Tolcapone 100mg tablets

OBJECTIVE: -methyltransferase (COMT) inhibitor tolcapone constitutes a potentially useful probe of frontal cortical dopaminergic function. The aim of this systematic review was to examine what is known of effects of tolcapone on human cognition in randomized controlled studies. METHODS: The study protocol was preregistered on the Open Science Framework. A systematic review was conducted using PubMed to identify relevant randomized controlled trials examining the effects of tolcapone on human cognition. Identified articles were then screened against inclusion and exclusion criteria. RESULTS: Of the 22 full-text papers identified, 13 randomized control trials were found to fit the pre-specified criteria. The most consistent finding was that tolcapone modulated working memory; however, the direction of effect appeared to be contingent on the COMT polymorphism (more consistent evidence of improvement in Val-Val participants). There were insufficient nature and number of studies for meta-analysis. CONCLUSION: The cognitive improvements identified upon tolcapone administration, in some studies, are likely to be due to the level of dopamine in the prefrontal cortex being shifted closer to its optimum, per an inverted U model of prefrontal function. However, the results should be interpreted cautiously due to the small numbers of studies. Given the centrality of cortical dopamine to understanding human cognition, studies using tolcapone in larger samples and across a broader set of cognitive domains would be valuable. It would also be useful to explore the effects of different dosing regimens (different doses; and single versus repeated administration).

Abstract licence: CC BY-NC-ND

PURPOSE: Tolcapone is an efficacious catechol-O-methyltransferase inhibitor for Parkinson's disease (PD). However, safety issues hampered its use in clinical practice. We aimed to provide evidence of safety and efficacy of tolcapone by a systematic literature review to support clinicians' choices in the use of an enlarging PD therapeutic armamentarium. METHODS: We searched PubMed for studies on PD patients treated with tolcapone, documenting the following outcomes: liver enzyme, adverse events (AEs), daily Off-time, levodopa daily dose, unified Parkinson's disease rating scale (UPDRS) part-III, quality of life (QoL), and non-motor symptoms. FAERS and EudraVigilance databases for suspected AEs were interrogated for potential additional cases of hepatotoxicity. RESULTS: Thirty-two studies were included, for a total of 4780 patients treated with tolcapone. Pertaining safety, 0.9% of patients showed liver enzyme elevation > 2. Over 23 years, we found 7 cases of severe liver injury related to tolcapone, 3 of which were fatal. All fatal cases did not follow the guidelines for liver function monitoring. FAERS and EudraVigilance database search yielded 61 reports of suspected liver AEs possibly related to tolcapone. Pertaining efficacy, the median reduction of hours/day spent in Off was 2.1 (range 1-3.2), of levodopa was 108.9 mg (1-251.5), of "On" UPDRS-III was 3.6 points (1.1-6.5). Most studies reported a significant improvement of QoL and non-motor symptoms. CONCLUSION: Literature data showed the absence of relevant safety concerns of tolcapone when strict adherence to hepatic function monitoring is respected. Given its high efficacy on motor fluctuations, tolcapone is probably an underutilized tool in the therapeutic PD armamentarium.

Abstract licence: CC BY

Alcohol Use Disorder (AUD) is a significant public health issue in the United States. It affects millions of individuals and their families and contributes to substantial societal and economic burdens. Despite the availability of some pharmacological treatments, there is still a pressing need to develop more effective therapeutic strategies to address the diverse range of symptoms and challenges associated with AUD. Catechol-O-methyltransferase (COMT) inhibition recently emerged as a promising new approach to treating AUD due to its potential to improve cognitive effects commonly associated with AUD. Tolcapone, an FDA-approved COMT inhibitor, has shown some promise for treating AUD; however, its ability to decrease drinking in ethanol-dependent rats has not been well-established. In this study, we evaluated the effects of tolcapone on operant, oral ethanol self-administration in non-dependent and dependent rats, and in rats that self-administered oral saccharin. To induce dependence, rats underwent the chronic intermittent exposure to vapor model, and their drinking levels were assessed during acute withdrawal from ethanol. Our results demonstrated that tolcapone attenuated responding for ethanol in dependent rats only, without affecting self-administration in non-dependent rats or rats self-administering saccharin. Moreover, we found that tolcapone was differentially effective in different estrous phases in female rats. These findings suggest that COMT inhibition, specifically using tolcapone, may be a valuable pharmacotherapy for treating AUD, particularly in individuals who are physically dependent on alcohol. Further research is needed to elucidate the precise mechanisms underlying the observed effects and to assess the potential of COMT inhibitors in a broader population of individuals with AUD.

Abstract licence: CC BY