• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4077-4082
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• 2013

The purpose of this descriptive and comparative study was to examine gender differences relevant to pain intensity, opioid prescription patterns and opioid consumption in Taiwanese oncology outpatients. The 92 participants had been prescribed opioid analgesics for cancer-related pain at least once in the past week and were asked to complete the Brief Pain Inventory - Chinese questionnaire and to recall the dosage of each opioid analgesic that they had ingested within the previous 24 hours. For opioid prescriptions and consumption, all analgesics were converted to morphine equivalents. The results revealed a significant difference between males and female minimum pain thresholds (t = 2.38, p = 0.02) and current pain thresholds (t = 2.12, p = 0.04), with males reporting a higher intensity of pain than females. In addition, this study found that males tended to use prescribed opioid analgesics more frequently than females on the bases of both around the clock (ATC) (t = 1.90, p = 0.06) and ATC plus as needed (ATC + PRN) (t = 2.33, p = 0.02). However, there was no difference between males and females in opioid prescriptions on an ATC basis (t = 0.52, p = 0.60) or at an ATC + PRN basis (t = 0.40, p = 0.69). The results suggest that there may be a gender bias in the treatment of cancer pain, supporting the proposal of routine examination of the effect of gender on cancer pain management. These findings suggest that clinicians should be particularly aware of potential gender differences during pain monitoring and the consumption of prescribed opioid analgesics.

• The Korean Journal of Pain
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• v.33 no.3
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• pp.234-244
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• 2020

Background: Chronic pain affects approximately 22% of the world's population. Opioids can be useful in chronic pain management. However, some patients have negative perception of opioids. The purpose of this research was to evaluate patients' perception about opioids and investigate problems associated with prescribing and taking opioids in South Korea. Methods: Patients who visited a pain clinic in 14 university hospitals of South Korea from September through October 2018 were asked to complete anonymous questionnaires about taking opioids. Results: Of the 368 patients that were surveyed (female 53.3%, male 46.7%), 56.8% were prescribed opioids. In the opioid group, 92.8% patients had heard of opioids from their doctor and 72.6% of them had a positive perception about opioids. The side effects associated with opioid use were constipation (35.4%), dizziness (24.6%), nausea and vomiting (17.4%), dysuria (6.2%), and addiction (2.0%). In the no opioid group, the primary sources of information about opioids were doctors (49.2%), mass media (30.8%), and the internet (16.2%). The main reasons why 39.0% patients did not take opioids were fear of addiction (57.7%) and side effects (38.5%). There were 71.5% and 60.9% patients in the opioid and no opioid group, respectively, who wished to take opioids when their numeric rating scale pain score was ≥ 7. Conclusions: Perception of opioids among patients who take them was either neutral or positive. However, 39.0% patients who have not been prescribed opioids did not want an opioid prescription, citing fear of addiction and side effects as the primary reasons.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.153-165
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• 1994

In this study, we tested the influences of several ${\kappa}$ opioid ligands on the $[^3H]diprenorphine$ binding in rat and guinea pig cortex membrane preparations. Using paradigm to block ${\mu}\;and\;{\delta}$ opioid receptors with $DAMGO(1{\mu}M)$ and $DPDPE(1{\mu}M)$, $[^3H]diprenorphine$ labeled ${\kappa}$ sites. Competition analysis in both rat and guinea pig cortex has shown a single population of $[^3H]diprenorphine$ binding site with different Kd values, respectively. There is a significant difference in Ki values of (-) WIN44441 and (+)WIN44441 in both rat and guinea pig cortex. Bremazocine, (-)ethylketocyclazocine, (-)cyclazocine, nor-binaltorphimine effectively inhibited the $[^3H]diprenorphine$ binding with different Ki values in rat and guinea pig cortex. U-69,593, U-50,488H and dynorphine-A (1-8) did not inhibit the $[^3H]diprenorphine$ binding in rat but in guinea pig cortex. Nor-binaltorphimine was a ligand discriminate the ${\kappa}_1$, and ${\kappa}_2$ receptor most effectively. We, also, examined the influence of Na ion and $GTP{\gamma}S$, a nonhydrolyzable guanine nucleotide analog, on the inhibition of $[^3H]diprenorphine$ binding by diprenorphine, (-)ethyl-ketocyclazocine, U-69,593 and bremazocine. By the replacement of NaCl with N-methy-D-glucamine or addition of $GTP{\gamma}S$, Ki values of diprenorpnine were not changed and that of ethylketocyclazocine were changed significantly in both rat and guinea pig cortex. The Ki value of bremazocine was decreased by removal of Na ion, and increased by $GTP{\gamma}S$, however, was not changed by any one of either. These results suggest that there are 2 kinds of subtypes of ${\kappa}$ opioid receptor, ${\kappa}_1$, and ${\kappa}_2$, showing different Ki values for various ${\kappa}$ opioid ligands, also, bremazocine possess the antagonistic property at ${\kappa}_2$ site which is dominant subtype of K receptor in rat cortex.

• Journal of Hospice and Palliative Care
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• v.20 no.2
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• pp.131-135
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• 2017

Purpose: Oral naloxone is combined with oxycodone to alleviate or prevent opioid-induced constipation in cancer pain patients. However, there is still concern that oral naloxone may precipitate opioid withdrawal symptoms in patients on opioids. We retrospectively investigated clinical characteristics of cancer patients who experienced opioid withdrawal symptoms. Methods: We reviewed medical records of all patients who were prescribed with oral oxycodone/naloxone at a tertiary cancer center from January 1, 2012 through December 31, 2016. Eligible patients were screened based on demographics, opioid and naloxone dosages, clinical manifestation and pain intensity. Results: Among a total of 1,641 patients, 10 patients were selected. Seven patients were male, and the average age was 68.1 years. The median dose of naloxone that induced withdrawal symptoms was 20 mg. Most common withdrawal symptom was shivering (seven patients) followed by cold sweating (five), and muscle twitching (five). Other symptoms included restlessness, fever, dizziness, and yawning. Pain was exacerbated from the median intensity of numeric rating scale (NRS) 3 to NRS 6. Conclusion: Opioid withdrawal symptoms may occur when switching to oral oxycodone/naloxone for cancer patients who have been treated with other strong opioids. A prospective, multicenter study on this issue should be conducted in future.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.187-191
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• 2006

Background: Patient-controlled epidural analgesia (PCEA), using a local anesthetic-opioid mixture, has been effectively applied after total knee replacement (TKR) surgery, which is associated with intense postoperative pain that requires postoperative analgesia for both rehabilitation and the pain itself. However, adverse opioid-related effects, such as nausea, vomiting and pruritus, are commonly encountered. It was our hypothesis that the adverse opioid-related effects could be reduced by the addition of naloxone, an opioid antagonist, to a mixture of fentanyl-ropivacaine PCEA. Methods: In 120 patients undergoing elective TKR surgery, epidural or combined spinal-epidural (CSE) anesthesia was performed and PCEA applied. In the control group (n = 65), 0.16% ropivacaine and $3{\mu}g/ml$ fentanyl ($2.4{\mu}g/ml$ for those older than 65 yrs) were administered. In the naloxone group (n = 55), naloxone ($2{\mu}g/ml$) was coadministered with the above regimen. The incidence and severity of postoperative nausea and vomiting, and the frequency of pruritus, the visual analog score (VAS) and the PCEA volume used were assessed 6 and 24 hrs after surgery. Results: The incidence of nausea and vomiting during the early postoperative period, and those of pruritus during the late postoperative period were significantly lower in the naloxone group. The VAS pain scores, the PCEA volume used and amount of rescue IV meperidine were similar in the two groups. Conclusions: A small dose of naloxone mixed with an opioid significantly reduces the incidence and severity of adverse opioid-related effects in PCEA, without reducing the analgesic effect.

• The Korean Journal of Pain
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• v.35 no.4
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• pp.475-487
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• 2022

Background: Use of opioids for chronic intractable pain is increasing globally, and their proper use can improve patients' quality of life. In contrast, opioid use disorders, such as abuse or addiction, caused by prescribing opioids, are a worldwide issue. This study aimed to understand current opioid prescribing patterns and pain physicians' experiences with opioid use in South Korea. Methods: Pain physicians in 42 university hospitals in South Korea were asked to complete anonymous questionnaires regarding opioid prescriptions. Results: A total of 69 surveys were completed. Most pain physicians started prescribing opioids at a pain score of 7/10 and aimed to reduce pain by 50%. Most physicians (73.1%) actively explained the prescribed medications and possible side effects, and 61.2% of physicians preferred the prescription interval of 4 weeks. Immediate-release opioids were the most popular treatment for breakthrough pain (92.6%). The most common side effect encountered by physicians was constipation (43.3%), followed by nausea/vomiting (34.3%). Of the physicians, 56.5% replied that addiction and misuse prevalences were less than 5%. However, the most concerning side effect was addiction (33.0%). Conclusions: The survey results showed that the prescribing patterns of pain physicians generally followed Korean guidelines. Physicians were most interested in the safety and effectiveness of opioid prescriptions. They were most concerned about respiratory depression and abuse or addiction. A significant number of physicians agreed that the NHIS regulations needed improvement for patient convenience and safe and effective treatment, though there were pros and cons of the NHIS restrictions on prescription conditions.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.374-379
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• 1996

Background: Recently, improvements in drug administration technology have intensified interest in the treatment of postoperative pain. this has resulted in increased use of continuous intravenous infusion of opioid and epidural opioid as alternative to traditional intramuscular administration of opioid. The goal of this study, therefore, was to document the effects of pain control and side effects following continuous intravenous infusion of morphine or meperidine and intramuscular meperidine following cesarean section. Methods: The vital signs, pain score, oxygen saturation and side effects were compared in 150 patients receiving continuous intravenous infusion of morphine, 30 ${\mu}g/kg/hr$ (n=50, group 1); continuous intravenous infusion of meperidine, 150 ${\mu}g/kg/hr$ (n=50, group 2); or intramuscular meperidine, 50mg/every 6hrs (n=50, group 3). Results: VAS (Visual Analogue Scale) was significantly decreased after 30 minutes of administration in all three groups and was significantly lower at 1 hour, but higher at 6 hours in group 3 than two other groups. Severe desaturation episode, defined as $SpO_2$<90%, occurred in the group 3(0.2%). Moderate desaturation episodes, defined as $SpO_2$ 91~95%, occurred more in group 3 than in group 1 and 2 (17.4% vs. 10.4%, 8.2%). The incidence of side effects were similar among three groups. Conclusion: The continuous infusion of opioid was more effective and safe method of postoperative pain control than traditional intramuscular injection.

• International Journal of Oral Biology
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• v.34 no.3
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• pp.137-142
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• 2009

Whole-body $\gamma$-irradiation(WBI), which produces an oxidative stress, is reported to attenuate the acute antinociceptive action of morphine (a $\mu$-opioid receptor agonist), but not DPLPE (a $\delta$-opioid receptor agonist), in mice. Recently, we also reported that antinociceptive effect of morphine, but not $\beta$-endorphin (a novel $\varepsilon$-opioid receptor agonist), was attenuated by oxidative stress. These findings prompted us to investigate the effect of WBI on the antinociception of morphine and $\beta$-endorphin in mice. Mice were exposed to WBI (5 Gy) from a $^{60}Co$ gamma-source and tested 2 hours later for antinociception produced by intracerebroventricular administration of morphine or $\beta$-endorphin using the hot water tail-immersion and the writhing tests. WBI significantly attenuated the antinociception produced by morphine only in the hot water tail-immersion test, whereas the antinociception of $\beta$-endorphin was significantly potentiated by WBI in both tests. These results demonstrate a differential sensitivity of $\mu$- and $\varepsilon$-opioid receptors to WBI, and support the hypothesis that morphine and $\beta$-endorphin administered supraspinally produce antinociception by different neuronal mechanisms.

• The Korean Journal of Pain
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• v.27 no.3
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• pp.200-209
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• 2014

Background: Spinal opioid administration is an excellent option to separate the desirable analgesic effects of opioids from their expected dose-limiting side effects to improve postoperative analgesia. Therefore, physicians must better identify either specific opioids or adequate doses and routes of administration that result in a mainly spinal site of action rather than a cerebral analgesic one. Methods: The purpose of this topical review is to describe current available clinical evidence to determine what opioids reach high enough concentrations to produce spinally selective analgesia when given by epidural or intrathecal routes and also to make recommendations regarding their rational and safety use for the best management of postoperative pain. To this end, a search of Medline/Embase was conducted to identify all articles published up to December 2013 on this topic. Results: Recent advances in spinal opioid bioavailability, based on both animals and humans trials support the theory that spinal opioid bioavailability is inversely proportional to the drug lipid solubility, which is higher in hydrophilic opioids like morphine, diamorphine and hydromorphone than lipophilic ones like alfentanil, fentanyl and sufentanil. Conclusions: Results obtained from meta-analyses of RTCs is considered to be the 'highest' level and support their use. However, it's a fact that meta-analyses based on studies about treatment of postoperative pain should explore clinical surgery heterogeneity to improve patient's outcome. This observation forces physicians to use of a specific procedure surgical-based practical guideline. A vigilance protocol is also needed to achieve a good postoperative analgesia in terms of efficacy and security.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.22-28
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• 1993

This study was undertaken to determine the effects of ginseng total saponin (GTS) on stress- induced analgesia (SIA) in mice. intermittent foot shock (FS)-SIA was antagonized not by on but by naloxone in the tail flick FS-SIA which was not antagonized by naloxone in the T.F. test. On the other hand, GTS did not antagonize the continuous FS-SIA naloxone antagonized in the T.P. test. Also GTS antagonized psychological (PSIF)-SIA which was not antagonized by naloxone in the T.F. test. However, GTS did not antagonize the PSY-SIA which naloxone antagonized in the T.P. test. Forced swimming (FSIP)-SIA was not affected by both GTS and naloxone. These results suggest that the antapeonisms of intermittent FS-SIA in the T.F. test, continuous FS-SIA and PSY-SIA by GTS are mediated by non-opioid mechanisms but the antagonism of intermittent FS-SIA in the T.P. test by GTS is mediated by opioid mechanism.