disease and Multiple Sclerosis since 2017, focusing on epidemiological and clinical studies and addressing the underlying molecular mechanisms in cell culture experiments and animal studies in order to assess the neuroprotective potential of methylxanthines in these diseases.

An evaluation of istradefylline treatment on Parkinsonian motor and cognitive deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated macaque models.

Istradefylline (KW-6002), an adenosine A2A receptor antagonist, is used adjunct with optimal doses of L-3,4-dihydroxyphenylalanine (l-DOPA) to extend on-time in Parkinson's disease (PD) patients experiencing motor fluctuations. Clinical application of istradefylline for the management of other l-DOPA-induced complications, both motor and non-motor related (i.e. dyskinesia and cognitive impairments), remains to be determined. In this study, acute effects of istradefylline (60-100 mg/kg) alone, or with optimal and sub-optimal doses of l-DOPA, were evaluated in two monkey models of PD (i) the gold-standard 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated macaque model of parkinsonian and dyskinetic motor symptoms and (ii) the chronic low dose (CLD) MPTP-treated macaque model of cognitive (working memory and attentional) deficits. Behavioural analyses in l-DOPA-primed MPTP-treated macaques showed that istradefylline alone specifically alleviated postural deficits. When combined with an optimal l-DOPA treatment dose, istradefylline increased on-time, enhanced therapeutic effects on bradykinesia and locomotion, but exacerbated dyskinesia. Istradefylline treatment at specific doses with sub-optimal l-DOPA specifically alleviated bradykinesia. Cognitive assessments in CLD MPTP-treated macaques showed that the attentional and working memory deficits caused by l-DOPA were lowered after istradefylline administration. Taken together, these data support a broader clinical use of istradefylline as an adjunct treatment in PD, where specific treatment combinations can be utilised to manage various l-DOPA-induced complications, which importantly, maintain a desired anti-parkinsonian response.