Impact of cachexia on pharmacokinetic disposition of and clinical responses to oxycodone in cancer patients

The Glasgow Prognostic Score as a Predictor of Survival after Chemoradiotherapy for Limited-Disease Small Cell Lung Cancer

INTRODUCTION

Established biomarkers for predicting chemoradiotherapy efficacy for limited-disease small cell lung cancer (LD-SCLC) are lacking. The inflammation-based Glasgow Prognostic Score (GPS), comprising serum C-reactive protein (CRP) and albumin levels, can predict survival in advanced cancer. This study investigated whether metabolic and inflammatory markers, including the GPS, can predict the efficacy of chemoradiotherapy in patients with LD-SCLC.

METHODS

We retrospectively analyzed 124 patients who underwent chemoradiotherapy for LD-SCLC at two institutions between April 2007 and June 2021, and assessed the prognostic significance of various metabolic and inflammatory markers. The GPS was calculated using the CRP and albumin concentrations, and categorized as follows: 0, CRP <1.0 mg/dL and albumin ≥3.5 mg/dL; 1, elevated CRP or decreased albumin; and 2, CRP ≥1.0 mg/dL and albumin<3.5 mg/dL. Differences in progression-free survival (PFS) and overall survival (OS) were examined using Kaplan-Meier curves and Cox proportional-hazard models.

RESULTS

The overall response rate was 95.1% (95% confidence interval [CI]: 89.6-97.9%). The median PFS and OS from chemoradiotherapy initiation were 12.6 (95% CI: 9.9-15.4) and 29.0 (95% CI: 24.8-45.5) months, respectively. The GPS demonstrated independent predictive ability for the effectiveness of chemoradiotherapy, wherein favorable scores (GPS 0-1) were significantly correlated with superior PFS and OS compared to unfavorable scores (GPS 2: PFS: 14.8 vs. 6.7 months, p = 0.0001; OS: 35.4 vs. 11.0 months, p < 0.0001).

CONCLUSION

This preliminary examination revealed that the GPS was significantly associated with PFS and OS in patients undergoing chemoradiotherapy for LD-SCLC, indicating its potential utility in assessing the therapeutic outcomes in LD-SCLC.

Diagnosis and outcomes of cachexia in Asia: Working Consensus Report from the Asian Working Group for Cachexia

Chronic diseases often lead to metabolic disorders, causing anabolic resistance and increased energy consumption, which result in cachexia. Cachexia, in turn, can lead to major clinical consequences such as impaired quality of life, shortened life expectancy, and increased healthcare expenditure. Existing international diagnostic criteria for cachexia employ thresholds derived from Western populations, which may not apply to Asians due to differing body compositions. To address this issue, the Asian Working Group for Cachexia (AWGC) was initiated. The AWGC comprises experts in cachexia research and clinical practice from various Asian countries and aims to develop a consensus on diagnostic criteria and significant clinical outcomes for cachexia in Asia. The AWGC, composed of experts in cachexia research and clinical practice from several Asian countries, undertook three-round Delphi surveys and five meetings to reach a consensus. Discussions were held on etiological diseases, essential diagnostic items for cachexia, including subjective and objective symptoms and biomarkers, and significant clinical outcomes. The consensus highlighted the importance of multiple diagnostic factors for cachexia, including chronic diseases, either or both weight loss or low body mass index, and at least one of the following: anorexia, decreased grip strength (<28 kg in men and <18 kg in women), or elevated C-reactive protein levels (>5 mg/L [0.5 mg/dL]). The AWGC proposed a significant weight change of 2% or more over a 3-6 month period and suggested a tentative cut-off value of 21 kg/m2 for low body mass index in diagnosing cachexia. Critical clinical outcomes were determined to be mortality, quality of life as assessed by tools such as EQ-5D or the Functional Assessment of Anorexia/Cachexia Therapy, and functional status as measured by the Clinical Frailty Scale or Barthel Index, with significant emphasis on patient-reported outcomes. The AWGC consensus offers a comprehensive definition and user-friendly diagnostic criteria for cachexia, tailored specifically for Asian populations. This consensus is set to stimulate future research and enhance the multidisciplinary approach to managing cachexia. With plans to develop further guidelines for the optimal treatment, prevention, and care of cachexia in Asians, the AWGC criteria are expected to drive research across chronic co-morbidities and cancer in Asia, leading to future refinement of diagnostic criteria.

Pretreatment glasgow prognostic score predicts survival among patients administered first-line atezolizumab plus carboplatin and etoposide for small cell lung cancer

Background

There are no established predictive biomarkers for the effectiveness of first-line atezolizumab plus carboplatin and etoposide therapy in patients with small-cell lung cancer (SCLC). Therefore, the current study aimed to investigate whether the Glasgow prognostic score (GPS), neutrophil-to-lymphocyte ratio (NLR), and body mass index (BMI) can predict the effectiveness of first-line atezolizumab plus carboplatin and etoposide therapy in patients with extensive-disease SCLC.

Methods

We reviewed data from 84 patients who received first-line atezolizumab plus carboplatin and etoposide therapy for SCLC at nine Japanese institutions between August 2019 and May 2021. Further, we evaluated the prognostic value of the GPS, NLR, and BMI. The Kaplan-Meier and Cox proportional hazard models were used to examine differences in progression-free survival (PFS) and overall survival (OS). Moreover, the GPS, NLR, and BMI consisted of C-reactive protein and albumin concentrations, neutrophil and lymphocyte counts, and body weight and height, respectively.

Results

The response rate was 72.6% (95% confidence interval: 63.0-82.1%). The median PFS and OS from the initiation of treatment were 5.4 (95% CI: 4.9-5.9) months and 15.4 (95% CI: 11.4-16.8) months, respectively. The GPS independently predicted the effectiveness of first-line atezolizumab plus carboplatin and etoposide treatment, as a favorable GPS (GPS 0-1) was correlated with significantly better PFS and OS rates compared to a poor GPS (GPS 2) (PFS: 5.8 vs. 3.8 months, p = 0.0005; OS: 16.5 vs. 8.4 months, p<0.0001).

Conclusions

This is the first analysis to evaluate the association between the GPS, NLR, and BMI and the treatment effectiveness of survival among patients receiving first-line atezolizumab plus carboplatin and etoposide therapy for SCLC. Among patients receiving this treatment for SCLC, GPS was significantly associated with the PFS and OS rates, suggesting that GPS might be useful for evaluating therapeutic outcomes in these patients.

Integrated UPLC-MS and Network Pharmacology Approach to Explore the Active Components and the Potential Mechanism of Yiqi Huoxue Decoction for Treating Nephrotic Syndrome

Background: Yiqi Huoxue Decoction (YQHXD) is a traditional Chinese medicine that promotes blood circulation, removes blood stasis, facilitates diuresis, and alleviates edema. It is composed of 10 herbal medicines and has extensive application in treating nephrotic syndrome (NS). However, the active components and the potential mechanism of YQHXD for treating NS remain unclear.

Methods: We set up a sensitive and rapid method based on Ultra-High Performance Liquid Chromatograph-Mass (UPLC-MS) to identify the compounds in YQHXD and constituents absorbed into the blood. Disease genes were collected through GeneCards, DisGeNET, and OMIM database. Genes of compounds absorbed into blood were predicted by the TCMSP database. We constructed Disease-Drug-Ingredient-Gene (DDIG) network using Cytoscape, established a Protein-protein interaction (PPI) network using String, Gene biological process (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed using DAVID. Cellular experiments were performed to validate the results of network pharmacology.

Result: A total of 233 compounds in YQHXD and 50 constituents absorbed into the blood of rats were identified. The 36 core targets in the PPI network were clustered in the phosphatidylinositol 3 kinase-RAC serine/threonine-protein kinase (PI3K-AKT) and nuclear factor kappa-B (NF-κB) signaling pathways. Luteolin, Wogonin, Formononetin, and Calycosin were top-ranking components as potentially active compounds.

Conclusion: The results of our studies show that YQHXD is able to enhance renal function, alleviate podocyte injury, and improve adriamycin nephrotic syndrome.

Involvement of the Parathyroid Hormone-Related Protein on Changes in the CYP3A Expression in Cancer Cachexia

Parathyroid hormone-related protein (PTHrP), which is secreted from a tumor, contributes to the progression of cachexia, a condition that is observed in half of all cancer patients. Although drug clearance was reported to decrease in patients with cancer cachexia, the details have not been clarified. The present study reports on an investigation of whether PTHrP is involved in the alternation of drug metabolism in cases of cancer cachexia. Cancer cachexia model rats with elevated serum PTHrP levels showed a significant decrease in hepatic and intestinal CYP3A2 protein expression. When midazolam, a CYP3A substrate drug, was administered intravenously or orally to the cancer cachexia rats, its area under the curve (AUC) was increased by about 2 and 5 times, as compared to the control group. Accordingly, the bioavailability of midazolam was increased by about 3 times, thus enhancing its pharmacological effect. In vitro experiments using HepG2 cells and Caco-2 cells showed that the addition of serum from cancer cachexia rats or active PTHrP (1-34) to each cell resulted in a significant decrease in the expression of CYP3A4 mRNA. Treatment with a cell-permeable cAMP analog also resulted in a decreased CYP3A4 expression. Pretreatment with protein kinase A (PKA), protein kinase C (PKC), and nuclear factor-kappa B (NF-κB) inhibitors recovered the decrease in CYP3A4 expression that was induced by PTHrP (1-34). These results suggest that PTHrP suppresses CYP3A expression via the cAMP/PKA/PKC/NF-κB pathway. Therefore, it is likely that PTHrP would be involved in the changes in drug metabolism observed in cancer cachexia.

Pretreatment Glasgow prognostic score predicts survival among patients with high PD-L1 expression administered first-line pembrolizumab monotherapy for non-small cell lung cancer

BACKGROUND

There are no established biomarkers for predicting the efficacy of first-line pembrolizumab monotherapy in patients with high programmed death-ligand 1 (PD-L1) expression. In this study, we investigated whether the Glasgow prognostic score (GPS), neutrophil-to-lymphocyte ratio (NLR), and body mass index (BMI) can be used to evaluate the effect of first-line pembrolizumab monotherapy in patients with advanced non-small cell lung cancer (NSCLC) who express high levels of PD-L1.

METHODS

We reviewed data from 142 patients with high PD-L1 expression who underwent first-line pembrolizumab monotherapy for NSCLC at six Japanese institutions between February 2017 and June 2019 and assessed the prognostic value of the GPS, NLR, and BMI. The Kaplan-Meier method and Cox proportional hazard models were used to examine differences in progression-free survival (PFS) and overall survival (OS). The GPS, NLR, and BMI were calculated using C-reactive protein and albumin concentrations, neutrophil and lymphocyte counts, and body weight and height, respectively.

RESULTS

The GPS independently predicted the first-line pembrolizumab monotherapy efficacy, as a good GPS (GPS 0-1) was associated with a significantly better PFS and OS compared to a poor GPS (GPS 2) (PFS: 11.8 vs. 2.9 months, p < 0.0001; OS: not reached vs. 8.3 months, p < 0.0001). Furthermore, BMI independently predicted efficacy, as patients with high BMI (BMI ≥21.4) exhibited significantly better OS compared to those with low BMI (BMI <21.4) (OS: not reached vs. 14.1 months, p = 0.006).

CONCLUSIONS

Among patients with high PD-L1 expression undergoing first-line pembrolizumab monotherapy for NSCLC, the GPS is significantly correlated with both PFS and OS, and BMI with OS, indicating that they could be used to predict treatment outcome in these patients. To the best of our knowledge, this is the first study to assess the relationship among the GPS, NLR, and BMI and survival among patients with high PD-L1 expression undergoing first-line pembrolizumab monotherapy for NSCLC.

Genetics and Opioids: Towards More Appropriate Prescription in Cancer Pain

Opioids are extensively used in patients with cancer pain; despite their efficacy, several patients can experience ineffective analgesia and/or side effects. Pharmacogenetics is a new approach to drug prescription based on the “personalized-medicine” concept, i.e., the ability of tailoring treatments to each individual’s genetic/genomic profile. Pharmacogenetics aims to identify specific genetic variants that influence pharmacokinetics and pharmacodynamics of drugs, better determining their effectiveness/safety profile. Opioid response is a complex scenario, but some gene variants have shown a correlation with pain sensitivity, as well as with opioid metabolism and clinical efficacy/adverse events. Although questions remain unanswered, some of these gene variants may already be used to identify specific patients’ phenotypes that are more prone to experience better clinical response (i.e., better analgesia and/or less adverse events). Once adopted, this approach to opioid prescription may improve a patient’s outcome. This review summarizes the available data on genetic variants and opioid response: we will focus on basic pharmacogenetic and its impact in the clinical scenario discussing how they may lead to more appropriate opioid prescription in cancer patients.

Glasgow prognostic score predicts efficacy and prognosis in patients with advanced non-small cell lung cancer receiving EGFR-TKI treatment

Background

Lung cancer is the leading cause of cancer‐related deaths. Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) are effective for advanced non‐small cell lung cancer (NSCLC) harboring EGFR mutations, some patients experience little or no response. The Glasgow prognostic score (GPS) is an inflammation‐related score based on C‐reactive protein (CRP) and albumin concentrations, and has prognostic value in various cancer settings. This study aimed to evaluate whether GPS could predict response of NSCLC to EGFR‐TKIs.

Methods

This retrospective multicenter study evaluated patients with NSCLC harboring EGFR mutations who received EGFR‐TKI monotherapy from October 2006 to December 2016. GPS values were determined using CRP and albumin concentrations from before initiation of EGFR‐TKIs. The Kaplan‐Meier method and Cox proportional hazard models were used to evaluate progression‐free survival (PFS) and overall survival (OS).

Results

In 214 patients, 141, 43, and two patients had GPS values of 0, 1, and 2, respectively. The GPS independently predicted the efficacy of EGFR‐TKIs; good GPS (0–1) conferred significantly better PFS (hazard ratio [HR]: 0.59, 95% confidence interval [CI]: 0.38–0.96, P = 0.03) and OS (HR: 0.56, 95% CI: 0.33–0.96, P = 0.03). Multivariate analysis confirmed that a good GPS (0–1) independently predicted good PFS and OS among patients who had PS of 0–1. Good GPS (0–1) independently predicted good OS among patients receiving treatment in first‐line settings.

Conclusions

The GPS independently predicted the efficacy of EGFR‐TKIs for EGFR‐mutated NSCLC; however, further studies are needed to validate our findings.

Key points

Significant findings of the study

Glasgow prognostic score (GPS) independently predicted the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR‐TKIs) treatment for EGFR‐mutated NSCLC.

What this study adds

The findings presented in this paper will help to identify patients who will be expected to experience limited or no response to EGFR‐TKI treatment by using GPS.

Impact of Cachexia and Opioid Analgesic Cotreatment on Pregabalin Pharmacokinetics and Central Nervous System Symptoms in Cancer Patients

BACKGROUND

Patients with cancer receiving pregabalin potentially have a high incidence of central nervous system (CNS) symptoms. The purpose of this study was to explore clinical factors influencing the incidence of CNS symptoms, including plasma pregabalin exposure, cancer cachexia, and opioid analgesic cotreatment.

METHODS

Sixty-eight patients with cancer receiving twice-daily pregabalin were enrolled. Plasma concentrations of pregabalin, clinical laboratory data, opioid analgesic cotreatment, and the Glasgow Prognostic Score, which is an inflammation-based cachexia score, were considered as clinical factors. The incidence of CNS symptoms was collected from the patients' medical records. The predose plasma concentrations of pregabalin at steady state were determined by ultra-high-performance liquid chromatography.

RESULTS

The steady-state trough plasma pregabalin concentrations showed a large variability with an interquartile range of 0.43-1.2 mg/L per mg/kg and were negatively correlated with an estimated glomerular filtration rate (eGFR). C-reactive protein (standardized partial regression coefficient, β = 0.31) and opioid analgesic cotreatment (β = 0.24) were also identified in addition to eGFR (β = -0.60) in the multiple regression analysis. The incidence of CNS symptoms was significantly increased with opioid analgesic cotreatment and a higher Glasgow Prognostic Score but not with the absolute value of plasma pregabalin concentrations, eGFR, or other clinical laboratory data.

CONCLUSIONS

In patients with cancer, steady-state trough plasma pregabalin concentrations were altered with renal function, systemic inflammation, and opioid analgesic cotreatment. However, a higher incidence of CNS symptoms observed in patients with cancer on pregabalin was more related to cachexia and opioid analgesic cotreatment than to altered pregabalin concentrations.

Pharmacokinetics of Intravenous Isavuconazole in Solid-Organ Transplant Recipients

Isavuconazole may be useful in treating and preventing fungal infections in solid-organ transplant (SOT) recipients due to its safety profile and activity against Aspergillus and some Mucorales Isavuconazole has favorable pharmacokinetics based on clinical trials in various patient populations, but data are limited in SOT recipients. We evaluated the steady-state pharmacokinetics of isavuconazole in 26 SOT recipients receiving the drug intravenously for prophylaxis. There was moderate interpatient variability in isavuconazole pharmacokinetic parameters (coefficients of variation of 51% for the area under the plasma concentration-versus-time curve [AUC] and 59% for the trough plasma concentration [C _trough]). AUC and steady-state C _trough were significantly lower in women, patients with a body mass index of ≥18.5 kg/m², and those receiving hemodialysis. Trough plasma concentrations were highly correlated with AUCs (R ² = 0.94) and can serve as a suitable measure of isavuconazole exposure in patients. In conclusion, moderate interpatient variability in isavuconazole exposure, the identification of factors associated with lower exposure, the recognition that C _trough is a surrogate marker for AUC, and the availability of a simple analytical method suggest that therapeutic drug monitoring (TDM) may be useful for guiding treatment in at least some SOT recipients. Future studies are needed to correlate isavuconazole exposure with patients' clinical outcomes and to determine the clinical role of TDM.

Elevated 4β-hydroxycholesterol/cholesterol ratio in anorexia nervosa patients

Recent studies have shown that the cytochrome P450 (CYP) 3A phenotype marker 4β-hydroxycholesterol/cholesterol (4βOHC/C) ratio is negatively correlated with body weight in healthy volunteers, and that obese patients have lower 4βOHC levels than healthy controls. However, 4βOHC/C ratio in underweight patients has yet to be reported. The aim of this study was to examine potential differences in CYP3A activity between underweight patients with anorexia nervosa and normal-weight volunteers by measuring plasma 4βOHC/C ratio. Furthermore, we wished to describe any association between body mass index (BMI) and 4βOHC/C ratio in underweight patients. A total of 20 underweight patients and 16 normal-weight volunteers were included in the study, all females. Underweight patients had a median 4βOHC/C ratio (molar ratio × 10-5) of 2.52 (range, 0.90-11.3) compared to 1.29 (0.56-2.09) in normal-weight subjects (Mann-Whitney P = 0.0005). 4βOHC/C ratio was negatively correlated with BMI in underweight patients (r = -0.56, P = 0.011), and in the whole study population (r = -0.67, P < 0.0001). This suggests that the negative correlation between 4βOHC/C and BMI, which has previously been reported between 4βOHC/C and body weight in healthy volunteers, extends to underweight patients. The findings indicate that CYP3A activity increases with decreasing BMI, resulting in higher CYP3A activity in underweight patients compared to normal-weight subjects. The potential clinical relevance of this needs to be studied further by comparing pharmacokinetics of drugs subjected to CYP3A-mediated metabolism in underweight vs. normal-weight individuals.

A systematic review of the risk factors for clinical response to opioids for all-age patients with cancer-related pain and presentation of the paediatric STOP pain study

BACKGROUND

Inter-patient variability in response to opioids is well known but a comprehensive definition of its pathophysiological mechanism is still lacking and, more importantly, no studies have focused on children. The STOP Pain project aimed to evaluate the risk factors that contribute to clinical response and adverse drug reactions to opioids by means of a systematic review and a clinical investigation on paediatric oncological patients.

METHODS

We conducted a systematic literature search in EMBASE and PubMed up to the 24th of November 2016 following Cochrane Handbook and PRISMA guidelines. Two independent reviewers screened titles and abstracts along with full-text papers; disagreements were resolved by discussion with two other independent reviewers. We used a data extraction form to provide details of the included studies, and conducted quality assessment using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies.

RESULTS

Young age, lung or gastrointestinal cancer, neuropathic or breakthrough pain and anxiety or sleep disturbance were associated to a worse response to opioid analgesia. No clear association was identified in literature regarding gender, ethnicity, weight, presence of metastases, biochemical or hematological factors. Studies in children were lacking. Between June 2011 and April 2014, the Italian STOP Pain project enrolled 87 paediatric cancer patients under treatment with opioids (morphine, codeine, oxycodone, fentanyl and tramadol).

CONCLUSIONS

Future studies on cancer pain should be designed with consideration for the highlighted factors to enhance our understanding of opioid non-response and safety. Studies in children are mandatory.

TRIAL REGISTRATION

CRD42017057740 .

Cachexia research in Japan: facts and numbers on prevalence, incidence and clinical impact

Even though most clinical data on cachexia have been reported from Western countries, cachexia may be a growing problem in Asia as well, as the population in this area of the world is considerably larger. Considering the current definitions of obesity and sarcopenia in Japan, which are different from the ones in Western countries, the lack of a distinct cachexia definition in Japan is strinking. Only one epidemiological study has reported the prevalence of cachexia using weight loss as part of the definition in patients with stage III or IV non-small cell lung cancer. Although the reported prevalence of 45.6% is within the range of that in Western countries (28-57% in advanced cancer), we cannot compare the prevalence of cachexia in other types of cancer, heart failure, chronic obstructive pulmonary disease (COPD), and kidney disease (CKD) between Japan and Western countries. In patients with heart failure, one third of Japanese patients has a body mass index <20.3 kg/m² whereas the prevalence of underweight is 13.6% in reports from Western countries. These results may suggest that there are more cachectic heart failure patients in Japan, or that using the same definition like Western countries leads to gross overestimation of the prevalence of cachexia in Japan. The rate of underweight patients in COPD has been reported as 31-41% in COPD and seems to be high in comparison to the prevalence of cachexia in Western countries (27-35%). The reported lowest quartile value of BMI (19.6 kg/m²) in CKD may match with the prevalence of cachexia in Western countries (30-60%). The number of clinical trials targeting cachexia is very limited in Japan so far.

Validated determination method of tramadol and its desmethylates in human plasma using an isocratic LC-MS/MS and its clinical application to patients with cancer pain or non-cancer pain

Background

This study aimed to develop a simultaneous determination method for tramadol and its desmethylates in human plasma using isocratic liquid chromatography coupled to tandem mass spectrometry and to validate it for pharmacokinetic evaluation in patients with cancer pain or non-cancer pain.

Methods

The pretreatments for human plasma involved protein precipitation using acetonitrile and methanol under basic conditions. Tramadol, O-desmethylate, N-desmethylate, and N,O-didesmethylate were separated on an octadecylsilyl column filled with 3-μm particles using isocratic mixture of methanol and 0.15 % formic acid in water (35:65, v/v). The mass spectrometer was run in positive ion multiple reaction monitoring mode. This method was applied to the determination of plasma samples in patients treated with oral tramadol.

Results

The chromatographic total run time was 10 min. The calibration curves in human plasma of tramadol, O-desmethylate, N-desmethylate, and N,O-didesmethylate were linear over the concentration ranges of 12.5–1600, 2.5–320, 2.5–320, and 2.5–320 ng/mL, respectively. The lower limits of quantitation of tramadol and its desmethylates in human plasma were 12.5 and 2.5 ng/mL. Their extraction recoveries were 85.5–106.3 %. The intra-day and inter-day precisions and accuracies were 1.6–10.2 % and 89.2–106.2 % for all analytes. The plasma concentration ranges of tramadol, O-desmethylate, N-desmethylate, and N,O-didesmethylate were 18.2–564, 11.8–137, 4.9–250, and 6.1–147 ng/mL in cancer patients, and 32.8–670, 7.0–84.8, 5.1–317, and 6.7–85.2 ng/mL, respectively, in non-cancer patients.

Conclusions

The present method with acceptable analytical performance can be helpful for evaluating the pharmacokinetics of oral tramadol, including the determination of its desmethylates, for patients with cancer pain or non-cancer pain in clinical settings.

Pharmacokinetic considerations and recommendations in palliative care, with focus on morphine, midazolam and haloperidol

INTRODUCTION

A variety of medications are used for symptom control in palliative care, such as morphine, midazolam and haloperidol. The pharmacokinetics of these drugs may be altered in these patients as a result of physiological changes that occur at the end stage of life.

AREAS COVERED

This review gives an overview of how the pharmacokinetics in terminally ill patients may differ from the average population and discusses the effect of terminal illness on each of the four pharmacokinetic processes absorption, distribution, metabolism, and elimination. Specific considerations are also given for three commonly prescribed drugs in palliative care: morphine, midazolam and haloperidol).

EXPERT OPINION

The pharmacokinetics of drugs in terminally ill patients can be complex and limited evidence exists on guided drug use in this population. To improve the quality of life of these patients, more knowledge and more pharmacokinetic/pharmacodynamics studies in terminally ill patients are needed to develop individualised dosing guidelines. Until then knowledge of pharmacokinetics and the physiological changes that occur in the final days of life can provide a base for dosing adjustments that will improve the quality of life of terminally ill patients. As the interaction of drugs with the physiology of dying is complex, pharmacological treatment is probably best assessed in a multi-disciplinary setting and the advice of a pharmacist, or clinical pharmacologist, is highly recommended.

Pharmacokinetics of drugs in cachectic patients: a systematic review

Cachexia is a weight-loss process caused by an underlying chronic disease such as cancer, chronic heart failure, chronic obstructive pulmonary disease, or rheumatoid arthritis. It leads to changes in body structure and function that may influence the pharmacokinetics of drugs. Changes in gut function and decreased subcutaneous tissue may influence the absorption of orally and transdermally applied drugs. Altered body composition and plasma protein concentration may affect drug distribution. Changes in the expression and function of metabolic enzymes could influence the metabolism of drugs, and their renal excretion could be affected by possible reduction in kidney function. Because no general guidelines exist for drug dose adjustments in cachectic patients, we conducted a systematic search to identify articles that investigated the pharmacokinetics of drugs in cachectic patients.

Cancer cachexia raises the plasma concentration of oxymorphone through the reduction of CYP3A but not CYP2D6 in oxycodone-treated patients

This study evaluated the plasma concentrations of oxycodone and its demethylates and opioid-induced adverse effects based on cachexia stage in cancer patients receiving oxycodone. Seventy patients receiving oxycodone for cancer pain were enrolled. Cachexia was evaluated using the Glasgow Prognostic Score (GPS). Predose plasma concentrations of oxycodone, oxymorphone, and noroxycodone were determined at the titration dose. Opioid-induced adverse effects were monitored for 2 weeks after the titration. Plasma concentrations of oxycodone and oxymorphone but not noroxycodone in patients with a GPS of 2 were significantly higher than that with a GPS of 0. The metabolic ratios of noroxycodone but not oxymorphone to oxycodone in patients with a GPS of 1 and 2 were significantly lower than in those with a GPS of 0. A higher GPS was associated with a higher incidence of somnolence, while the GPS did not affect the incidence of vomiting. Plasma concentrations of oxycodone and oxymorphone were not associated with the incidence of adverse effects. In conclusion, cancer cachexia raised the plasma exposures of oxycodone and oxymorphone through the reduction of CYP3A but not CYP2D6. Although the cachexia elevated the incidence of somnolence, alterations in their pharmacokinetics were not associated with the incidence.

The systemic inflammation-based Glasgow Prognostic Score: a decade of experience in patients with cancer

Since the initial work, a decade ago that the combination of C-reactive protein and albumin, the Glasgow Prognostic Score (GPS), had independent prognostic value in patients with cancer, there have been more than 60 studies (>30,000 patients) that have examined and validated the use of the GPS or the modified GPS (mGPS) in a variety of cancer scenarios. The present review provides a concise overview of these studies and comments on the current and future clinical utility of this simple objective systemic inflammation-based score. The GPS/mGPS had independent prognostic value in (a) unselected cohorts (4 studies, >19,400 patients) (b) operable disease (28 studies, >8,000 patients) (c) chemo/radiotherapy (11 studies, >1500 patients) (d) inoperable disease (11 studies, >2,000 patients). Association studies (15 studies, >2,000 patients) pointed to an increased GPS/mGPS being associated with increased weight and muscle loss, poor performance status, increased comorbidity, increased pro-inflammatory and angiogenic cytokines and complications on treatment. These studies have originated from 13 different countries, in particular the UK and Japan. A chronic systemic inflammatory response, as evidenced by the GPS/mGPS, is clearly implicated in the prognosis of patients with cancer in a variety of clinical scenarios. The GPS/mGPS is the most extensively validated of the systemic inflammation-based prognostic scores and therefore may be used in the routine clinical assessment of patients with cancer. It not only identifies patients at risk but also provides a well defined therapeutic target for future clinical trials. It remains to be determined whether the GPS has prognostic value in other disease states.