A population-based case-crossover study of polyethylene glycol use and acute renal failure risk in the elderly

PEGylation and Cell-Penetrating Peptides: Glimpse into the Past and Prospects in the Future

Several drug molecules have shown low bioavailability and pharmacokinetic profile due to metabolism by enzymes, excretion by the renal system, or due to other physiochemical properties of drug molecules. These problems have resulted in the loss of efficacy and the gain of side effects associated with drug molecules. PEGylation is one of the strategies to overcome these pharmacokinetic issues and has been successful in the clinic. Cell-penetrating Peptides (CPPs) help to deliver molecules across biological membranes and could be used to deliver cargo selectively to the intracellular site or to the drug target. Hence CPPs could be used to improve the efficacy and selectivity of the drug. However, due to the peptidic nature of CPPs, they have a low pharmacokinetic profile. Using PEGylation and CPPs together as a component of a drug delivery system, the and efficacy of drug molecules could be improved. The other important pharmacokinetic properties such as short half-life, solubility, stability, absorption, metabolism, and elimination could be also improved. Here in this review, we summarized PEGylated CPPs or PEGylation based formulations for CPPs used in a drug delivery system for several biomedical applications until August 2019.

Colonoscopy in the very elderly

INTRODUCTION

Colonoscopy is the gold standard test for investigating lower gastrointestinal symptoms and is an important therapeutic tool for colonic polypectomy. This paper is aimed at the general physician and examines the role of colonoscopy in very elderly patients by exploring the particular risks in this population, the yield of colonoscopy and potential alternative investigations.

SOURCES OF DATA

Original research and review articles were identified through selective PubMed searches. Guidelines were identified through interrogation of national and international society websites in addition to PubMed searches.

AREAS OF AGREEMENT

Advanced age alone is not a reason to avoid investigation. The decision to perform colonoscopy in this population must take into account indication and yield, risks of the procedure and bowel preparation, physical fitness of the patient, potential alternative and the ability to consent. As a general rule, the principle of 'first doing no harm' should be applied and requires balancing of the risks of the procedure and preparation with the benefits of doing the test.

AREAS OF CONTROVERSY

There is no defined upper age limit at which colonoscopy is contraindicated, however; the National Health Service Bowel Cancer Screening Programme stops inviting patients for screening and surveillance colonoscopy at age 75.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

The concepts of 'first do no harm' and shared decision-making are not new but are increasingly important, particularly in this patient group. It is crucial to provide patients with information about risks, benefits and alternative investigations to empower their decision-making.

Risk factors for and the prevention of acute kidney injury after abdominal surgery

Postoperative acute kidney injury in patients undergoing abdominal surgery is not rare and often results in bad outcomes for patients. The incidence of postoperative acute kidney injury is hard to evaluate reliably due to its non-unified definitions in different studies. Risk factors for acute kidney injury specific to abdominal surgery include preoperative renal insufficiency, intraabdominal hypertension, blood transfusion, bowel preparation, perioperative dehydration, contrast agent and nephrotoxic drug use. Among these, preoperative renal insufficiency is the strongest predictor of acute kidney injury. The peri-operative management of high-risk patients should include meticulous selection of fluid solutions. Balanced crystalloid solutions and albumin are generally thought to be relatively safe, while the safety of hydroxyethyl starch solutions has been controversial. The purpose of the present review is to discuss the current knowledge regarding postoperative acute kidney injury in abdominal surgical settings to help surgeons make better decisions concerning the peri-operative management.

Does 2 L Polyethylene Glycol Plus Ascorbic Acid Increase the Risk of Renal Impairment Compared to 4 L Polyethylene Glycol?

BACKGROUND

The use of polyethylene glycol (PEG)-based solutions is the gold standard for bowel preparation. However, PEG use might be associated with the risk of acute kidney injury.

AIMS

We aimed to compare the safety of 2 L PEG plus ascorbic acid (AA) versus 4 L PEG.

METHODS

Health examinees that underwent colonoscopy and blood tests on the same day at our center were included in this retrospective study. All subjects were prescribed either 2 L PEG plus AA or 4 L PEG for the bowel preparation prior to the colonoscopy. The incidences of electrolyte imbalance and renal impairment after colonic preparation were investigated. Renal impairment was determined if the subject's estimated glomerular filtration rate was measured less than 60 mL/min/1.73 m².

RESULTS

Of the 29,789 cases, 14,790 received 2 L PEG plus AA (group A) and 14,999 received 4 L PEG (group B) for colonic preparation. Renal impairment occurred more commonly in group A (n = 467, 3.2 %) than in group B (n = 189, 1.3 %). Electrolyte changes such as hypernatremia and hyperkalemia were more common in group A than group B, whereas hyponatremia, hypokalemia, and hypophosphatemia were more common in group B than group A. Old age, male sex, and the use of 2 L PEG plus AA were independent risk factors for renal impairment.

CONCLUSIONS

The evidence strongly suggests that acute kidney injury is more likely to occur when 2 L PEG plus AA is used for the bowel preparation than when 4 L PEG is used.

CLINICAL TRIAL REGISTRATION NUMBER

KCT0001703.

Clinical and Economic Burden of Visual Impairment in an Aging Society of South Korea

Whereas the incidence of visual impairment and blindness (VI&B) is decreasing, the total number of VI&B is increasing due to the growth of elderly population. To compare the clinical and economic outcomes of patients with and without VI&B (ie, cases and controls) in Korea, a case–control study was performed using the Health Insurance Review and Assessment Service–National Patients Sample data. Cases had higher prevalence for all of the Charlson Comorbidity Index components, depression, fracture, and injury as well as eye diseases compared to age- and sex-matched controls. In regression after adjustment of concomitant diseases, cases had 2.7 times (95% confidence interval = 2.3-3.2) higher medical expenditure than controls. The results of this study confirm that patients with VI&B have significantly higher direct medical expenditures and concomitant diseases than those without VI&B and highlight the need for a public health strategy to reduce potentially avoidable costs attributed to VI&B.

Multi-indication carbamazepine and the risk of severe cutaneous adverse drug reactions in Korean elderly patients: a Korean health insurance data-based study

Objective

To evaluate the risk of severe cutaneous adverse drug reactions (SCAR) after exposure to multi-indication antiepileptic drugs for in Korean elderly patients.

Methods

We used a nationwide database from the Korean Health Insurance Review and Assessment Service claims constructed for the monitoring of drug utilization among the entire Korean elderly population from January 2005 to June 2006. We identified cases of SCARs among inpatients aged ≥65 years and those newly diagnosed with erythema multiforme according to the International Classification of Diseases, 10th revision code (L51). Each case was matched to four controls for gender, age, and the first hospitalization date as the index date. The use of carbamazepine, gabapentin, lamotrigine, topiramate, phenobarbital, phenytoin, and valproate during a 60-day period before the index date was compared. A conditional logistic regression analysis was performed to calculate the odds ratios (OR) and 95% confidence intervals (CI) of SCARs for antiepileptic drug.

Results

We identified 286 cases of SCAR and 1,144 matched controls. Among the 25 patients who were prescribed antiepileptic drugs within 60 days of the index date. There were 11 cases (3.8%) of severe ocular manifestations, and most elderly patients were first-time or short-term users of antiepileptic drugs. Among the 10 cases of carbamazepine use, only 2 cases were prescribed carbamazepine for seizure. All antiepileptic drugs were associated with an increased SCAR risk (adjusted OR = 3.42, 95% CI: 1.75–6.63). The SCAR risk was highest in patients treated with carbamazepine (adjusted OR = 10.39, 95% CI: 2.64–40.86, for multi-indication; adjusted OR = 6.84, 95% CI: 1.55–30.10, for neuropathic pain).

Conclusion

Carbamazepine use was associated with a nearly 10-fold increase in severe cutaneous drug reactions in Korean elderly patients. This association was consistently high with SCAR patients who received carbamazepine for neuropathic pain.

Basics and recent advances in peptide and protein drug delivery

While the peptide and protein therapeutic market has developed significantly in the past decades, delivery has limited their use. Although oral delivery is preferred, most are currently delivered intravenously or subcutaneously due to degradation and limited absorption in the gastrointestinal tract. Therefore, absorption enhancers, enzyme inhibitors, carrier systems and stability enhancers are being studied to facilitate oral peptide delivery. Additionally, transdermal peptide delivery avoids the issues of the gastrointestinal tract, but also faces absorption limitations. Due to proteases, opsonization and agglutination, free peptides are not systemically stable without modifications. This review discusses oral and transdermal peptide drug delivery, focusing on barriers and solutions to absorption and stability issues. Methods to increase systemic stability and site-specific delivery are also discussed.

Consensus guidelines for the use of bowel preparation prior to colonic diagnostic procedures: colonoscopy and small bowel video capsule endoscopy

BACKGROUND

Adequate bowel preparation prior to colonic diagnostic procedures is essential to ensure adequate visualisation.

SCOPE

This consensus aims to provide guidance as to the appropriate use of bowel preparation for a range of defined clinical circumstances. A consensus group from across Europe was convened and met to discuss appropriate bowel preparation. The use of polyethylene glycol (PEG), sodium picosulphate and sodium phosphate (NaP), together with other agents, prokinetics and simethicone, in colonoscopy and small bowel video capsule endoscopy were considered. A systematic review of the literature was carried out and additional unpublished data was obtained from the members of the consensus group where required. Recommendations were graded according to the level of evidence.

FINDINGS

PEG-based regimens are recommended first line for both procedures, since their use is supported by good efficacy and safety data. Sodium-picosulphate-based regimens are recommended second line as their cleansing efficacy appears less than PEG-based regimens. NaP is not recommended for bowel cleansing due to the potential for renal damage and other adverse events. However, the use of NaP is acceptable in patients in whom PEG or sodium picosulphate is ineffective or not tolerated. NaP should not be used in patients with chronic kidney disease, pre-existing electrolyte disturbances, congestive heart failure, cirrhosis or a history of hypertension. The timing of the dose, dietary restrictions, use in special patient groups and recording of the quality of bowel preparation are also considered for patients undergoing colonoscopy. During the development of the guidelines the European Society of Gastrointestinal Endoscopy (ESGE) issued guidance on bowel preparation for colonoscopy. The ESGE guidelines and these consensus guidelines share many recommendations; differences between the guidelines are reviewed.

CONCLUSION

The use of bowel preparation should be tailored to the individual patient and their specific clinical circumstances.