Opioid-induced or pain relief-reduced symptoms in advanced cancer patients?

BACKGROUND: While opioids in increasing doses may produce adverse effects, the same adverse effects may be associated with poor pain control. Moreover, in the clinical setting symptomatic treatment and illness may balance the outcome of opioid titration. Some adverse effects may tend to disappear continuing the treatment in a long-term period. AIMS: The aim of this study was to monitor the effects of a rapid opioid titration combined with symptomatic treatment in patients with poor relief and to monitor these changes in the following period of 20 days. METHODS: A consecutive sample of 35 patients admitted to an acute Pain Relief and Palliative Care Unit were titrated with opioids, according to a department policy, allowing administration of parenteral opioids to assist opioid titration with oral or transdermal opioids. RESULTS: Thirty-three patients were followed up for the period of the study. Pain was adequately controlled and doses were opioid doses were stable after a mean of 40 h. Opioid escalation index (OEI) was extremely high initially, and then progressively declined at the following study intervals. Weakness and nausea and vomiting did not change, as well as confusion and appetite. Drowsiness, constipation and dry mouth significantly increased and then did not change, although a significant decrease in drowsiness was subsequently observed. Well-being improved some weeks after opioid stabilization. In multivariate analysis, drowsiness and dry mouth were correlated to opioid doses. CONCLUSION: The effects reported were often due to multiple causes. A rapid decrease in pain intensity induced by rapid opioid titration does not produce changes in weakness, nausea and vomiting, appetite. While constipation appears the most relevant problem, resistant to common symptomatic treatment, drowsiness initially produced by acute opioid dose increase and the achievement of pain relief, tends to spontaneously decrease, probably as the result of late tolerance. Improved well-being may be the late positive effect of pain relief, also influenced by the setting of home care.     

Breakthrough pain characteristics and syndromes in patients with cancer pain. An international survey

Breakthrough pain (BKP) is a transitory flare of pain that occurs on a background of relatively well controlled baseline pain. Previous surveys have found that BKP is highly prevalent among patients with cancer pain and predicts more severe pain, pain-related distress and functional impairment, and relatively poor quality of life. An international group of investigators assembled by a task force of the International Association for the Study of Pain (IASP) evaluated the prevalence and characteristics of BKP as part of a prospective, cross-sectional survey of cancer pain. Fifty-eight clinicians in 24 countries evaluated a total of 1095 patients with cancer pain using patient-rated items from the Brief Pain Inventory (BPI) and observer-rated measures. The observer-rated information included demographic and tumor-related data, the occurrence of BKP, and responses on checklists of pain syndromes and pathophysiologies. The clinicians reported BKP in 64.8% of patients. Physicians from English-speaking countries were significantly more likely to report BKP than other physicians. BKP was associated with higher pain scores and functional interference on the BPI. Multivariate analysis showed an independent association of BKP with the presence of more than one pain, a vertebral pain syndrome, pain due to plexopathy, and English-speaking country. These data confirm the high prevalence of BKP, its association with more severe pain and functional impairment, and its relationship to specific cancer pain syndromes. Further studies are needed to characterize subtypes of BKP. The uneven distribution of BKP reporting across pain specialists from different countries suggests that more standardized methods for diagnosing BKP are needed.     

Dietary carotenoid lutein protects against DNA damage and alterations of the redox status induced by cisplatin in human derived HepG2 cells

Several epidemiological and experimental studies has been reported that lutein (LT) presents antioxidant properties. Aim of the present study was to investigate the protective effects of LT against oxidative stress and DNA damage induced by cisplatin (cDDP) in a human derived liver cell line (HepG2). Cell viability and DNA-damage was monitored by MTT and comet assays. Moreover, different biochemical parameters related to redox status (glutathione, cytochrome-c and intracellular ROS) were also evaluated. A clear DNA-damage was seen with cDDP (1.0μM) treatment. In combination with the carotenoid, reduction of DNA damage was observed after pre- and simultaneous treatment of the cells, but not when the carotenoid was added to the cells after the exposure to cDDP. Exposure of the cells to cDDP also caused significant changes of all biochemical parameters and in co-treatment of the cells with LT, the carotenoid reverted these alterations. The results indicate that cDDP induces pronounced oxidative stress in HepG2 cells that is related to DNA damage and that the supplementation with the antioxidant LT may protect these adverse effects caused by the exposure of the cells to platinum compound, which can be a good predict for chemoprevention.     

p.R254Q mutation in the aquaporin‐2 water channel causing dominant nephrogenic diabetes insipidus is due to a lack of arginine vasopressin‐induced phosphorylation

Vasopressin regulates human water homeostasis by re‐distributing homotetrameric aquaporin‐2 (AQP2) water channels from intracellular vesicles to the apical membrane of renal principal cells, a process in which phosphorylation of AQP2 at S256 by cAMP‐dependent protein kinase A (PKA) is thought to be essential. Dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin, is caused by AQP2 gene mutations. Here, we investigated a reported patient case of dominant NDI caused by a novel p.R254Q mutation. Expressed in oocytes, AQP2‐p.R254Q appeared to be a functional water channel, but was impaired in its transport to the cell surface to the same degree as AQP2‐p.S256A, which mimics non‐phosphorylated AQP2. In polarized MDCK cells, AQP2‐p.R254Q was retained and was distributed similarly to that of unstimulated wt‐AQP2 or AQP2‐p.S256A. Upon co‐expression, AQP2‐p.R254Q interacted with, and retained wt‐AQP2 in intracellular vesicles. In contrast to wild‐type AQP2, forskolin did not increase AQP2‐p.R254Q phosphorylation at S256 or its translocation to the apical membrane. Mimicking constitutive phosphorylation in AQP2‐p.R254Q with the p.S256D mutation, however, rescued its apical membrane expression. These date indicate that a lack of S256 phosphorylation is the sole cause of dominant NDI here, and thereby, p.R254Q is a loss of function instead of a gain of function mutation in dominant NDI. © 2009 Wiley‐Liss, Inc.     

Relative contribution of ecto-ATPase and ecto-ATPDase pathways to the biphasic effect of ATP on acetylcholine release from myenteric motoneurons

Background and purpose:

The relative contribution of distinct ecto-nucleotidases to the modulation of purinergic signalling may depend on differential tissue distribution and substrate preference.

Experimental approach:

Extracellular ATP catabolism (assessed by high-performance liquid chromatography) and its influence on [³H]acetylcholine ([³H]ACh) release were investigated in the myenteric plexus of rat ileum in vitro.

Key results:

ATP was primarily metabolized via ecto-ATPDase (adenosine 5′-triphosphate diphosphohydrolase) into AMP, which was then dephosphorylated into adenosine by ecto-5′-nucleotidase. Alternative conversion of ATP into ADP by ecto-ATPase (adenosine 5′-triphosphatase) was more relevant at high ATP concentrations. ATP transiently increased basal [³H]ACh outflow in a 2′,3′-O-(2,4,6-trinitrophenyl)adenosine-5′-triphosphate (TNP-ATP)-dependent, tetrodotoxin-independent manner. ATP and ATPγS (adenosine 5′-[γ-thio]triphosphate), but not α,β-methyleneATP, decreased [³H]ACh release induced by electrical stimulation. ADP and ADPβS (adenosine 5′[β-thio]diphosphate) only decreased evoked [³H]ACh release. Inhibition by ADPβS was prevented by MRS 2179 (2′-deoxy-N⁶-methyl adenosine 3′,5′-diphosphate diammonium salt, a selective P2Y₁ antagonist); blockade of ADP inhibition required co-application of MRS 2179 plus adenosine deaminase (which inactivates endogenous adenosine). Blockade of adenosine A₁ receptors with 1,3-dipropyl-8-cyclopentyl xanthine enhanced ADPβS inhibition, indicating that P2Y₁ stimulation is cut short by tonic adenosine A₁ receptor activation. MRS 2179 facilitated evoked [³H]ACh release, an effect reversed by the ecto-ATPase inhibitor, {"type":"entrez-protein","attrs":{"text":"ARL67156","term_id":"1186396857","term_text":"ARL67156"}}ARL67156, which delayed ATP conversion into ADP without affecting adenosine levels.

Conclusions and implications:

ATP transiently facilitated [³H]ACh release from non-stimulated nerve terminals via prejunctional P2X (probably P2X₂) receptors. Hydrolysis of ATP directly into AMP by ecto-ATPDase and subsequent formation of adenosine by ecto-5′-nucleotidase reduced [³H]ACh release via inhibitory adenosine A₁ receptors. Stimulation of inhibitory P2Y₁ receptors by ADP generated alternatively via ecto-ATPase might be relevant in restraining ACh exocytosis when ATP saturates ecto-ATPDase activity.     

Intravenous morphine for breakthrough (episodic-) pain in an acute palliative care unit: a confirmatory study

The aim of this prospective cohort study was to confirm the safety of intravenous morphine (IV-M) used in doses proportional to the basal opioid regimen for the management of breakthrough pain and to record the nurse compliance on regularly recording data regarding breakthrough pain treated by IV-M. Over a one-year period, 99 patients received IV-M for breakthrough pain during 116 admissions. The IV-M dose was 1/5 of the oral daily dose, converted using an equianalgesic ratio of 1/3 (IV/oral). For each episode, nurses were instructed to routinely collect changes in pain intensity and emerging problems when pain became severe (T0), and to reassess the patient 15minutes after IV-M injection (T15). Nurses were unaware of the aim of the study and just followed department policy. In total, 945 breakthrough events treated by IV-M were recorded and the mean number of events per patient per admission was eight (95% confidence interval (CI) 6.9-9.5). The mean dose of IV-M was 12mg (95% CI 9-14mg). In the 469 events (49.6%) with a complete assessment, a decrease in pain of more than 33% and 50% was observed in 287 (61.2%) and 115 (24.5%) breakthrough events, respectively. The mean pain intensity decreased from 7.2 (T0) to 2.7 (T15). In eight episodes, no changes in pain intensity were observed and a further dose of IV-M was given. The remaining patients did not require further interventions. No clinical events requiring medical intervention were recorded. In this confirmatory study, IV-M was administered for the management of breakthrough pain in doses proportional to the basal opioid regimen to all patients, including older patients and those requiring relatively large doses. This did not result in life-threatening adverse effects in a large number of patients and was effective in most cases. The role of nurses is of paramount importance in monitoring and collecting data and gathering information for audit purposes on the unit.     

Clinical and financial analysis of an acute palliative care unit in an oncological department

The aim of this article is to describe the clinical activity and medical intervention of an acute model of palliative care unit (APC), as well as the reimbursement procedures and economic viability. A sample of 504 patients admitted at an APC in 1 year was surveyed. Indications for admission, pain and symptom intensity, analgesic treatments, procedures, instrumental examinations and modalities of discharge were recorded. For each patient, tariff for reimbursement was calculated according to the existent disease related grouping (DRG) system. The mean age was 62 years, and 246 patients were males. The mean hospital stay was 5.4 days. Pain control was the most frequent indication for admission. All patients had laboratory tests and several instrumental examinations. Almost all patients were prescribed one or more opioids at significant doses, and different routes of administration, as well as medication as needed. 59 patients received blood cell transfusions and 34 interventional procedures. Only 40 patients died in the unit, 11 of them being sedated at the end of life. Treatment efficacy was considered optimal and mild in 264 and 226 patients respectively. A mean of 3019 euros for admission was reimbursed by the Health Care System. APCs are of paramount importance within an oncological department, as they provide effective and intensive treatments during the entire course of disease, providing a simultaneous and integrated approach. Our findings also suggest both a cost and quality incentive for oncological departments to develop APC.     

The role of free radicals in endogenous adaptation and intracellular signals

Oxidative stress can generate a mass of oxygen free radicals (OFR) in the cells, and these OFRs can induce several acute and chronic symptoms and diseases. If the amount of the generated OFRs overwhelms the antioxidant capacity of the cells, the pathophysiological changes may lead to the death of the cell or the development of chronic degenerative diseases.