Drug therapy: drug disposition in old age

Central Nervous System Medications: Pharmacokinetic and Pharmacodynamic Considerations for Older Adults

Most drugs have not been evaluated in the older population. Recognizing physiological alterations associated with changes in drug disposition and with the ultimate effect, especially in central nervous system-acting drugs, is fundamental. While considering pharmacokinetics, it should be noted that the absorption of most drugs from the gastrointestinal tract does not change in advanced age. There are only few data about the effect of age on the transdermal absorption of medications such as fentanyl. Absorption from an intramuscular injection may be similar in older adults as in younger patients. The distribution of lipophilic drugs (such as diazepam) is increased owing to a relative increase in the percentage of body fat, causing drug accumulation and prolonged drug elimination following cessation. Phase I drug biotransformation is variably decreased in aging, impacting elimination, and hepatic drug clearance has been shown to decrease in older individuals by 10-40% for most drugs studied. Lower doses of phenothiazines, butyrophenones, atypical antipsychotics, antidepressants (citalopram, mirtazapine, and tricyclic antidepressants), and benzodiazepines (such as diazepam) achieve the same extent of exposure. For renally cleared drugs with no prior metabolism (such as gabapentin), the glomerular filtration rate appropriately estimates drug clearance. Important pharmacodynamic changes in older adults include an increased sedative effect of benzodiazepines at a given drug exposure, and a higher sensitivity to mu opiate receptor agonists and to opioid adverse effects. Artificial intelligence, physiologically based pharmacokinetic modeling and simulation, and concentration-effect modeling enabling a differentiation between the pharmacokinetic and the pharmacodynamic effects of aging might help to close some of the gaps in knowledge.

Efficacy and Safety of Sufentanil Infusion for Postoperative Analgesia in Cancer Surgery: A Retrospective Cohort Study

Background Opioids have long been the cornerstone of drugs used for perioperative analgesia. Sufentanil has an advantageous pharmacological profile for its use in continuous intravenous (IV) infusion, yet remains poorly described. Our institution has implemented analgesia protocols with IV sufentanil infusions for cancer surgery with appropriate monitoring. The aim of this study was to evaluate the efficacy and safety of IV sufentanil infusion. Methods A single-center retrospective cohort study was conducted through the analysis of patients' records and the acute pain service database. Inclusion criteria were adult patients admitted for elective cancer surgery and with postoperative IV sufentanil infusion during one year period. Descriptive and inferential statistical analysis was performed by using Software SPSS Statistics (IBM Corp., Armonk USA): Kruskal-Wallis, Mann-Whitney, Chi-square and Fisher tests; Bonferroni chi-square residual analysis, binary logistic regression; p<0.05. Results The study population of 304 patients had a median age of 66 years (22-91) and 229 (75.3%) were men. 38 (12.5%) were chronic opioid users. Head and neck/otorhinolaryngology (ORL) surgery was performed in 155 (51.0%) and abdominopelvic surgery in 123 (40.5%). The median days of IV sufentanil infusion were 2 (1-13). At rest and with movement, analgesia was considered good, i.e., over 90% of patients with visual analogue scale (VAS) pain score ≤ 3. We found that patients submitted to musculoskeletal surgery had higher VAS pain scores; this group also presented older patients with higher American Society of Anesthesiologists (ASA) physical status classification and more chronic opioid users (p<0.05). 144 patients (47.4%) had at least one adverse effect related to IV sufentanil infusion, notably transient and not requiring any specific treatment. These patients were older and had longer infusion periods (p<0.05). 237 (98.3%) of the adverse effects occurred during the first 3 days and the most common were: sedation (n=104, 42.8%), hypotension (n=32, 13.2%), hypoxemia (n=31, 12.8%) and nausea/vomiting (n=25, 10.3%). The reported incidence of respiratory depression was 2.9% (n=9), with three patients (1%) requiring advanced treatment. Conclusion Multimodal analgesic protocols with IV sufentanil infusions provided good postoperative analgesia for head and neck/ORL and abdominopelvic cancer surgeries. The adverse effects associated with the IV sufentanil infusions were mild and mainly managed with opioid dose reductions. Our study showed that this approach can be a safe option for postoperative multimodal analgesia in cancer surgery with appropriate monitoring in high-dependency units.

Valproate-related neutropenia and lithium-related leukocytosis in patients treated with clozapine: a retrospective cohort study

BACKGROUND

Neutropenia is a noteworthy side effect of clozapine, which might warrant this drugs' discontinuance for safety. Studies have revealed that the risk of neutropenia increases with concurrent administration of valproate, but the evidence was limited. Conversely, lithium may have an ameliorating effect on clozapine-induced neutropenia. This study explored the effects of valproate and lithium on white blood cell counts in patients treated with clozapine.

METHODS

We retrospectively investigated the electronic medical records from one tertiary psychiatric hospital in Taiwan and enrolled patients discharged between January 1, 2006, and December 31, 2017, with clozapine prescriptions. We scrutinized their demographic data, medications, and hematological results at discharge and during follow-up outpatient clinic visits over the subsequent 3 years. Patients were classified into four groups: clozapine only (CLO), clozapine and valproate (CLO + VAL), clozapine and lithium (CLO + Li), and clozapine, valproate, and lithium (CLO + VAL + Li). We also identified hematological events (neutropenia or leukocytosis) of these patients during outpatient follow-ups.

RESULTS

Of the included 1084 patients, 55(5.1%) developed neutropenia. Concurrent valproate use (odds ratio [OR] = 3.49) and older age (p = .007) were identified as risk factors. Moreover, 453 (41.79%) patients developed leukocytosis. Younger age; male sex; and concurrent use of lithium (OR = 3.39, p < .001), clozapine daily dosage, and benzodiazepines were the risk factors for leukocytosis.

CONCLUSION

Concurrent valproate use and older age are associated with the development of neutropenia in patients treated with clozapine. Concurrent lithium usage, younger age, male sex, and concurrent benzodiazepine use might be related to leukocytosis.

Measurement of Postoperative Quality of Pain in Abdominoplasty Patients-An Outcome Oriented Prospective Study

(1) Background: Postoperative pain is a frequently underestimated complication significantly influencing surgical outcome and patient satisfaction. While abdominoplasty is one of the most commonly performed plastic surgery procedures, studies investigating postoperative pain are limited in current literature. (2) Methods: In this prospective study, 55 subjects who underwent horizontal abdominoplasty were included. Pain assessment was performed by using the standardized questionnaire of the Benchmark Quality Assurance in Postoperative Pain Management (QUIPS). Surgical, process and outcome parameters were then used for subgroup analysis. (3) Results: We found a significantly decreased minimal pain level in patients with high resection weight compared to the low resection weight group (p = 0.01 *). Additionally, Spearman correlation shows significant negative correlation between resection weight and the parameter "Minimal pain since surgery" (rs = -0.332; p = 0.013). Furthermore, average mood is impaired in the low weight resection group, indicating a statistical tendency (p = 0.06 and a Χ² = 3.56). We found statistically significant higher maximum reported pain scores (rs = 0.271; p = 0.045) in elderly patients. Patients with shorter surgery showed a statistically significant (Χ² = 4.61, p = 0.03) increased claim for painkillers. Moreover, "mood impairment after surgery" shows a dramatic trend to be enhanced in the group with shorter OP duration (Χ² = 3.56, p = 0.06). (4) Conclusions: While QUIPS has proven to be a useful tool for the evaluation of postoperative pain therapy after abdominoplasty, only continuous re-evaluation of pain therapy is a prerequisite for constant improvement of postoperative pain management and may be the first approach to develop a procedure-specific pain guideline for abdominoplasty. Despite a high satisfaction score, we detected a subpopulation with inadequate pain management in elderly patients, patients with low resection weight and a short duration of surgery.

Medical and surgical treatment of epilepsy in older adults: A national survey

OBJECTIVE

There are no clinical guidelines dedicated to the treatment of epilepsy in older adults. We investigated physician opinion and practice regarding the treatment of people with epilepsy aged 65 years or older. We also sought to study how our opinion and practice varied between geriatricians, general neurologists, and epilepsy neurologists (i.e., epileptologists).

METHODS

We initially piloted our survey to measure test-retest reliability. Once finalized, we disseminated the survey via two rounds of facsimiles, and then conventional mail, to eligible individuals listed in a national directory of Canadian physicians. We used descriptive statistics such as stacked bar charts and tables to illustrate our findings.

RESULTS

One hundred forty-four physicians (104 general neurologists, 25 geriatricians, and 15 epileptologists) answered our survey in its entirety (overall response rate of 13.2%). Levetiracetam and lamotrigine were the preferred antiseizure medications (ASMs) to treat older adults with epilepsy. Two thirds of epileptologists and almost half of general neurologists would consider prescribing lacosamide in >50% of people aged >65 years; only one geriatrician was of the same opinion. More than 40% of general neurologists and geriatricians erroneously believed that none of the ASMs mentioned in our survey was previously studied in randomized controlled trials specific to the treatment of epilepsy in older adults. Epileptologists were more likely as compared to general neurologists and geriatricians to recommend epilepsy surgery (e.g., 66.6% vs. 22.9%-37.5% among older adults).

SIGNIFICANCE

Therapeutic decisions for older adults with epilepsy are heterogeneous between physician groups and sometimes misalign with available clinical evidence. Our surveyed physicians differed in their approach to ASM choice as well as perception of surgery in older adults with epilepsy. These findings likely reflect the lack of clinical guidelines dedicated to this population and the deficient implementation of best practices.

Factors affecting sufentanil consumption for intravenous controlled analgesia after hepatectomy: retrospective analysis

Background

Pain control after hepatectomy is usually achieved by opioids. There are significant individual differences in the amount of opioids used after hepatectomy, and the metabolism of opioids is liver-dependent. The purpose of our study was to explore the possible risk factors for opioid consumption during the first 48 h after surgery.

Methods

In a retrospective study design involving 562 patients undergoing open or laparoscopic hepatectomy, all patients were treated with intravenous patient-controlled analgesia (IV-PCA) along with continuous and bolus doses of sufentanil for a duration of 48 h after surgery during the time period of August 2015 and February 2019. The primary endpoint was high sufentanil consumption 48 h after hepatectomy, and patients were divided into two groups: those with or without a high PCA sufentanil dosage depending on the third quartile (Q3). The secondary endpoint was the effect of a high PCA sufentanil dosage on various possible clinical risk factors. The relevant parameters were collected, and correlation and multivariate regression analyses were performed.

Results

The median operation time was 185 min (range, 115–250 min), and the median consumption of sufentanil 48 h after the operation was 91 μg (IQR, 64.00, 133.00). Factors related to the consumption of sufentanil at 48 h after hepatectomy included age, operation time, blood loss, intraoperative infusion (red blood cells and fresh-frozen plasma), pain during movement after surgery (day 1 and day 2), preoperative albumin, and postoperative blood urea nitrogen. Age (≤ 60 and > 60 years), extent of resection (minor hepatic resection and major hepatic resection), surgical approach (laparoscope and open) and operation time (min) were independent risk factors for sufentanil consumption at 48 h postoperatively.

Conclusion

Age younger than 60 years, major hepatic resection, an open approach and a longer operation are factors more likely to cause patients to require higher doses of sufentanil after hepatectomy, and the early identification of such patients can increase the efficacy of perioperative pain management.

Influence of CYP2C19 Polymorphisms on the Pharmacokinetics of Omeprazole in Elderly Subjects

Omeprazole blocks the gastric H⁺ /K⁺  adenosine triphosphatase, thus inhibiting gastric acid secretion, and is metabolized by cytochrome P450 (CYP) 2C19. Due to the physiological changes in the elderly, there are different pharmacokinetic consequences compared to young people. The aim of this study was to evaluate the pharmacokinetic profiles of omeprazole in 15 elderly participants according to the CYP2C19 genotype. The concentration-time profiles of omeprazole and its metabolites, 5-hydroxy (5-OH) omeprazole and omeprazole sulfone, were similar between the CYP2C19 extensive metabolizer (EM) and intermediate metabolizer groups. In contrast, when comparing the EM group and CYP2C19 poor metabolizer (PM) group, the EM/PM geometric mean ratio (95% confidence interval) of area under the plasma concentration-time curve from time of dosing to the last measurable concentration was 0.52 (0.27-1.01) and that of the IM group was 0.71 (0.32-1.59), indicating that the exposure of omeprazole in the PM group was increased. The exposure of 5-OH omeprazole was significantly decreased in the PM group when compared to the EM group, with an EM/PM geometric mean ratio (95% confidence interval) of 2.20 (1.50-3.22). In conclusion, the tendency of drug exposure according to the CYP2C19 genotype in the elderly and young adults was similar in that the exposure level was highest in the PM group. However, when compared to young adults, the difference between the genotype groups was smaller in the elderly.

Pharmacokinetics and Safety of Chiglitazar, a Peroxisome Proliferator-Activated Receptor Pan-Agonist, in Patients < 65 and ≥ 65 Years With Type 2 Diabetes

The effect of age on the pharmacokinetics and safety of chiglitazar was evaluated in patients < 65 and ≥ 65 years with type 2 diabetes mellitus (T2DM). A total of 20 T2DM patients (<65 vs ≥65 years 1:1) completed the study. Patients received multiple doses of 48 mg chiglitazar once daily for 7 days consecutively. After the first dosing, chiglitazar maximum plasma concentration (C_max ) and area under the plasma concentration-time curve (AUC) in patients ≥ 65 years were similar to those observed in patients < 65 years, with the geometric mean ratio (GMR) for C_max and AUC being 97.22% and 96.83%, respectively. No significant difference was observed in C_max (GMR, 97.23%) in the steady state. Compared with the patients < 65 years, a slight increase (8%-13%) of AUC was observed in the patients ≥ 65 years after multiple doses. Chiglitazar was generally well tolerated following multiple doses in both age groups. In conclusion, there were no significant clinical influences on the pharmacokinetic properties and safety profiles of chiglitazar between patients with T2DM < 65 and ≥ 65 years, indicating that in the future it is not required to adjust the dosing regimen by age for T2DM patients ≥ 65 years.

Slow Accumulation and Elimination of Diazepam and Its Active Metabolite With Extended Treatment in the Elderly

Age-related changes in disposition of diazepam and its principal active metabolite, desmethyldiazepam (DMDZ), during and after extended dosage with diazepam were studied in healthy volunteers. Eight elderly subjects (ages 61-78 years) and 7 young subjects (21-33 years) received 2.5 mg of diazepam twice daily for 15 days. Predose (trough) concentrations of diazepam and DMDZ were measured during the 15 days of dosing, and in the postdosage washout period. Kinetic properties were determined by nonlinear regression using a sequential drug-to-metabolite pharmacokinetic model. Steady-state plasma concentrations of diazepam and DMDZ were 30% to 35% higher in elderly subjects compared to young volunteers, and steady-state clearances correspondingly lower, though differences did not reach significance. Large and significant differences were found between young and elderly groups in mean half-life of diazepam (31 vs 86 hours; P < .005) and DMDZ (40 vs 80 hours; P < .02). Half-life values from the multiple-dose study were closely correlated with values from previous single-dose studies of diazepam (R² = 0.85) and DMDZ (R² = 0.94) in the same subjects. With extended dosing of diazepam in the elderly, slow accumulation and delayed washout of diazepam and DMDZ is probable. After discontinuation, withdrawal or rebound effects are reduced in likelihood, but delayed recovery from sedative effects is possible due to slow elimination of active compounds. Safe treatment of elderly patients with diazepam is supported by understanding of age-related changes in pharmacologic and pharmacokinetic properties.

Efficacy and acceptability of tianeptine in the elderly: a review of clinical trials

The acceptability and efficacy of tianeptine were evaluated in three open trials in a total of 549 elderly patients, 426 of whom were treated for 3 months and 188 for 1 year. The therapeutic effect was that expected from an effective antidepressant, with a marked response after treatment for one month. In the geriatric trial, where patients were primarily dysthymic, continuation of treatment after 6 months consolidated the improvement already observed. Tianeptine also had a favorable long-term effect in chronic refractory depression. Drop-outs due to side-effects were few (4.4%), despite the high risk population. All pre-treatment complaints improved on tianeptine. The high frequency of somatic complaints expressed before treatment confirmed the extent to which depression is somatised in the elderly. Concomitant physical disease present in 87% of patients did not restrict the use of tianeptine. The fact that tianeptine has a low incidence of anticholinergic effects and no affinity for either H1 or α1 receptors makes it a particularly easy drug to use in elderly subjects who are sensitive to the side-effects of psychotropic agents.

Computational models for predicting anticancer drug efficacy: A multi linear regression analysis based on molecular, cellular and clinical data of oral squamous cell carcinoma cohort

BACKGROUND AND OBJECTIVES

The computational prediction of drug responses based on the analysis of multiple clinical features of the tumor will be a novel strategy for accomplishing the long-term goal of precision medicine in oncology. The cancer patients will be benefitted if we computationally account all the tumor characteristics (data) for the selection of most effective and precise therapeutic drug. In this study, we developed and validated few computational models to predict anticancer drug efficacy based on molecular, cellular and clinical features of 31 oral squamous cell carcinoma (OSCC) cohort using computational methods.

METHODS

We developed drug efficacy prediction models using multiple tumor features by employing the statistical methods like multi linear regression (MLR), modified MLR-weighted least square (MLR-WLS) and enhanced MLR-WLS. All the three developed drug efficacy prediction models were then validated using the data of actual OSCC samples (train-test ratio 31: 31) and actual Vs hypothetical samples (train-test ratio 31: 30). The selected best statistical model i.e. enhanced MLR-WLS has then been cross-validated (CV) using 341 theoretical tumor data. Finally, the performances of the models were assessed by the level of learning confidence, significance, accuracy and error terms.

RESULTS

The train-test process for the real tumor samples of MLR-WLS method revealed the drug efficacy prediction enhancement and we observed that there was very less priming difference between actual and predicted. Furthermore, we found there was a less difference between actual apoptotic priming and predicted apoptotic priming for the tumors 6, 8, 21 and 30 whereas, for the remaining tumors there were no differences between predicted and actual priming data. The error terms (Actual Vs Predicted) also revealed the reliability of enhanced MLR-WLS model for drug efficacy prediction.

CONCLUSION

We developed effective computational prediction models using MLR analysis for anticancer drug efficacy which will be useful in the field of precision medicine to choose the choice of drug in a personalized manner. We observed that the enhanced MLR-WLS model was the best fit to predict anticancer drug efficacy which may have translational applications.

Efficacy and Safety of Deep Sedation in Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma

INTRODUCTION

Radiofrequency ablation (RFA) has been accepted as safe and effective for treating early-stage hepatocellular carcinoma (HCC). However, it often causes severe pain. Therefore, in this study, we performed RFA under deep sedation and investigated its efficacy and safety.

METHODS

We conducted a retrospective study including 511 HCC patients who received approximately 886 RFA treatments between December 2014 and November 2016 at our institution. Respiratory depression was defined as oxygen saturation of below 90%; and severe body movement was defined as movement caused by pain, which was managed by lowering the power of the generator. Factors associated with respiratory depression and severe body movement were examined via univariate and multivariate regression analyses.

RESULTS

Respiratory depression occurred in 15.3% of the patients and severe body movement in 26.5% of the patients. In the multivariate analysis, BMI (≥ 25 kg/m², odds ratio [OR] = 1.75, P = 0.035) and longer ablation (≥ 10 min, OR = 2.59, P = 0.002) were significant respiratory depression-related factors. Male sex (OR = 2.02, P = 0.005), Child-Pugh class A (odds ratio = 1.96, P = 0.018), and longer ablation (≥ 10 min, OR = 3.03, P < 0.001) were significant factors related to severe body movement.

CONCLUSION

Deep sedation for RFA can be performed safely and effectively. Higher BMI and longer ablation were risk factors for respiratory depression and male sex, Child-Pugh class A, and longer ablation were independent predictors of severe body movement during RFA under deep sedation.

Caring for the critically ill patients over 80: a narrative review

Background

There is currently no international recommendation for the admission or treatment of the critically ill older patients over 80 years of age in the intensive care unit (ICU), and there is no valid prognostic severity score that includes specific geriatric assessments.

Main body

In this review, we report recent literature focusing on older critically ill patients in order to help physicians in the multiple-step decision-making process. It is unclear under what conditions older patients may benefit from ICU admission. Consequently, there is a wide variation in triage practices, treatment intensity levels, end-of-life practices, discharge practices and frequency of geriatrician’s involvement among institutions and clinicians. In this review, we discuss important steps in caring for critically ill older patients, from the triage to long-term outcome, with a focus on specific conditions in the very old patients.

Conclusion

According to previous considerations, we provide an algorithm presented as a guide to aid in the decision-making process for the caring of the critically ill older patients.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0458-7) contains supplementary material, which is available to authorized users.

Lamotrigine pharmacokinetics following oral and stable-labeled intravenous administration in young and elderly adult epilepsy patients: Effect of age

OBJECTIVE

The objectives of this study were to investigate the effect of age on pharmacokinetic parameters of lamotrigine (LTG) and estimate parameter variability.

METHODS

Patients (>18 years old) who were already on a steady-state dose of LTG therapy with no interacting comedications were enrolled. Patients with significant cardiac disease, severe kidney dysfunction, or moderate-to-severe liver dysfunction were excluded. Fifty milligrams of a stable-labeled intravenous LTG formulation (SL-LTG) replaced 50 mg of a patient's normal daily oral LTG dose. Thirteen blood samples were collected in each person over 96 hours. SL-LTG and unlabeled LTG concentrations were measured simultaneously by gas chromatography-mass spectrometry. Concentration-time data were analyzed by nonlinear mixed-effects modeling (NONMEM version 7.3).

RESULTS

Twenty-eight patients representing 16 young (18-48 years old) and 12 elderly (63-87 years old) patients were included, yielding 382 unlabeled and 351 SL-LTG concentrations. A two-compartment model with first-order absorption and elimination adequately described the plasma concentration-time data. Bioavailability of oral LTG was approximately 74% and did not differ by age. LTG clearance was 27.2% lower in elderly than in young patients (1.80 L/h for a 70-kg patient).

SIGNIFICANCE

Although LTG bioavailability was not affected by age, LTG clearance was 27.2% lower in elderly versus young patients of comparable body weight, possibly indicating lower dosages being needed in this population.

Short-Term Outcomes following Hepatectomy in Elderly Patients with Hepatocellular Carcinoma: An Analysis of 10,805 Septuagenarians and 2,381 Octo- and Nonagenarians in Japan

BACKGROUND

As the population is aging, the indication for hepatocellular carcinoma (HCC) resection in patients aged over 80 years will increase. Japan is facing the most aging society worldwide. We examined the safety of hepatectomy in octogenarians and nonagenarians using large-scale data from the Diagnosis Procedure Combination database, a national administrative database in Japan.

METHOD

We conducted a survey to collect data for all inpatients from 2007 and 2012. We identified 27,094 patients who underwent hepatectomy for HCC. Patients' age was divided into the following five categories: ≤59, 60-69, 70-79, 80-84, and ≥85 years (n = 5,099, 8,809, 10,805, 2,011, and 370, respectively). The primary outcomes of hepatectomy were in-hospital death within 90 days and complications. Logistic regression analyses were performed to analyze the impact of age on the outcomes with the adjustment of other individual-level factors.

RESULTS

The mortality and morbidity rates were 2.6 and 23.4%, respectively. Compared with patients in their 70s, the mortality rate was significantly lower in patients aged ≤59 years (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.26-0.45; p < 0.01) and in those in their 60s (OR, 0.63; 95% CI, 0.53-0.74; p < 0.01). However, no significant difference was observed in patients aged 80-84 years (OR, 1.03; 95% CI, 0.78-1.385; p = 0.844) and those aged ≥85 years (OR, 0.95; 95% CI, 0.50-1.79; p = 0.870). Based on the multivariate logistic regression analysis, age ≥70 years, male gender, low hospital volume, and surgical procedure were identified as independent predictors of mortality.

CONCLUSIONS

The operative risk for hepatectomy gradually increases with age until patients are in their 70s, and it appears to reach a plateau among septuagenarian. Indeed, age over 70 years can also be a risk factor for HCC. By considering the aging risk, surgeons can attain good outcome after hepatectomy even in octo- and nonagenarian patients.

Population Pharmacokinetic Modeling of Tribendimidine Metabolites in Opisthorchis viverrini-Infected Adults

There is a pressing need for alternative treatments against the liver fluke Opisthorchis viverrini. Oral tribendimidine is a promising candidate, but its population pharmacokinetic properties are unknown. Two phase IIa trials were conducted in Laos in O. viverrini-infected adults receiving single oral doses of 25 to 600 mg tribendimidine administered as different formulations in each study (study 1 used 200-mg tablets, and study 2 used 50-mg tablets). Venous whole blood, plasma, and capillary dried blood spots were sampled frequently from 68 adults, and concentrations of the tribendimidine metabolites dADT (deacetylated amidantel) and adADT (acetylated dADT) were measured. Population pharmacokinetics were assessed by using nonlinear mixed-effects modeling. The relationship between drug exposure and cure (assessed at 21 days posttreatment) was evaluated by using univariable logistic regression. A six-transit compartment absorption model with a one-disposition compartment for each metabolite described the data well. Compared to the 50-mg formulation (study 2), the 200-mg formulation (study 1) had a 40.1% higher mean transit absorption time, a 113% higher dADT volume of distribution, and a 364% higher adADT volume of distribution. Each 10-year increase in age was associated with a 12.7% lower dADT clearance and a 21.2% lower adADT clearance. The highest cure rates (≥55%) were observed with doses of ≥100 mg. Higher dADT, but not adADT, peak concentrations and exposures were associated with cure (P = 0.004 and 0.003, respectively). For the first time, population pharmacokinetics of tribendimidine have been described. Known differences in the 200-mg versus 50-mg formulations were captured by covariate modeling. Further studies are needed to validate the structural model and confirm covariate relationships. (This study has been registered with the ISRCTN Registry under no. ISRCTN96948551.)

Antipsychotic Medication Use in the Elderly Patient

The use of antipsychotic medications in the elderly can be very complex and is ever changing. Consideration must be given to not only the physiologic and functional changes normally associated with age but also to the latest data on safety and adverse outcomes associated with using these agents. Because of new and changing information, this article will review the effects of aging, side effects of antipsychotic medications, and the current issues surrounding their use in elderly patients for those clinicians who are not specialists in this area of practice.

A systematic study on drug-response associated genes using baseline gene expressions of the Cancer Cell Line Encyclopedia

We have studied drug-response associated (DRA) gene expressions by applying a systems biology framework to the Cancer Cell Line Encyclopedia data. More than 4,000 genes are inferred to be DRA for at least one drug, while the number of DRA genes for each drug varies dramatically from almost 0 to 1,226. Functional enrichment analysis shows that the DRA genes are significantly enriched in genes associated with cell cycle and plasma membrane. Moreover, there might be two patterns of DRA genes between genders. There are significantly shared DRA genes between male and female for most drugs, while very little DRA genes tend to be shared between the two genders for a few drugs targeting sex-specific cancers (e.g., PD-0332991 for breast cancer and ovarian cancer). Our analyses also show substantial difference for DRA genes between young and old samples, suggesting the necessity of considering the age effects for personalized medicine in cancers. Lastly, differential module and key driver analyses confirm cell cycle related modules as top differential ones for drug sensitivity. The analyses also reveal the role of TSPO, TP53, and many other immune or cell cycle related genes as important key drivers for DRA network modules. These key drivers provide new drug targets to improve the sensitivity of cancer therapy.

Age as a predictor of rescue opioid administration immediately after the emergence of general anesthesia

BACKGROUND AND OBJECTIVES

While previous studies have shown that elderly patients require lower dosages of opioids, the literature suggests that pain is undertreated in the geriatric population, which may lead to postoperative pain and high rescue analgesia requirements. The purpose of this study is to determine whether elderly patients undergoing hip and knee arthroplasty require higher levels of postoperative rescue opioids than their younger counterparts early after emergence from anesthesia.

METHODS

Using a nonconcurrent retrospective cohort study design, patients who underwent hip or knee arthroplasty under general anesthesia at a tertiary academic hospital from 2007 to 2012 were identified. Demographic information and data regarding patients' anesthetic care were obtained from the institution's anesthesia information management system. To assess the presence of pain after the emergence of anesthesia, we used, as a proxy, opioid administration by the anesthesia provider after leaving the operating room and before the end of anesthesia care.

RESULTS

A total of 2731 patients met inclusion criteria, of which 487 (17.8%) received rescue opioids. Patients older than 80 years were less likely to receive opioids after leaving the operating room (odds ratio, 0.57; 95% confidence interval, 0.37-0.88; P = .01) and received 1.37 mg less of hydromorphone equivalent opioid compared to patients younger than the age of 50 years (95% confidence interval, 1.18-1.55; P < .001). The proportion of patients who received rescue opioids varied significantly between anesthesia providers from 0% to 38% (P < .001).

CONCLUSIONS

While elderly patients received lower doses of opioids intraoperatively, they were less likely to require rescue analgesia. The variability among providers in rescue opioid administration after emergence presents an opportunity for further research.

Sleep disorders and fatigue: special issues in the older adult with cancer

Older adults with cancer reporting fatigue and sleep disorders often have coexisting geriatric syndromes and are at high risk of further functional decline. This review summarizes special considerations in the diagnosis and treatment of sleep disorders and fatigue when older persons with cancer present with multiple comorbidities, polypharmacy, dementia, delirium, and/or falls. Physicians caring for these older adults need to be aware of the unique diagnostic and treatment concerns in this population so that these patients can receive optimal care.

Pharmacokinetics and pharmacodynamics of psychotropic drugs: effect of sex

Data on the specific effects of sex on pharmacokinetics, as well as tolerability, safety, and efficacy of psychotropic medications are still meager, mainly because only recently sex-related issues have attracted a certain degree of interest within the pharmacological domain. Therefore, with the present study, we aimed to provide a comprehensive review of the literature on this topic, through careful MEDLINE and PubMed searches of the years 1990-2012. Generally, data on pharmacokinetics are more consistent and numerous than those on pharmacodynamics. Sex-related differences have been reported for several parameters that influence pharmacokinetics, such as gastric acidity, intestinal motility, body weight and composition, blood volume, liver enzymes (mainly the cytochrome P450), or renal excretion, which may alter plasma drug levels. Sex-related peculiarities may also account for a different sensitivity of men and women to side effects and toxicity of psychotropic drugs. Further, some differences in drug response, mainly to antipsychotics and antidepressants, have been described. Further studies are, however, necessary to explore more thoroughly the impact of sex on the pharmacokinetics and pharmacodynamics of psychotropic drugs, in order to reach the most appropriate and tailored prescription for each patient.

Functional status determines postoperative outcomes in elderly patients undergoing hepatic resections

BACKGROUND

With the aging population and increasing incidence of hepatic malignancies in elderly patients, establishing the safety of hepatic resections is crucial. The present study investigates early postoperative morbidity and mortality in elderly patients undergoing hepatic resection using a nationally validated database.

METHODS

The National Surgical Quality Improvement Program Participant User Files (NSQIP-PUF) for 2005-2009 were used for the retrospective analysis of all patients undergoing hepatic resection. The primary outcome measures were 30-day postoperative mortality, overall complication rate, and serious complication rate. The primary predictor variable was patient age, which was treated as a dichotomous variable (age ≤ 70 years, age ≥ 70 years).

RESULTS

Five thousand seven hundred six patients were included in the final analysis, 1,280 of which were ≥ 70 years of age. Thirty-day postoperative mortality (≤ 70 years 1.9% vs. ≥ 70 years 4.5%, P < 0.0001), serious complications (≤ 70 years 15.2% vs. ≥ 70 years 18.4%, P < 0.006) and overall complications (≤ 70 years 23.1% vs. ≥ 70 years 26.6%, P < 0.01) were more common in the elderly group. Elderly patients had significantly more wound infections, pneumonia, prolonged ventilator support, unplanned re-intubations, renal failure, strokes, myocardial infarction, cardiac arrests, and septic shock. The median length of hospitalization was also significantly longer in the elderly.

CONCLUSIONS

This study shows significantly higher complication rates and mortality following hepatic resections in elderly patients. These findings should be taken into account when considering hepatectomy in this population.

A review of the evidence concerning hepatic glutathione depletion and susceptibility to hepatotoxicity after paracetamol overdose

Paracetamol (acetaminophen) poisoning is common throughout the world. The management of nonstaggered (acute) paracetamol overdose is based on the plasma paracetamol concentration plotted on a treatment nomogram. In the UK there are two treatment lines on this nomogram, with the lower treatment line used for individuals felt to be at ‘high risk’ of paracetamol-related hepatotoxicity either as a result of induction of cytochrome P450 isoenzymes or reduction of intrahepatic glutathione. In this article we review the risk factors that, in current guidelines, are felt to increase risk due to a reduction in intrahepatic glutathione concentrations. Based on our review of the published literature, we feel that cystic fibrosis, acute viral illness, malnutrition, and eating disorders such as anorexia nervosa are likely to be associated with reduction in intrahepatic glutathione concentrations, and that this risk is likely to be related to malnutrition secondary to the disease. Chronic hepatitis C infection is also associated with reduced glutathione concentrations, although this appears to be independent of any associated malnutrition. Ageing and acute fasting are not associated with an increased risk of paracetamol-related hepatotoxicity due to reductions in glutathione concentrations. Finally, the evidence for HIV infection is inconclusive, particularly as the majority of studies were conducted in the pre-anti-viral treatment (HAART) era; however it is likely that patients with symptomatic HIV/AIDS have reduced glutathione concentrations due to associated malnutrition. Although there have been few studies which have specifically investigated whether there is an association between reduced intrahepatic glutathione concentrations and increased risk of paracetamol-related hepatotoxicity, in our opinion, it is likely that the above conditions that are associated with reduced glutathione concentrations, will be associated with an increased risk of paracetamol-related hepatotoxicity.

Evaluation of trimetazidine in angina pectoris by echocardiography and radionuclide angiography: a meta-analysis of randomized, controlled trials

BACKGROUND

The objective of this meta-analysis was to evaluate the efficacy of the metabolic agent trimetazidine (TMZ) as monotherapy in the treatment of stable angina pectoris, from echocardiography and radionuclide angiography data.

HYPOTHESIS

Treatment with TMZ proved to be as effective as other first-line antianginal agents for coronary patients, and it provided additional efficacy in combination with hemodynamic agents.

METHODS

A search of the literature published between 1965 and 2008 was performed on the MEDLINE and EMBASE databases. Only randomized, controlled trials were included in this meta-analysis. Patients had to be treated for at least 2 weeks with data on the following 4 parameters at baseline and at the end of the treatment period: left ventricular ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and wall motion score index (WMSI). The quality of the trials was assessed by the Jadad score.

RESULTS

Eleven clinical studies meeting our criteria were analyzed. Results showed that TMZ significantly improved LVEF, with a mean increase of 6.88% (95% confidence interval [CI]: 5.50-8.25), and significantly reduced LVESV by 11.58 mL (95% CI: 5.79-17.37) and WMSI by 0.23 (95% CI: 0.07-0.38). Changes in LVEDV were variable. In both the long term and the short term, TMZ can improve LV function. The efficacy was unchanged in patients with diabetes mellitus.

CONCLUSIONS

This meta-analysis confirmed the efficacy of TMZ monotherapy in improving LV function compared with placebo.

Elderly and drugs: risks and necessity of rational use

In recent decades, the world has undergone a demographic transformation with a rapid growth of the elderly population, resulting in an increased demand for funds to maintain their health and drug consumption. Pharmacokinetic and pharmacodynamic changes occurring in the elderly can interfere directly in the adverse effects of drugs and increase the risk of intoxication. In addition, there are external factors interfering with the pharmacotherapy of the elderly, such as inappropriate use and the lack of access to information. Many therapeutic classes of drugs should be used with caution or avoided in the elderly population, such as anti-inflammatory and some anti-hypertensive drugs, diuretics and digitalis. If not managed carefully, these medicines can affect the safety and quality of life in the elderly. Thus, the aim of this review was to identify drugs that should be used with caution in elderly patients in order to avoid intoxication and/or adverse drug events.

Diagnosis and management of chronic liver disease in older people

Chronic liver disease is increasingly prevalent and, as the population ages, geriatricians will see an increasing burden. We present an overview of the investigation and management of older adults with chronic parenchymal liver disease and highlight the potential roles of transjugular intrahepatic portosytemic shunts and orthotopic liver transplantation.

Phenacetin and chlorzoxazone biotransformation in aging male Fischer 344 rats

We evaluated the role of specific isoforms in the biotransformation of phenacetin and chlorzoxazone and examined the effect of age on these reactions using liver microsomes from Fischer 344 rats between 3 and 26 months of age. Using rat cDNA-expressed cytochrome P450 (CYP) enzymes, we found that phenacetin biotransformation was primarily mediated by CYP2C6 and CYP1A isoforms, while chlorzoxazone biotransformation was largely mediated by CYP2E1 and CYP1A1. Incubations with liver microsomes prepared from rats of varying ages demonstrated that both phenacetin and chlorzoxazone biotransformation declined with age. Metabolite formation rates in the old rats (25–26 months) were reduced by approximately 60–70% for these reactions. This study suggests that the activity of CYP2E and CYP1A enzymes decline with age in the rat liver. Also, the relative specificity of the index substrates phenacetin (for CYP1A2) and chlorzoxazone (for CYP2E1) in man appears not to be applicable in rats.

Effects of aging on pharmacokinetic and pharmacodynamic drug processes

Aging affects the pharmacokinetics and pharmacodynamics of drugs, which has potentially important implications for the use of psychotropic medication in older adults. The absorption of orally administered drugs may be impaired or delayed, the volume of distribution of most drugs is decreased, and over time, the distribution shifts toward greater drug accumulation in fat stores. Decrease in renal function with age is especially important regarding the use of lithium but is also relevant for most drugs because they are eventually cleared through the kidneys after metabolism in the liver. Because pharmacodynamic changes associated with aging will make elderly patients more sensitive to the pharmacological effects of medication-especially adverse effects-nurses should be appropriately trained in pharmacology and therapeutics in older adults.

Multicenter safety study of mFOLFOX6 for unresectable advanced/recurrent colorectal cancer in elderly patients

Background

Combination chemotherapy with oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX) has become a standard regimen for colorectal cancer. An increase of adverse events with combination chemotherapy is predicted in elderly patients, and it remains controversial whether they should receive the same chemotherapy as younger patients. Accordingly, this study of modified FOLFOX6 (mFOLFOX6) therapy was performed to compare its safety between elderly and non-elderly patients.

Methods

We prospectively studies 14 non-elderly patients aged <70 years old and 8 elderly patients aged ≥ 70 years with unresectable advanced/recurrent colorectal cancer who received mFOLFOX6 therapy during the period from March 2006 to March 2007. Adverse events and the response to treatment were compared between the elderly and non-elderly groups.

Results

The main adverse events were neutropenia and peripheral neuropathy, which occurred in 62.5% (≥ grade 3) and 87.5% (≥ grade 1) of elderly patients. The grade and frequency of adverse events were similar in the elderly and non-elderly groups. In some patients with neutropenia, treatment could be continued without reducing the dose of oxaliplatin by deleting bolus 5-fluorouracil. A correlation was found between the cumulative dose of oxaliplatin and the severity of neuropathy, and there were 2 elderly and 3 younger patients in whom discontinuation of treatment was necessary due to peripheral neuropathy. The median number of treatment cycles was 10.0 and 9.5 in the non-elderly and elderly groups, respectively. The response rate was 60.0% in the non-elderly and 50.0% in the elderly group, while the disease control rate was 100% and 83.3% respectively, showing no age-related difference.

Conclusion

mFOLFOX6 therapy was well-tolerated and effective in both non-elderly and elderly patients. However, discontinuation of treatment was sometimes necessary due to peripheral neuropathy, which is dose-limiting toxicity of this therapy.

Population analyses of atorvastatin clearance in patients living in the community and in nursing homes

The effects of demographic and clinical covariates on the apparent clearance (CL/F) of orally administered atorvastatin, with chronic dosing in a patient population that included the elderly, were studied in 143 patients (atorvastatin: 34 +/- 26 mg/day, mean +/- SD; men (n = 64), age 64.6 +/- 12.1 years, and women (n = 79), age 69.3 +/- 13 years). The time of dose administration had a strong influence on Ka (faster with morning dosing); the factors found to slow CL/F were coadministration of CYP3A inhibitors and advancing age--the latter factor was relevant only in the men, not in the women.

Intake of drugs among elderly people in a Danish municipality, Rødovre

Drug intake has been studied among a random group of persons, aged 75 or over, in Rødovre Municipality. Two hundred and eight-three elderly persons living in their own homes have been visited and interviewed about their daily intake of prescribed and nonprescribed drugs (including so-called natural drugs). Similar information was gathered from 146 elderly persons living in nursing homes. Thirty-one per cent of the elderly living in their own homes and 3% of those living in nursing homes did not use prescribed drugs daily. The median daily amount of different types of drugs used was 1.8 (range 0-10) for elderly persons living in their own homes and 4.5 (range 0-11) (p less than 0.001) for those living in nursing homes. Women living at home had a higher intake of drugs than men, especially diuretics. The most frequently used drugs were diuretics, sedatives/hypnotics, analgesics, digitalis and electrolytes. For all types of drugs a higher consumption, especially of phenothiazines, was found among elderly persons living in nursing homes. Drug consumption was independent of age and social stratification in both groups. The use of non-prescribed drugs ranges from 0 to 9 different types in the group living in their own homes, and from 0 to 5 in the group living in nursing homes--laxatives being the type most frequently used.

Drug treatment in 70-82-year-old persons. A longitudinal study

The drug consumption has been studied in two 70-year-old cohorts within the frames of the longitudinal population study "70-year-old people in Göteborg, Sweden". The first cohort has been followed for 12 years and the second, which was born 5 years later, for 5 years. In the first cohort the proportion of men and women on drug treatment increased from 61 and 77% at age 70 to 90 and 97% at age 82. The average number of drugs among those on treatment increased from 3.1 (men) and 3.4 (women) to 3.9 and 5.4, respectively. The most common drugs at age 70 were anxiolytics (20 and 29%), diuretics (15 and 29%), analgesics (12 and 20%), and digitalis (13 and 14%) and at 82 years of age analgesics (39 and 56%), anxiolytics (27 and 49%), diuretics (26 and 42%), and laxatives (19 and 28%). The second examined cohort used more drugs mainly at age 75 than the first cohort. The longitudinal follow-up of the first cohort indicated an overmortality mainly among men on drug treatment at ages 70 and 75. The patients' knowledge of the indications for the treatment was often weak and at age 82, 25% of the patients were unaware of the indications for one or more of the drugs.

The safety of clozapine in the elderly

BACKGROUND

Clozapine was the first atypical 'broad spectrum' antipsychotic drug to be marketed and the first agent approved for the treatment of schizophrenia refractory to other medications. It is also effective for the treatment of aggressive behaviour in schizophrenic and demented patients and in the management of psychosis and aggression in Parkinson's disease and Lewy body dementia.

OBJECTIVE

The aim of this review is to study the safety of clozapine for use in elderly patients.

METHODS

An extensive Medline search was made. Some studies that were referenced in reports from our pharmacovigilance centre and from regulatory agencies such as the FDA, EMEA and WHO were included.

CONCLUSIONS

Clozapine treatment in the elderly requires a careful geriatric assessment. However, its use is strongly limited by the possibility of onset of severe adverse effects such as potentially fatal agranulocytosis, myocarditis and others such as seizures, weight gain and metabolic adverse effects.

What limits for acute care in the elderly?

PURPOSE OF REVIEW

This review aims to address the important question of the increasing life expectancy and the aging population in the healthcare system today. We try to give some elements that will help the reflection about the ethical stakes balancing the necessity of care in the increasing number of elderly patients and the limited resources available, in the special context of acute care.

RECENT FINDINGS

There is growing evidence that the chronological age itself is not a reliable marker of bad prognosis or of mortality. The new concept of frailty may better correlate with the aging process of the elderly. The frailty index is an integrative approach considering the multiple factors impacting on the aging individual. Applied in the practical arena, it might become a useful tool for clinicians.

SUMMARY

Aging implies many biological modifications at molecular, cellular, organic levels as well as of the behavior. Some aspects of these processes and their consequences on health are described. The frailty concept is detailed, and its potential interest explained. We conclude that the measurement of aging phenomenon, including the frailty index, may help us to better assess the true health and the required therapeutics of elderly patients.