Hepatotoxicity of therapeutic short-course paracetamol in hospital inpatients: impact of ageing and frailty

The Impact of Drugs on Hydrogen Sulfide Homeostasis in Mammals

Mammalian cells and tissues have the capacity to generate hydrogen sulfide gas (H₂S) via catabolic routes involving cysteine metabolism. H₂S acts on cell signaling cascades that are necessary in many biochemical and physiological roles important in the heart, brain, liver, kidney, urogenital tract, and cardiovascular and immune systems of mammals. Diminished levels of this molecule are observed in several pathophysiological conditions including heart disease, diabetes, obesity, and immune function. Interestingly, in the last two decades, it has become apparent that some commonly prescribed pharmacological drugs can impact the expression and activities of enzymes responsible for hydrogen sulfide production in cells and tissues. Therefore, the current review provides an overview of the studies that catalogue key drugs and their impact on hydrogen sulfide production in mammals.

Why paracetamol (acetaminophen) is a suitable first choice for treating mild to moderate acute pain in adults with liver, kidney or cardiovascular disease, gastrointestinal disorders, asthma, or who are older

Acute pain is among the most common reasons that people consult primary care physicians, who must weigh benefits versus risks of analgesics use for each patient. Paracetamol (acetaminophen) is a first-choice analgesic for many adults with mild to moderate acute pain, is generally well tolerated at recommended doses (≤4 g/day) in healthy adults and may be preferable to non-steroidal anti-inflammatory drugs that are associated with undesirable gastrointestinal, renal, and cardiovascular effects. Although paracetamol is widely used, many patients and physicians still have questions about its suitability and dosing, especially for older people or adults with underlying comorbidities, for whom there are limited clinical data or evidence-based guidelines. Inappropriate use may increase the risks of both overdosing and inadequate analgesia. To address knowledge deficits and augment existing guidance in salient areas of uncertainty, we have researched, reviewed, and collated published evidence and expert opinion relevant to the acute use of paracetamol by adults with liver, kidney, or cardiovascular diseases, gastrointestinal disorders, asthma, or/and who are older. A concern is hepatotoxicity, but this is rare among adults who use paracetamol as directed, including people with cirrhotic liver disease. Putative epidemiologic associations of paracetamol use with kidney or cardiovascular disease, hypertension, gastrointestinal disorders, and asthma largely reflect confounding biases and are of doubtful relevance to short-term use (<14 days). Paracetamol is a suitable first-line analgesic for mild to moderate acute pain in many adults with liver, kidney or cardiovascular disease, gastrointestinal disorders, asthma, and/or who are older. No evidence supports routine dose reduction for older people. Rather, dosing for adults who are older and/or have decompensated cirrhosis, advanced kidney failure, or analgesic-induced asthma that is known to be cross-sensitive to paracetamol, should be individualized in consultation with their physician, who may recommend a lower effective dose appropriate to the circumstances.

Nonopioid Analgesics for the Perioperative Geriatric Patient: A Narrative Review

Management of acute perioperative pain in the geriatric patient can be challenging as the physiologic and pharmacokinetic changes associated with aging may predispose older patients to opioid-related side effects. Furthermore, elderly adults are more susceptible to postoperative delirium and postoperative cognitive dysfunction, which may be exacerbated by both poorly controlled postoperative pain and commonly used pain medications. This narrative review summarizes the literature published in the past 10 years for several nonopioid analgesics commonly prescribed to the geriatric patient in the perioperative period. Nonopioid analgesics are broken down as follows: medications prescribed throughout the perioperative period (acetaminophen and nonsteroidal anti-inflammatory drugs), medications limited to the acute perioperative setting (N-methyl-D-aspartate receptor antagonists, dexmedetomidine, dexamethasone, and local anesthetics), and medications to be used with caution in the geriatric patient population (gabapentinoids and muscle relaxants). Our search identified 1757 citations, but only 33 specifically focused on geriatric analgesia. Of these, only 21 were randomized clinical trials' and 1 was a systematic review. While guidance in tailoring pain regimens that focus on the use of nonopioid medications in the geriatric patient is lacking, we summarize the current literature and highlight that some nonopioid medications may extend benefits to the geriatric patient beyond analgesia.

Alterations in drug disposition in older adults: a focus on geriatric syndromes

INTRODUCTION

Age-associated physiological changes can alter the disposition of drugs, however, pathophysiological changes associated with geriatric syndromes in older adults may lead to even greater heterogeneity in pharmacokinetics. Geriatric syndromes are common health problems in older adults which have multifactorial causes and do not fit into distinct organ-based disease categories. With older adults being the greatest users of medications, understanding both age- and geriatric syndrome-related changes is important clinically to ensure safe and effective medication use.

AREAS COVERED

This review provides an overview of current evidence regarding pharmacokinetic alterations that occur with aging and in common geriatric syndromes, including frailty, sarcopenia, dementia, polypharmacy and enteral feeding. The evidence is presented according to the four primary pharmacokinetic processes (Absorption, Distribution, Metabolism and Excretion).

EXPERT OPINION

There is some evidence to inform our understanding of the impact of chronological aging and various geriatric syndromes on drug disposition. However, many areas require more research, including drug induced inhibition and induction of cytochrome P450 enzymes and the clinical utility of emerging methods for estimating renal function. There is a need to develop tools to predict alterations in drug disposition in subgroups of older adults, particularly where the currently available clinical information is sparse.

Frailty in Older Patients with Acute Coronary Syndrome in Vietnam

Background

There has been limited evidence about frailty in older patients with acute coronary syndrome (ACS) in Vietnam.

Aim

(1) To investigate the prevalence of frailty in older patients hospitalised with ACS and its associated factors; (2) To investigate the impact of frailty on percutaneous coronary intervention (PCI) and adverse outcomes in this population.

Methods

Patients aged ≥60 with ACS admitted to two teaching hospitals in Vietnam were recruited from 9/2017 to 4/2018. Frailty was defined by the Reported Edmonton Frail Scale. Multivariate logistic regression was applied to investigate the associated factors of frailty and the impact of frailty on PCI and adverse outcomes.

Results

There were 324 participants, mean age 73.5±8.3, 39.2% female. The prevalence of frailty was 48.1%. Advanced age, female gender, history of hypertension, heart failure, stroke and chronic kidney disease were significantly associated with a frailty status. Overall, 50.3% of the participants received PCI (58.3% in the non-frail vs 41.7% in the frail, p=0.003). However, frailty did not have an independent impact on PCI (adjusted OR 0.66, 95% CI 0.41–1.08). Frailty was significantly associated with increased risk of having arrhythmia during hospitalisation (adjusted OR 2.24, 95% CI 1.32–3.80), hospital-acquired pneumonia (adjusted OR 2.27, 95% CI 1.24–4.17), in-hospital mortality (adjusted OR 3.02, 95% CI 1.35–6.75), 30-day mortality (adjusted OR 3.28, 95% CI 1.59–6.76), and 30-day readmission (adjusted OR 2.53, 95% CI 1.38–4.63).

Conclusion

In this study, frailty was present in nearly half of older patients with ACS and was associated with increased adverse outcomes. These findings suggest that frailty screening should be performed in older patients with ACS in Vietnam.

Hepatotoxicity risk factors and acetaminophen dose adjustment, do prescribers give this issue adequate consideration? A French university hospital study

BACKGROUND

The hepatotoxicity of acetaminophen is recognised worldwide. Unfavourable prognoses relating to overdose include liver transplantation and/or death. Several hepatotoxicity risk factors (HRFs) should motivate the adjustment of acetaminophen daily intake (to < 4 g/day): advanced age, weight < 50 kg, malnutrition, chronic alcoholism, chronic hepatitis B and C and HIV infection, severe chronic renal failure and hepatocellular insufficiency.

METHOD

Over a 7-day period in Rennes University Hospital in December 2017, using DxCare® software, with an odds ratio estimation, we analysed all acetaminophen prescriptions, to assess to what extent the presence of HRFs altered the prescribers' choice of acetaminophen dose (< 4 g/day versus 4 g/day).

RESULTS

Among 1842 patients, considering only the first acetaminophen prescription, 73.7% were on 4 g/day. Almost half this population had at least 1 HRF. Whereas around 80% of the prescriptions in the < 4 g/day group were for patients with at least 1 HFR, only 53% of the prescriptions in the 4 g/day group concerned patients without HFRs (p < 0.001). Age > 75 and low weight were associated with the prescriber's choice of dose. Neither chronic alcoholism nor hepatocellular insufficiency influenced the acetaminophen doses prescribed.

CONCLUSION

Considering the widespread use of acetaminophen and its favourable safety profile compared with other analgesic drugs, it appears urgent to remind prescribers of the maximum daily dose recommendations for acetaminophen for patients with HRFs, especially those with chronic alcoholism and hepatocellular insufficiency.

The impact of frailty on prolonged hospitalization and mortality in elderly inpatients in Vietnam: a comparison between the frailty phenotype and the Reported Edmonton Frail Scale

AIMS

To investigate the impact of frailty on outcomes in older hospitalized patients, including prolonged length of stay and all-cause mortality 6 months after admission, using both the frailty phenotype and the Reported Edmonton Frail Scale (REFS).

PATIENTS AND METHODS

This study is the follow-up phase of a study designed to investigate the prevalence of frailty and its impact on adverse outcomes in older hospitalized patients at the National Geriatric Hospital in Hanoi, Vietnam.

RESULTS

A total of 461 participants were included, with a mean age 76.2±8.9 years, and 56.8% were female. The prevalence of frailty was 31.9% according to the REFS and 35.4% according to Fried's criteria. The kappa coefficient was 0.57 (95% CI =0.49-0.66) between the two frailty criteria in identifying frail and non-frail participants. There was a trend toward increasing the likelihood of prolonged hospitalization in participants with frailty defined by Fried's criteria (adjusted OR =1.49, 95% CI =0.94-2.35) or by REFS (adjusted OR =1.43, 95% CI =0.89-2.29). During 6 months of follow-up, 210 were lost and 18/251 (7.2%) participants died. Mortality was higher in those with frailty defined by either Fried's criteria or REFS. On multivariable survival analysis, adjusted HRs for mortality were 2.65 (95% CI =1.02-6.89) for Fried's criteria and 4.19 (95% CI =1.59-10.99) for REFS.

CONCLUSION

Fried's frailty phenotype or REFS can be used as a screening tool to detect frailty in older inpatients in Vietnam and predict mortality. Frailty screening can help prioritize targeted frailty-tailored treatments, such as nutrition, early mobility and medication review, for these vulnerable patients to improve clinical outcomes.

Paracetamol in Older People: Towards Evidence-Based Dosing?

Paracetamol is the most commonly used analgesic in older people, and is mainly dosed according to empirical dosing guidelines. However, the pharmacokinetics and thereby the effects of paracetamol can be influenced by physiological changes occurring with ageing. To investigate the steps needed to reach more evidence-based paracetamol dosing regimens in older people, we applied the concepts used in the paediatric study decision tree. A search was performed to retrieve studies on paracetamol pharmacokinetics and safety in older people (> 60 years) or studies that performed a (sub) analysis of pharmacokinetics and/or safety in older people. Of 6088 articles identified, 259 articles were retained after title and abstract screening. Further abstract and full-text screening identified 27 studies, of which 20 described pharmacokinetics and seven safety. These studies revealed no changes in absorption with ageing. A decreased (3.9-22.9%) volume of distribution (Vd) in robust older subjects and a further decreased Vd (20.3%) in frail older compared with younger subjects was apparent. Like Vd, age and frailty decreased paracetamol clearance (29-45.7 and 37.5%) compared with younger subjects. Due to limited and heterogeneous evidence, it was difficult to draw firm and meaningful conclusions on changed risk for paracetamol safety in older people. This review is a first step towards bridging knowledge gaps to move to evidence-based paracetamol dosing in older subjects. Remaining knowledge gaps are safety when using therapeutic dosages, pharmacokinetics changes in frail older people, and to what extent changes in paracetamol pharmacokinetics should lead to a change in dosage in frail and robust older people.

What do we know about frailty in the acute care setting? A scoping review

Background

The ability of acute care providers to cope with the influx of frail older patients is increasingly stressed, and changes need to be made to improve care provided to older adults. Our purpose was to conduct a scoping review to map and synthesize the literature addressing frailty in the acute care setting in order to understand how to tackle this challenge. We also aimed to highlight the current gaps in frailty research.

Methods

This scoping review included original research articles with acutely-ill Emergency Medical Services (EMS) or hospitalized older patients who were identified as frail by the authors. We searched Medline, CINAHL, Embase, PsycINFO, Eric, and Cochrane from January 2000 to September 2015.

Results

Our database search initially resulted in 8658 articles and 617 were eligible. In 67% of the articles the authors identified their participants as frail but did not report on how they measured frailty. Among the 204 articles that did measure frailty, the most common disciplines were geriatrics (14%), emergency department (14%), and general medicine (11%). In total, 89 measures were used. This included 13 established tools, used in 51% of the articles, and 35 non-frailty tools, used in 24% of the articles. The most commonly used tools were the Clinical Frailty Scale, the Frailty Index, and the Frailty Phenotype (12% each). Most often (44%) researchers used frailty tools to predict adverse health outcomes. In 74% of the cases frailty predicted the outcome examined, typically mortality and length of stay.

Conclusions

Most studies (83%) were conducted in non-geriatric disciplines and two thirds of the articles identified participants as frail without measuring frailty. There was great variability in tools used and more recently published studies were more likely to use established frailty tools. Overall, frailty appears to be a good predictor of adverse health outcomes. For frailty to be implemented in clinical practice frailty tools should help formulate the care plan and improve shared decision making. How this will happen has yet to be determined.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0823-2) contains supplementary material, which is available to authorized users.

What dose of paracetamol for older people?

Paracetamol, on its own or in combination with other analgesics, is widely used to treat pain associated with acute and chronic conditions. It is considered safe enough to have a general sales licence (GSL) for use by "adults, elderly and children over 16 years" and has few listed cautions or contraindications.1,2 However, recently the effectiveness and safety of paracetamol for some conditions have been challenged, 3,4 and there are published case reports of liver failure associated with therapeutic doses.5-9 Here, we review the use of paracetamol, its pharmacokinetics, the mechanisms by which it can cause liver damage and consider whether frail older people are at greater risk of adverse effects. We also discuss if dose reduction should be considered in some circumstances.

Are some people at increased risk of paracetamol-induced liver injury? A critical review of the literature

Purpose

Paracetamol is one of the world’s most commonly used drugs. In overdose, it is well established to be hepatotoxic. The aim of this review was to identify factors that have been, or actually are, associated with the development of liver injury after paracetamol exposure in humans.

Method

Google Scholar and PubMed were searched on various dates between December 2016 and March 2017. Papers identified had their references analysed for further studies that might be relevant.

Results

At the time of writing, there was little good quality clinical evidence—from studies of paracetamol overdose or therapeutic use—to suggest that any groups of people are relatively protected from, or are at greater risk of, liver injury. The factors that were historically used to indicate higher risk in the UK have no good quality clinical evidence to support their re-introduction into clinical practice. The safe (and still effective) oral dose of paracetamol in patients weighing less than 50 kg has not been established.

Conclusion

There is no patient group that is unequivocally at elevated risk of paracetamol-induced liver toxicity. We propose two clinical scenarios that warrant further research. Firstly, there is a need to establish whether the dose of paracetamol should be reduced in patients with low body weight. Secondly, if or when genomic information regarding individual patients becomes readily available to inform prescribing, we propose the contribution of the genome to paracetamol toxicity should be re-investigated with robustly designed studies. Such studies could enhance the safe use of one of the most frequently taken drugs.

Electronic supplementary material

The online version of this article (10.1007/s00228-017-2356-6) contains supplementary material, which is available to authorized users.

Prevalence of frailty and its associated factors in older hospitalised patients in Vietnam

Background

Frailty is an emerging issue in geriatrics and gerontology. The prevalence of frailty is increasing as the population ages. Like many developing countries, Vietnam has a rapidly ageing population. However, there have been no studies about frailty in older people in Vietnam. This study aims to investigate the prevalence of frailty and its associated factors in older hospitalised patients at the National Geriatric Hospital in Hanoi, Vietnam.

Methods

Prospective observational study in inpatients aged ≥60 years at the National Geriatric Hospital in Hanoi, Vietnam from 4/2015 to 10/2015. Frailty was assessed using the Reported Edmonton Frail Scale (REFS) and Fried frailty phenotype.

Results

A total of 461 patients were recruited (56.8% female, mean age 76.2 ± 8.9 years). The prevalence of frailty was 31.9% according to the REFS. Using the Fried frailty criteria, the percentages of non-frail, pre-frail and frail participants were 24.5, 40.1 and 35.4%, respectively. Factors associated with frailty defined by REFS were age (OR 1.05 per year, 95% CI 1.03–1.08), poor reported nutritional status (OR 4.51, 95% CI 2.15–9.44), and not finishing high school (OR 2.18, 95% CI 1.37–3.46). Factors associated with frailty defined by the Fried frailty criteria included age (OR 1.07 per year, 95% CI 1.05–1.10), poor reported nutritional status (OR 2.96, 95%CI 1.43–6.11), not finishing high school (OR 1.58, 95% CI 1.01–2.46) and cardiovascular disease (OR 1.76, 95% CI 1.16–2.67).

Conclusions

While further studies are needed to examine the impact of frailty on outcomes in Vietnam, the observed high prevalence of frailty in older inpatients is likely to have implications for health policy and planning for the ageing population in Vietnam.

Pain in the Frail or Elderly Patient: Does Tapentadol Have a Role?

Persistent pain affects the elderly disproportionally, occurring in 50% of elderly community-dwelling patients and 80% of aged care residents. The management of pain in the elderly and frail patient is complicated because of the risks posed by changes in pharmacokinetics and pharmacodynamics, polypharmacy, and drug-disease interactions. Trials evaluating the efficacy of analgesics have often excluded elderly patients and universally excluded frail patients; therefore, the true efficacy and side-effect profiles in these population groups are largely unknown, especially for long-term use. A stepwise approach is recommended to managing pain, commencing with paracetamol and adding on opioids when needed to manage pain. However, because of the short duration of clinical trials, exclusion of frail patients, and minimal inclusion of elderly patients, the decision as to which opioid should be added on to paracetamol is a difficult one. This article reviews the evidence surrounding a newer opioid, tapentadol. Tapentadol acts on both the mu receptors and on neuronal reuptake of noradrenaline, and has no significant analgesically active metabolites, which theoretically presents some advantages, particularly in comparison with tramadol. However, the evidence to support tapentadol is weak and the trials were often methodologically poor and sponsored almost universally by the drug company. Currently, there is insufficient evidence to support the use of tapentadol over other opioids, which have been on the market longer, are less expensive, and have better established safety profiles. As a first-line agent after the failure of paracetamol alone, morphine, oxycodone, fentanyl, or buprenorphine are still the preferred evidence-based choices for add-on opioid therapy for elderly or frail patients.

Acetaminophen hepatotoxicity in mice: Effect of age, frailty and exposure type

Acetaminophen is a commonly used analgesic that can cause severe hepatotoxicity in overdose. Despite old age and frailty being associated with extensive and long-term utilization of acetaminophen and a high prevalence of adverse drug reactions, there is limited information on the risks of toxicity from acetaminophen in old age and frailty. This study aimed to assess changes in the risk and mechanisms of hepatotoxicity from acute, chronic and sub-acute acetaminophen exposure with old age and frailty in mice. Young and old male C57BL/6 mice were exposed to either acute (300 mg/kg via oral gavage), chronic (100 mg/kg/day in diet for six weeks) or sub-acute (250 mg/kg, t.i.d., for three days) acetaminophen, or saline control. Pre-dosing mice were scored for the mouse clinical frailty index, and after dosing serum and liver tissue were collected for assessment of toxicity and mechanisms. There were no differences with old age or frailty in the degree of hepatotoxicity induced by acute, chronic or subacute acetaminophen exposure as assessed by serum liver enzymes and histology. Age-related changes in the acetaminophen toxicity pathways included increased liver GSH concentrations, increased NQO1 activity and an increased pro- and anti-inflammatory response to acetaminophen in old age. Frailty-related changes included a negative correlation between frailty index and serum protein, albumin and ALP concentrations for some mouse groups. In conclusion, although there were changes in some pathways that would be expected to influence susceptibility to acetaminophen toxicity, there was no overall increase in acetaminophen hepatotoxicity with old age or frailty in mice.

Drug-induced liver injury in older adults

Drug-induced liver injury (DILI) is an important cause of hospitalisation and of medication deregistration. In old age, susceptibility to DILI is affected by changes in physiology and increased interindividual variability, compounded by an increased prevalence of disease and the frailty syndrome. While dose-related or predictable DILI reactions are often detected in preclinical trials, the occurrence of rare hypersensitivity or idiosyncratic reactions cannot be reliably predicted from preclinical studies or even by clinical trials. The limited participation of older adults in clinical trials means that the susceptibility of this population to DILI is largely unknown. Vigilance during clinical trials and postmarketing surveillance must be universally practised. A systematic approach should be taken to determine not only which medicines are hepatotoxic and should be removed from the market, but also the hepatotoxicity risks from marketed drugs to consumers with different characteristics, many of whom are older people.

Preliminary evaluation of Diopatra neapolitana regenerative capacity as a biomarker for paracetamol exposure

An increasing number of studies established unequivocal relationships between exposure to pharmaceutical drugs and toxicity in wildlife. However, few studies investigated physiological alterations caused by such compounds in polychaetes. Thus, in this study, the effects of increasing concentrations of paracetamol were studied in the polychaete Diopatra neapolitana using tissue regenerative capacity as a biomarker. The obtained results revealed that individuals exposed to ecologically relevant concentrations (namely, 25 μg/L) of paracetamol exhibited significantly lower capacity to regenerate their body in comparison with control organisms. This study evidenced that paracetamol can induce significant physiological alterations in D. neapolitana resulting in an overall diminished regenerative capacity, which is of significance to a species with high ecological and economic relevance. Additionally, this study indicates the promise of D. neapolitana as a test organism in laboratory-based bioassays, but also as an adequate sentinel species to pharmaceutical drugs.

Frailty, mycophenolate reduction, and graft loss in kidney transplant recipients

BACKGROUND

Mycophenolate mofetil (MMF) side effects often prompt dose reduction or discontinuation, and this MMF dose reduction (MDR) can lead to rejection and possibly graft loss. Unfortunately, little is known about what factors might cause or contribute to MDR. Frailty, a measure of physiologic reserve, is emerging as an important, novel domain of risk in kidney transplantation recipients. We hypothesized that frailty, an inflammatory phenotype, might be associated with MDR.

METHODS

We measured frailty (shrinking, weakness, exhaustion, low physical activity, and slowed walking speed), other patient and donor characteristics, longitudinal MMF doses, and graft loss in 525 kidney transplantation recipients. Time-to-MDR was quantified using an adjusted Cox proportional hazards model.

RESULTS

By 2 years after transplantation, 54% of frail recipients and 45% of nonfrail recipients experienced MDR; by 4 years, incidence was 67% and 51%. Frail recipients were 1.29 times (95% confidence interval [95% CI], 1.01-1.66; P = 0.04) more likely to experience MDR, as were deceased donor recipients (adjusted hazard ratio [aHR], 1.92; 95% CI, 1.44-2.54, P < 0.001) and older adults (age ≥ 65 vs <65; aHR, 1.47; 95% CI, 1.10-1.96, P = 0.01). Mycophenolate mofetil dose reduction was independently associated with a substantially increased risk of death-censored graft loss (aHR, 5.24; 95% CI, 1.97-13.98, P = 0.001).

CONCLUSION

A better understanding of risk factors for MMF intolerance might help in planning alternate strategies to maintain adequate immunosuppression and prolong allograft survival.

Non-opiate pharmacotherapy options for the management of pain in older adults

Pain is highly prevalent, costly, and disabling in later life, especially when undertreated. In this article, we aim to describe the risks and benefits of non-opioid medication options for the management of pain in adults aged 65 years and older in order to provide additional options in a practitioner's tool box when designing a pain management regimen for an older adult. Non-opiate pharmacologic therapies, such as acetaminophen, nonsteroidal anti-inflammatory drugs, topicals, and antidepressants have an important role in pain management of older adults. When designing a pain regimen, taking an individualized approach that considers the patient's functional status, comorbidities, and treatment goals will maximize pain management.

Standard laboratory tests to identify older adults at increased risk of death

BACKGROUND

Older adults are at an increased risk of death, but not all people of the same age have the same risk. Many methods identify frail people (that is, those at increased risk) but these often require time-consuming interactions with health care providers. We evaluated whether standard laboratory tests on their own, or added to a clinical frailty index (FI), could improve identification of older adults at increased risk of death.

METHODS

This is a secondary analysis of a prospective cohort study, where community dwelling and institutionalized participants in the Canadian Study of Health and Aging who also volunteered for blood collection (n = 1,013) were followed for up to six years. A standard FI (FI-CSHA) was constructed from data obtained during the clinical evaluation and a second, novel FI was constructed from laboratory data plus systolic and diastolic blood pressure measurements (FI-LAB). A combined FI included all items from each index. Predictive validity was tested using Cox proportional hazards analysis and discriminative ability by the area under receiver operating characteristic (ROC) curves.

RESULTS

Of 1,013 participants, 51.3% had died by six years. The mean baseline value of the FI-LAB was 0.27 (standard deviation 0.11; range 0.05 to 0.63), the FI-CSHA was 0.25 (0.11; 0.02 to 0.72), and the combined FI was 0.26 (0.09; 0.06 to 0.59). In an age- and sex-adjusted model, with each increment in the FI-LAB, the hazard ratios increased by 2.8% (95% confidence interval 1.02 to 1.04). The hazard ratios for the FI-CSHA and the combined FI were 1.02 (1.01 to 1.03) and 1.04 (1.03 to 1.05), respectively. The FI-LAB and FI-CSHA remained independently associated with death in the face of the other. The areas under the ROC curves were 0.72 for FI-LAB, 0.73 for FI-CSHA and 0.74 for the combined FI.

CONCLUSIONS

An FI based on routine laboratory data can identify older adults at increased risk of death. Additional evaluation of this approach in clinical settings is warranted.

A randomized, placebo-controlled trial to determine the course of aminotransferase elevation during prolonged acetaminophen administration

Background

Acetaminophen administration for more than 4 days causes aminotransferase elevation in some subjects. The objective of this randomized, placebo-controlled trial is to describe the course of alanine aminotransferase (ALT) elevation in subjects administered 4 g/day of acetaminophen for at least 16 days.

Methods

A randomized, placebo controlled trial of acetaminophen (4 g/day) vs placebo. Subjects were healthy volunteers with normal liver enzymes. The primary outcome was the course of ALT during acetaminophen administration. All subjects were treated for a minimum of 16 days. Subjects with ALT elevation at day 16 were continued on treatment until these elevations resolved up to a maximum of 40 days. Subjects were also evaluated for elevation of INR or serum bilirubin as evidence of hepatic dysfunction.

Results

157/205 (77%) completed acetaminophen subjects had no ALT elevation or transient elevations that resolved by day 16. Of the 48 subjects who had ALT elevations at study day 16, 47 continued on acetaminophen and had resolution by study day 40. One acetaminophen subject did not have resolution by study day 40, and the course of aminotransferase elevation suggests an alternative cause. One placebo subject had an ALT elevation at day 16 that resolved by day 22. The highest observed ALT among all acetaminophen subjects was 191 IU/L. The mean ALT at day 16 was 4.4 IU/L higher for the acetaminophen than for the placebo group. No subject developed liver dysfunction.

Conclusions

A minority of subjects treated with 4 g/day of acetaminophen for 16 days will have low-grade aminotransferase elevations that are not accompanied by liver dysfunction and resolve if administration is continued.

Trials registration

Clintrials.gov NCT00743093 registered August 26, 2008

[Paracetamol. Efficacious and safe for all ages]

Paracetamol has become a focus of attention as being unsafe due to hepatic toxicity and market withdrawal or prescription status is presently under discussion in Germany. This drug is, however, effective and safe if notes of caution are applied. In Germany 38 fatal cases of analgesic poisoning were observed in 2010, only 4 of which were due to paracetamol and 16 were caused by diclofenac and ibuprofen. Alternative pain medications are obviously much less safe, in particular given the additional risk of sometimes fatal gastrointestinal bleeding and cardiovascular side effects. This review extensively analyzes the safety record of paracetamol and applies these findings to the treatment of elderly people. Even very elderly patients may be safely treated with this compound, although a dose limit of 3 g/day should be instituted. This renewed discussion was triggered by the uncontrolled availability of paracetamol in the USA but observations from this country should not be generalized and applied to the German situation and objective reasoning should be re-installed.

The effect of aging on acetaminophen pharmacokinetics, toxicity and Nrf2 in Fischer 344 rats

We investigated the effect of aging on hepatic pharmacokinetics and the degree of hepatotoxicity following a toxic dose of acetaminophen. Young and old male Fischer 344 rats were treated with 800 mg/kg acetaminophen (young n = 8, old n = 5) or saline (young n = 9, old n = 9). Serum measurements showed old rats treated with acetaminophen had significantly lower serum alanine aminotransferase and higher acetaminophen and acetaminophen glucuronide levels and creatinine, compared with acetaminophen treated young rats (p < .05). Immunoblotting and activity assays showed old saline-treated rats had twofold lower cytochrome P450 2E1 activity and threefold higher NAD(P)H quinone oxireductase 1 protein expression and activity than young saline-treated rats (p < .05), although Nrf2, glutathione cysteine ligase-modulatory subunit, glutathione cysteine ligase-catalytic subunit, and cytochrome P450 2E1 protein expressions were unchanged. Primary hepatocytes isolated from young rats treated with 10 mM acetaminophen had lower survival than those from old rats (52.4% ± 5.8%, young; 83.6% ± 1.7%, old, p < .05). The pharmacokinetic changes described may decrease susceptibility to acetaminophen-induced hepatotoxicity but may increase risk of nephrotoxicity in old age.

The modern pharmacology of paracetamol: therapeutic actions, mechanism of action, metabolism, toxicity and recent pharmacological findings

Paracetamol is used worldwide for its analgesic and antipyretic actions. It has a spectrum of action similar to that of NSAIDs and resembles particularly the COX-2 selective inhibitors. Paracetamol is, on average, a weaker analgesic than NSAIDs or COX-2 selective inhibitors but is often preferred because of its better tolerance. Despite the similarities to NSAIDs, the mode of action of paracetamol has been uncertain, but it is now generally accepted that it inhibits COX-1 and COX-2 through metabolism by the peroxidase function of these isoenzymes. This results in inhibition of phenoxyl radical formation from a critical tyrosine residue essential for the cyclooxygenase activity of COX-1 and COX-2 and prostaglandin (PG) synthesis. Paracetamol shows selectivity for inhibition of the synthesis of PGs and related factors when low levels of arachidonic acid and peroxides are available but conversely, it has little activity at substantial levels of arachidonic acid and peroxides. The result is that paracetamol does not suppress the severe inflammation of rheumatoid arthritis and acute gout but does inhibit the lesser inflammation resulting from extraction of teeth and is also active in a variety of inflammatory tests in experimental animals. Paracetamol often appears to have COX-2 selectivity. The apparent COX-2 selectivity of action of paracetamol is shown by its poor anti-platelet activity and good gastrointestinal tolerance. Unlike both non-selective NSAIDs and selective COX-2 inhibitors, paracetamol inhibits other peroxidase enzymes including myeloperoxidase. Inhibition of myeloperoxidase involves paracetamol oxidation and concomitant decreased formation of halogenating oxidants (e.g. hypochlorous acid, hypobromous acid) that may be associated with multiple inflammatory pathologies including atherosclerosis and rheumatic diseases. Paracetamol may, therefore, slow the development of these diseases. Paracetamol, NSAIDs and selective COX-2 inhibitors all have central and peripheral effects. As is the case with the NSAIDs, including the selective COX-2 inhibitors, the analgesic effects of paracetamol are reduced by inhibitors of many endogenous neurotransmitter systems including serotonergic, opioid and cannabinoid systems. There is considerable debate about the hepatotoxicity of therapeutic doses of paracetamol. Much of the toxicity may result from overuse of combinations of paracetamol with opioids which are widely used, particularly in USA.

Adverse effects of analgesics commonly used by older adults with osteoarthritis: focus on non-opioid and opioid analgesics

BACKGROUND

Osteoarthritis (OA) is the most common cause of disability in older adults, and although analgesic use can be helpful, it can also result in adverse drug events.

OBJECTIVE

To review the recent literature to describe potential adverse drug events associated with analgesics commonly used by older adults with OA.

METHODS

To identify articles for this review, a systematic search of the English-language literature from January 2001 to June 2012 was conducted using PubMed, MEDLINE, EBSCO, and the Cochrane Database of Systematic Reviews for publications related to the medical management of OA. Search terms used were "analgesics," "acetaminophen," "nonsteroidal anti-inflammatory drugs" (NSAIDs), "opioids," "pharmacokinetics," "pharmacodynamics," and "adverse drug events." The search was restricted to those articles that concerned humans aged ≥65 years. A manual search of the reference lists from identified articles and the authors' article files, book chapters, and recent reviews was conducted to identify additional articles. From these, the authors identified those studies that examined analgesic use in older adults.

RESULTS

There are limited data to suggest that non-frail elders are more likely than their younger counterparts to develop acetaminophen-induced hepatotoxicity. However, decreased hepatic phase II metabolism in frail elders may result in increased risk of hepatotoxicity. It is now well established that older adults are at higher risk of NSAID-induced gastrointestinal toxicity and renal insufficiency. Insofar as opioids, the data that suggest an increased risk of falls, fractures, or delirium need to be tempered by the potential risk of inadequately treating severe chronic OA-related pain.

CONCLUSIONS

Acetaminophen is the mainstay frontline analgesic for treating OA-related pain in older adults. NSAIDs should be limited to short-term use only, and for moderate to severe OA-related pain, opioids may be preferable in individuals without substance abuse or dependence issues.

High-risk prescribing and incidence of frailty among older community-dwelling men

Evidence about the association between treatment with high-risk medicines and frailty in older individuals is limited. We investigated the relationship between high-risk prescribing and frailty at baseline, as well as 2-year incident frailty, in 1,662 men ≥70 years of age. High-risk prescribing was defined as polypharmacy (≥5 medicines), hyperpolypharmacy (≥10 medicines), and by the Drug Burden Index (DBI), a dose-normalized measure of anticholinergic and sedative medicines. At baseline, frail participants had adjusted odds ratios (ORs) of 2.55 (95% confidence interval, CI: 1.69-3.84) for polypharmacy, 5.80 (95% CI: 2.90-11.61) for hyperpolypharmacy, and 2.33 (95% CI: 1.58-3.45) for DBI exposure, as compared with robust participants. Of the 1,242 men who were robust at baseline, 6.2% developed frailty over two years. Adjusted ORs of incident frailty were 2.45 (95% CI: 1.42-4.23) for polypharmacy, 2.50 (95% CI: 0.76-8.26) for hyperpolypharmacy, and 2.14 (95% CI: 1.25-3.64) for DBI exposure. High-risk prescribing may contribute to frailty in community-dwelling older men.

Drug metabolism in older people--a key consideration in achieving optimal outcomes with medicines

Hepatic clearance plays a key role in determining the systemic exposure of drugs and metabolites, which in turn has a major effect on variability in the beneficial and adverse effects of medicines. Aging results in a number of significant changes in the human liver including reductions in liver blood flow, size, drug-metabolizing enzyme content, and pseudocapillarization. Drug metabolism is also influenced by comorbid disease, frailty, concomitant medicines, and (epi)genetics. These changes have the potential to alter the hepatic clearance of drugs but need to be interpreted in the context of the pharmacokinetic (and pharmacodynamic) characteristics of the drug of interest. There is growing evidence that the age-related changes in the liver not only result in a decrease in the hepatic clearance of unbound drug but also influence variability in response to medicines in older people.

Age-related changes in the hepatic pharmacology and toxicology of paracetamol

Optimal pharmacotherapy is determined when the pharmacokinetics and pharmacodynamics of the drug are understood. However, the age-related changes in pharmacokinetics and pharmacodynamics, as well as the increased interindividual variation mean optimal dose selection are a challenge for prescribing in older adults. Poor understanding of how hepatic clearance and toxicity are different with age results in suboptimal dose selection, poor efficacy, and/or increased toxicity. Of particular concern is the analgesic paracetamol which has been in use for more than 50 years and is consumed by a large proportion of older adults. Paracetamol is considered to be a relatively safe drug; however, caution must be taken because of its potential for toxicity. Paracetamol-induced liver injury from accidental overdose accounts for up to 55% of cases in older adults. Better understanding of how age affects the hepatic clearance and toxicity of drugs will contribute to evidence-based prescribing for older people, leading to fewer adverse drug reactions without loss of benefit.

Clinical pharmacology of analgesic medicines in older people: impact of frailty and cognitive impairment

Pain is highly prevalent in frail older people who often have multiple co-morbidities and multiple medicines. Rational prescribing of analgesics in frail older people is complex due to heterogeneity in drug disposition, comorbid medical conditions, polypharmacy and variability in analgesic response in this population. A critical issue in managing older people with pain is the need for judicious choice of analgesics based on a comprehensive medical and medication history. Care is needed in the selection of analgesic medicine to avoid drug-drug or drug-disease interactions. People living with dementia and cognitive impairment have suboptimal pain relief which in part may be related to altered pharmacodynamics of analgesics and challenges in the systematic assessment of pain intensity in this patient group. In the absence of rigorously controlled trials in frail older people and those with cognitive impairment a pharmacologically-guided approach can be used to optimize pain management which requires a systematic understanding of the pharmacokinetics and pharmacodynamics of analgesics in frail older people with or without changes in cognition.

Age-related pseudocapillarization of the liver sinusoidal endothelium impairs the hepatic clearance of acetaminophen in rats

We investigated the effect of age-related pseudocapillarization of the liver sinusoidal endothelium on the hepatic disposition of acetaminophen. The multiple indicator dilution technique assessed the hepatic disposition of tracer (14)C-acetaminophen and reference markers in isolated perfused livers of young (n = 11) and old (n = 12) rats. Electron microscopy confirmed defenestration of the sinusoidal endothelium in old rats compared with young rats. Acetaminophen recovery following a single pass through the liver was significantly increased in old rats (0.64 ± 0.04, old; 0.59 ± 0.05, young; p < .05). In old age, there was significant reduction of the intercompartmental rate constant k(1) (0.34 ± 0.10 s(-1), old; 0.61 ± 0.38 s(-1), young; p < .05) and the permeability-surface area product for the transfer of acetaminophen across the sinusoidal endothelium (0.034 ± 0.006 mL/s/g, old; 0.048 ± 0.014 mL/s/g, young; p < .005). There was no difference in k(3), the measure of sequestration of acetaminophen that reflects enzyme activity. Age-related pseudocapillarization of the liver sinusoid resulted in increased acetaminophen recovery and decreased transfer of acetaminophen into the liver.