Comparison of Analgesic Efficacy and Safety of Low-Dose Transdermal Fentanyl and Oral Oxycodone in Opioid-Naïve Patients with Cancer Pain.

In Japan, a low-dose transdermal fentanyl (TDF; 0.5 mg) has been approved to address pain in opioid-naïve patients with cancer; however, efficacy and safety data are lacking. To determine the efficacy and safety of TDF, patients with opioid-naïve cancer pain prescribed TDF (0.5 mg/d) and oral oxycodone sustained-release formulation (OXY) 10 mg/d were extracted from electronic medical and nursing records. Overall, 40 and 101 subjects were analyzed in the TDF and OXY groups, respectively. Compared with baseline (median [minimum, maximum]) values, changes in the Numerical Rating Scale (NRS) score on days 1, 3, and 7 post-administration were as follows: TDF (0 [-5, 4]) and OXY (-1.0 [-8, 3]); TDF (-1.5 [-6, 3]) and OXY (-2.0 [-8, 4]); and TDF (-2.0[-6, 3]) and OXY (-3.0[-8, 5]), respectively. No significant difference was observed between the groups on days 1 and 3; however, the change in the NRS on day 7 was significantly higher in the OXY group than that in the TDF group. Regarding adverse events, nausea occurred in 12.5 and 13.9% of patients in the TDF and OXY groups, respectively, while 12.5% of TDF- and 10.9% of OXY-treated patients experienced somnolence, revealing similar occurrence in both groups. However, constipation was more common in the OXY group (TDF: 50.0%, OXY: 71.3%). No serious adverse events (e.g., respiratory depression) were observed in either group. Low-dose TDF (0.5 mg), available only in Japan, showed comparable efficacy and safety to OXY (10 mg/d) and can be a first choice for opioid-naïve patients with cancer pain.

Low concentrations of clarithromycin upregulate cellular antioxidant enzymes and phosphorylation of extracellular signal-regulated kinase in human small airway epithelial cells.

BACKGROUND: It is well known that low-dose, long-term macrolide therapy is effective against chronic inflammatory airway diseases. Oxidative stress is considered to be a key pathogenesis factor in those diseases. However, the mechanism of action of low-dose, long-term macrolide therapy remains unclear. We have reported that clarithromycin (CAM), which is a representative macrolide antibiotic, could inhibit hydrogen peroxide (H2O2)-induced reduction of the glutathione (GSH)/glutathione disulfide (GSSG) ratio in human small airway epithelial cells (SAECs), via the maintenance of GSH levels through an effect on γ-glutamylcysteine synthetase (γ-GCS) expression. In this study, we examined the influence of CAM against H2O2-induced activities of cellular antioxidant enzymes and phosphorylated extracellular signal regulatory kinase (p-ERK) using SAECs, the main cells involved in chronic airway inflammatory diseases. METHODS: SAECs were pretreated with CAM (1, 5, and 10 µM) for 72 h, and subsequently exposed to H2O2 (100 µM) for 0.5-2 h. Levels of GSH and GSSG, and activities of glutathione peroxidase (GPx)-1, glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), heme oxygenase (HO)-1 and p-ERK were assayed. mRNA expressions of GPx-1 and HO-1 were measured using the real-time reverse transcription polymerase chain reaction (RT-PCR). Tukey's multiple comparison test was used for analysis of statistical significance. RESULTS: Pretreatment with low-dose (1 and 5 µM) CAM for 72 h inhibited H2O2-induced reductions of GPx-1, GR, SOD, CAT and HO-1 activities, and mRNA expressions of GPx-1 and HO-1, and improved the GSH/GSSG ratio. However, these alterations were not observed after pretreatment with high-dose (10 µM) CAM, which suppressed phosphorylation of cell proliferation-associated ERK to cause a significant (p < 0.01) decrease in cell viability. CONCLUSIONS: CAM is efficacious against deterioration of cellular antioxidant enzyme activity caused by oxidative stress under low-dose, long-term treatment conditions. On the other hand, pretreatment with high-dose CAM suppressed phosphorylation of cell proliferation-associated ERK and decreased cell viability. The present study may provide additional evidence as to why low-dose, long-term administration of macrolides is effective for treating chronic inflammatory airway diseases.

Long-term treatment of clarithromycin at a low concentration improves hydrogen peroxide-induced oxidant/antioxidant imbalance in human small airway epithelial cells by increasing Nrf2 mRNA expression.

BACKGROUND: Clarithromycin (CAM), a representative macrolide antibiotic, has been used widely at low doses for long-term therapy of chronic inflammatory airway diseases. Anti-inflammatory effects of macrolide antibiotics were first discovered in clinical practice. Although oxidative stress is known as a key pathogenesis factor in chronic airway inflammatory diseases, the mechanism of action of low-dose, long-term CAM therapy remains unclear. We aimed to examine the cytoprotective action of CAM against hydrogen peroxide (H2O2)-induced cell dysfunction, focusing on CAM dose and treatment duration, and using human small airway epithelial cells (SAECs), the main cells involved in chronic airway inflammatory diseases. METHODS: SAECs were pretreated with CAM (1, 5 or 10 µM) for 24, 48 or 72 h, and were subsequently exposed to H2O2 for 0.5-4 h. Levels of interleukin (IL)-8, glutathione (GSH) and glutathione disulfide (GSSG), and the activities of nuclear factor (NF)-κB and γ-glutamylcysteine synthetase (γ-GCS) were assayed using specific methods. IL-8 mRNA and NF erythroid 2-related factor 2 (Nrf2) mRNA expression were measured using real-time reverse transcription polymerase chain reaction (RT-PCR). Tukey's multiple comparison test was used for analysis of statistical significance. RESULTS: Pretreatment with low-dose (1 or 5 µM), long-term (72 h) CAM inhibited H2O2-induced IL-8 levels, NF-κB activity, and IL-8 mRNA expression, and improved the GSH/GSSG ratio via the maintenance of γ-GCS expression levels. Similar to its enhancing effect on the GSH/GSSG ratio, pretreatment with low-dose CAM for 72 h significantly increased Nrf2 mRNA expression (p < 0.01 and p < 0.05). In contrast, these alterations were not observed after pretreatment with high-dose (10 µM) or short-term (24 and 48 h) CAM. CONCLUSIONS: CAM is efficacious against cell dysfunction caused by oxidative stress under low-dose, long-term treatment conditions. This effect depended on the suppression of NF-κB activation and improvement of the H2O2-induced oxidant/antioxidant imbalance that is achieved by increasing Nrf2 mRNA expression in SAECs. The present study may provide the first evidence of why low-dose, long-term administration of macrolides is effective for treating chronic inflammatory airway diseases.