Antioxidants can inhibit basal autophagy and enhance neurodegeneration in models of polyglutamine disease.

Many neurodegenerative diseases exhibit protein accumulation and increased oxidative stress. Therapeutic strategies include clearing aggregate-prone proteins by enhancing autophagy or decreasing oxidative stress with antioxidants. Many autophagy-inducing stimuli increase reactive oxygen species (ROS), raising concerns that the benefits of autophagy up-regulation may be counterbalanced by ROS toxicity. Here we show that not all autophagy inducers significantly increase ROS. However, many antioxidants inhibit both basal and induced autophagy. By blocking autophagy, antioxidant drugs can increase the levels of aggregate-prone proteins associated with neurodegenerative disease. In fly and zebrafish models of Huntington's disease, antioxidants exacerbate the disease phenotype and abrogate the rescue seen with autophagy-inducing agents. Thus, the potential benefits in neurodegenerative diseases of some classes of antioxidants may be compromised by their autophagy-blocking properties

Genetic Analysis of Human Traits In Vitro: Drug Response and Gene Expression in Lymphoblastoid Cell Lines

Lymphoblastoid cell lines (LCLs), originally collected as renewable sources of DNA, are now being used as a model system to study genotype–phenotype relationships in human cells, including searches for QTLs influencing levels of individual mRNAs and responses to drugs and radiation. In the course of attempting to map genes for drug response using 269 LCLs from the International HapMap Project, we evaluated the extent to which biological noise and non-genetic confounders contribute to trait variability in LCLs. While drug responses could be technically well measured on a given day, we observed significant day-to-day variability and substantial correlation to non-genetic confounders, such as baseline growth rates and metabolic state in culture. After correcting for these confounders, we were unable to detect any QTLs with genome-wide significance for drug response. A much higher proportion of variance in mRNA levels may be attributed to non-genetic factors (intra-individual variance—i.e., biological noise, levels of the EBV virus used to transform the cells, ATP levels) than to detectable eQTLs. Finally, in an attempt to improve power, we focused analysis on those genes that had both detectable eQTLs and correlation to drug response; we were unable to detect evidence that eQTL SNPs are convincingly associated with drug response in the model. While LCLs are a promising model for pharmacogenetic experiments, biological noise and in vitro artifacts may reduce power and have the potential to create spurious association due to confounding.Molecular and Cellular Biolog

Prevalence of potentially inappropriate prescribing and prescribing omissions in Irish adults: findings from the Irish LongituDinal Study on Ageing (TILDA)

PURPOSE: We sought to estimate the prevalence of potentially inappropriate prescriptions (PIP) and potential prescribing omissions (PPOs) using a subset of the STOPP/START criteria in a population based sample of Irish adults aged ≥ 65 years using data from The Irish LongituDinal Study on Ageing (TILDA). METHODS: A subset of 26 PIP indicators and 10 PPO indicators from the STOPP/START criteria were applied to the TILDA dataset. PIP/PPO prevalence according to individual STOPP/START criteria and the overall prevalence of PIP/PPO were estimated. The relationship between PIP and PPOs and polypharmacy, age, gender and multimorbidity was examined using logistic regression. RESULTS: The overall prevalence of PIP in the study population (n=3,454) was 14.6 %. The most common examples of PIP identified were NSAID with moderate-severe hypertension (200 participants; 5.8 %) and aspirin with no history of coronary, cerebral, or peripheral vascular symptoms or occlusive event (112 participants; 3.2 %). The overall prevalence of PPOs was 30 % (n=1,035). The most frequent PPO was antihypertensive therapy where systolic blood pressure consistently >160 mmHg (n=341, 9.9 %), There was a significant association between PIP and PPO and polypharmacy when adjusting for age, sex and multimorbidity (adjusted OR 2.62, 95 % CI 2.05-3.33 for PIP and adjusted OR 1.46, 95 % CI 1.23-1.75 for prescribing omissions). CONCLUSION: Our findings indicate prescribing omissions are twice as prevalent as PIP in the elderly using a subset of the STOPP/START criteria as an explicit process measure of potentially inappropriate prescribing and prescribing omissions. Polypharmacy was independently associated with both PPO and PIP. Application of such screening tools to prescribing decisions may reduce unnecessary medication, related adverse events, healthcare utilisation and cost

Can authorities appreciably enhance the prescribing of oral generic risperidone to conserve resources? : findings from across Europe and their implications

Generic atypical antipsychotic drugs offer health authorities opportunities for considerable savings. However, schizophrenia and bipolar disorders are complex diseases that require tailored treatments. Consequently, generally there have been limited demand-side measures by health authorities to encourage the preferential prescribing of generics. This is unlike the situation with hypertension, hypercholaesterolaemia or acid-related stomach disorders.The objectives of this study were to compare the effect of the limited demand-side measures in Western European countries and regions on the subsequent prescribing of risperidone following generics; to utilise the findings to provide future guidance to health authorities; and where possible, to investigate the utilisation of generic versus originator risperidone and the prices for generic risperidone. Principally, this was a segmented regression analysis of retrospective time-series data of the effect of the various initiatives in Belgium, Ireland, Scotland and Sweden following the introduction of generic risperidone. The study included patients prescribed at least one atypical antipsychotic drug up to 20 months before and up to 20 months after generic risperidone. In addition, retrospective observational studies were carried out in Austria and Spain (Catalonia) from 2005 to 2011 as well as one English primary care organisation (Bury Primary Care Trust (PCT)). There was a consistent steady reduction in risperidone as a percentage of total selected atypical antipsychotic utilisation following generics. A similar pattern was seen in Austria and Spain, with stable utilisation in one English PCT. However, there was considerable variation in the utilisation of generic risperidone, ranging from 98% of total risperidone in Scotland to only 14% in Ireland. Similarly, the price of generic risperidone varied considerably. In Scotland, generic risperidone was only 16% of pre-patent loss prices versus 72% in Ireland. Consistent findings of no increased prescribing of risperidone post generics with limited specific demand-side measures suggests no 'spillover' effect from one class to another encouraging the preferential prescribing of generic atypical antipsychotic drugs. This is exacerbated by the complexity of the disease area and differences in the side-effects between treatments. There appeared to be no clinical issues with generic risperidone, and prices inversely reflected measures to enhance their utilisation

Potentially inappropriate prescribing among older people in the United Kingdom

BACKGROUND: Potentially inappropriate prescribing (PIP) in older people is associated with increases in morbidity, hospitalisation and mortality. The objective of this study was to estimate the prevalence of and factors associated with PIP, among those aged ≥70 years, in the United Kingdom, using a comprehensive set of prescribing indicators and comparing these to estimates obtained from a truncated set of the same indicators. METHODS: A retrospective cross-sectional study was carried out in the UK Clinical Practice Research Datalink (CPRD), in 2007. Participants included those aged ≥ 70 years, in CPRD. Fifty-two PIP indicators from the Screening Tool of Older Persons Potentially Inappropriate Prescriptions (STOPP) criteria were applied to data on prescribed drugs and clinical diagnoses. Overall prevalence of PIP and prevalence according to individual STOPP criteria were estimated. The relationship between PIP and polypharmacy (≥4 medications), comorbidity, age, and gender was examined. A truncated, subset of 28 STOPP criteria that were used in two previous studies, were further applied to the data to facilitate comparison. RESULTS: Using 52 indicators, the overall prevalence of PIP in the study population (n = 1,019,491) was 29%. The most common examples of PIP were therapeutic duplication (11.9%), followed by use of aspirin with no indication (11.3%) and inappropriate use of proton pump inhibitors (PPIs) (3.7%). PIP was strongly associated with polypharmacy (Odds Ratio 18.2, 95% Confidence Intervals, 18.0-18.4, P \u3c 0.05). PIP was more common in those aged 70-74 years vs. 85 years or more and in males. Application of the smaller subset of the STOPP criteria resulted in a lower PIP prevalence at 14.9% (95% CIs 14.8-14.9%) (n = 151,598). The most common PIP issues identified with this subset were use of PPIs at maximum dose for \u3e 8 weeks, NSAIDs for \u3e 3 months, and use of long-term neuroleptics. CONCLUSIONS: PIP was prevalent in the UK and increased with polypharmacy. Application of the comprehensive set of STOPP criteria allowed more accurate estimation of PIP compared to the subset of criteria used in previous studies. These findings may provide a focus for targeted interventions to reduce PIP