Pentazocine, a Kappa-Opioid Agonist, Is Better Than Diclofenac for Analgesia in Acute Pancreatitis: A Randomized Controlled Trial.

OBJECTIVES: The ideal analgesic is not known for patients with acute pancreatitis (AP). Concerns have been raised about serious adverse effects of opioid analgesics increasing the severity of AP. We hypothesized that nonsteroidal anti-inflammatory drugs might be better analgesics because of their anti-inflammatory effect. Our objective was to compare pentazocine, an opioid, and diclofenac, a nonsteroidal anti-inflammatory drug, for adequate analgesia in patients with AP. METHODS: In a double-blind randomized controlled trial, patients with AP were randomized to either intravenous diclofenac 75 mg or pentazocine 30 mg. Fentanyl was given as a rescue analgesic through a patient-controlled analgesia pump. Primary outcome was pain relief measured objectively by the dose of fentanyl required as the rescue analgesic, pain-free period, and numbers of effective and ineffective demands of fentanyl. Secondary outcome was adverse events. RESULTS: Fifty patients were randomized, 24 to the pentazocine group and 26 to the diclofenac group. Baseline characteristics were comparable between the groups. Pentazocine was found to be better than diclofenac in terms of significantly lower dose of the rescue analgesic (fentanyl) required (126 µg (interquartile range (IQR) 65-218 µg) vs 225.5 µg (IQR 133-427 µg); P = 0.028) and longer pain-free period (31.1 ± 8.2 vs 27.9 ± 6.6 hours, P = 0.047). The number of effective and ineffective demands was lower in the pentazocine group compared with the diclofenac group (11.5 (IQR 8-15) vs 16 (IQR 13-20), P = 0.098) although not statistically significant. Adverse events were similar between the groups. CONCLUSIONS: Pentazocine, a kappa-opioid receptor agonist, was significantly better than diclofenac for pain relief in AP (Trial registration number: CTRI/2016/09/007326).

Thiamylal Plus Pentazocine Shows Similar Efficacy as Ketamine Plus Midazolam for Painful Procedures in Children With Leukemia.

This retrospective study compared the use of thiamylal plus pentazocine (TP) to ketamine plus midazolam (KM) in children with leukemia who were undergoing bone marrow aspiration and/or intrathecal chemotherapy. A total of 268 procedures in 35 children with leukemia were retrospectively analyzed for efficacy and adverse events. All procedures were successfully completed without severe adverse events. TP induced significantly faster sedation. The incidents of desaturation were significantly greater in the TP group, but were transient and recovered by oxygen supplementation alone. Therefore, TP can be a useful combination with a similar efficacy as KM for painful procedures in children.

Enhancement of Dissolution and Skin Permeability of Pentazocine by Proniosomes and Niosomal Gel.

Proniosomes (PN) are the dry water-soluble carrier systems that may enhance the oral bioavailability, stability, and topical permeability of therapeutic agents. The low solubility and low oral bioavailability due to extensive first pass metabolism make Pentazocine as an ideal candidate for oral and topical sustained release delivery. The present study was aimed to formulate the PNs by quick slurry method that are converted to niosomes (liquid dispersion) by hydration, and subsequently formulated to semisolid niosomal gel. The PNs were found in spherical shape in the SEM and stable in the physicochemical and thermal analysis (FTIR, TGA, and XRD). The quick slurry method produced high recovery (> 80% yield) and better flow properties (θ = 28.1-37.4°). After hydration, the niosomes exhibited desirable entrapment efficiency (44.45-76.23%), size (4.98-21.3 µm), and zeta potential (- 9.81 to - 21.53 mV). The in vitro drug release (T100%) was extended to more than three half-lives (2-4 h) and showed good fit to Fickian diffusion indicated by Korsmeyer-Peppas model (n = 0.136-0.365 and R2 = 0.9747-0.9954). The permeation of niosomal gel was significantly enhanced across rabbit skin compared to the pure drug-derived gel. Therefore, the PNs are found promising candidates for oral as dissolution enhancement and sustained release for oral and topical delivery of pentazocine for the management of cancer pain.

Prophylactic Pentazocine Reduces the Incidence of Pruritus After Cesarean Delivery Under Spinal Anesthesia With Opioids: A Prospective Randomized Clinical Trial.

BACKGROUND: The incidence of pruritus after cesarean delivery under spinal anesthesia with opioids is high, ranging from 50% to 100%. Pruritus is difficult to prevent; however, pentazocine has been shown to be an effective treatment. Despite this, the prophylactic effect of pentazocine on pruritus has not been defined. This randomized double-blind trial aimed to evaluate the effect of intraoperative IV pentazocine on the incidence of opioid-induced pruritus within the first 24 hours after administration of neuraxial opioids. METHODS: We obtained institutional review board approval and written informed consent from the 122 patients (American Society of Anesthesiologists [ASA] physical status II; aged 20-40 years) scheduled for elective cesarean delivery who were included in this study. Spinal anesthesia was performed with 10 mg of 0.5% hyperbaric bupivacaine, 10 µg of fentanyl, and 100 µg of morphine. After delivery of the baby and placenta, the parturient women were randomized to intravenously receive 15 mg (1 mL) of pentazocine or 1 mL of saline. All women received postoperative analgesia with the epidural infusion of 0.15% levobupivacaine. The presence of pruritus within the first 24 hours after intrathecal administration of opioids was recorded, and severity of itch, numerical rating scale (NRS) for pain, and adverse effects were also recorded at the time of the arrival on the ward, as well as 3, 6, 12, and 24 hours after the intrathecal administration of opioids. RESULTS: A total of 119 women completed the study. IV pentazocine reduced the overall incidence of pruritus within the first 24 hours compared to IV saline, with an estimated relative risk of 69% (95% confidence interval [CI], 52%, 90%; P = .007). IV pentazocine also reduced the severity of pruritus. The incidence of nausea and vomiting was not significantly different. There were no significant differences in postoperative NRS scores. CONCLUSIONS: A single 15-mg dose of IV pentazocine after delivery can reduce both the incidence and severity of pruritus in women who have received subarachnoid opioids during cesarean delivery.

Cohort study of pain symptoms and management following impacted mandibular third molar extraction.

OBJECTIVE: The aim of this study was to investigate the possibility of intravenous sedation as a useful pain-relieving option for impacted third molar extractions. SUBJECTS AND METHODS: A prospective cohort study was conducted among patients who underwent bilateral mandibular third molar extractions under local anaesthesia and intravenous sedation (sedation group) and patients who underwent unilateral mandibular third molar extraction under local anaesthesia alone (local anaesthesia group). The frequency of use of postoperative oral analgesia and the intensity of pain assessed using the full cup test were compared between the two groups. RESULTS: The maximum pain intensity (0-100) on postoperative day 1 in the sedation and local anaesthesia groups was 72.8 ± 16.98 and 84.8 ± 15.84, respectively, and the mean pain intensity was 42.2 ± 16.00 and 49.6 ± 18.94. The maximum and mean pain intensities in the sedation group were significantly milder than those in the local anaesthesia group. The number of oral analgesic doses in the sedation group was significantly smaller on the day of surgery and on postoperative day 1 than in the local anaesthesia group. CONCLUSIONS: The results of this study suggest that bilateral impacted mandibular third molar extractions under intravenous sedation could be a recommended treatment option.

Blockade of Cocaine or σ Receptor Agonist Self Administration by Subtype-Selective σ Receptor Antagonists.

The identification of sigma receptor (σR) subtypes has been based on radioligand binding and, despite progress with σ1R cellular function, less is known about σR subtype functions in vivo. Recent findings that cocaine self administration experience will trigger σR agonist self administration was used in this study to assess the in vivo receptor subtype specificity of the agonists (+)-pentazocine, PRE-084 [2-(4-morpholinethyl) 1-phenylcyclohexanecarboxylate hydrochloride], and 1,3-di-o-tolylguanidine (DTG) and several novel putative σR antagonists. Radioligand binding studies determined in vitro σR selectivity of the novel compounds, which were subsequently studied for self administration and antagonism of cocaine, (+)-pentazocine, PRE-084, or DTG self administration. Across the dose ranges studied, none of the novel compounds were self administered, nor did they alter cocaine self administration. All compounds blocked DTG self administration, with a subset also blocking (+)-pentazocine and PRE-084 self administration. The most selective of the compounds in binding σ1Rs blocked cocaine self administration when combined with a dopamine transport inhibitor, either methylphenidate or nomifensine. These drug combinations did not decrease rates of responding maintained by food reinforcement. In contrast, the most selective of the compounds in binding σ2Rs had no effect on cocaine self administration in combination with either dopamine transport inhibitor. Thus, these results identify subtype-specific in vivo antagonists, and the utility of σR agonist substitution for cocaine self administration as an assay capable of distinguishing σR subtype selectivity in vivo. These results further suggest that effectiveness of dual σR antagonism and dopamine transport inhibition in blocking cocaine self administration is specific for σ1Rs and further support this dual targeting approach to development of cocaine antagonists.

PENTAZOCINE VERSUS PENTAZOCINE WITH RECTAL DICLOFENAC FOR POSTOPERATIVE PAIN RELIEF AFTER CESAREAN SECTION- A DOUBLE BLIND RANDOMIZED PLACEBO CONTROLLED TRIAL IN A LOW RESOURCE AREA.

BACKGROUND: The unimodal approach of using pentazocine as post-cesarean section pain relief is inadequate, hence the need for a safer, easily available and more effective multimodal approach. AIM: To evaluate the effectiveness of rectal diclofenac combined with intramuscular pentazocine for postoperative pain following cesarean section. METHODS: In this double blind clinical trial, 130 pregnant women scheduled for cesarean section under spinal anesthesia were randomly assigned to two groups. Group A received 100mg diclofenac suppository and group B received placebo suppository immediately following surgery, 12 and 24h later. Both groups also received intramuscular pentazocine 30mg immediately following surgery and 6 hourly postoperatively in the first 24 h. Postoperative pain was assessed by visual analogue scale at end of surgery and 2, 12 and 24 h after surgery. Patient satisfaction scores were also assessed. RESULTS: One hundred and sixteen patients completed the study. Combining diclofenac and pentazocine had statistically significant reduction in pain intensity at 2, 12, and 24 hours postoperatively compared to pentazocine alone (p <0.05). No significant side effects were noted in both groups. The combined group also had significantly better patient satisfaction scores. CONCLUSION: The addition of diclofenac suppository to intramuscular pentazocine provides better pain relief after cesarean section and increased patient satisfaction.

Simple minimal sedation for catheter ablation of atrial fibrillation.

BACKGROUND: Deep sedation or general anesthesia is generally used during atrial fibrillation (AF) ablation. The aim of this study was to report the safety and feasibility of minimal sedation during AF ablation. METHODS AND RESULTS: One thousand and fifty-two AF ablation procedures in 819 patients (62 ± 11 years, 621 men, 506 paroxysmal) were included. Boluses of intravenous hydroxyzine pamoate and pentazocine were administered, with a maximal dose of 100 mg of hydroxyzine and 60 mg of pentazocine in response to pain. If the pain was intolerable or patients requested deeper sedation, moderate sedation using dexmedetomidine or propofol was introduced. Among 819 consecutive first procedures, the procedure was completed under minimal sedation in 795 (97.1%) patients without inotropic drugs or respiratory support, whereas in 20 (2.4%) patients, anesthesia was switched to moderate sedation due to pain. Patients requiring a switch to moderate sedation were significantly younger than those without (53.6 ± 2.3 vs. 62.6 ± 10.4, P<0.01). No procedures were abandoned due to adverse effects of sedation. Significant intra-procedural blood pressure decreases requiring inotropic drugs were not observed in any patients. Among 233 patients who underwent repeat procedures, 6 (2.6%) requested moderate sedation before the procedure. The mean procedure time was 151 ± 54 min. Cardiac tamponade, unrelated to sedation, was observed in 7 (0.66%) procedures. CONCLUSIONS: Minimal sedation might be acceptable anesthesia in the vast majority of AF ablation procedures performed in electrophysiological laboratories.

An effective and safe sedation technique combining target-controlled infusion pump with propofol, intravenous pentazocine, and bispectral index monitoring for peroral double-balloon endoscopy.

BACKGROUND/AIMS: Because peroral double-balloon endoscopy (DBE) is a time-consuming, painful procedure, sedation with analgesics, and/or anesthetics is generally required. The aim of this prospective study was to investigate the safety and efficacy of our sedation protocol for peroral DBE, which consisted of target-controlled infusion (TCI) anesthesia with propofol, an intravenous bolus of pentazocine, and bispectral index (BIS) monitoring. METHODS: A total of 34 consecutive patients who underwent DBE by the oral approach were enrolled. Patients were primarily sedated with a continuous infusion of propofol and adjusted in accordance with the BIS levels. The bolus infusion of pentazocine was performed when the propofol infusion was insufficient. The primary outcome measure of this study was to ensure the safety and efficacy of this sedation technique. The secondary purpose was to identify the characteristics of the patient who required the bolus infusion of pentazocine. RESULTS: Five patients (14.7%) required a reduction in the dose of propofol. However, no patient experienced any serious adverse events. All patients (100%) and 80.6% (25/31) of endoscopists answered that the sedation protocol was 'excellent' or 'enough' for peroral DBE. Eleven patients (32.3%) required a bolus injection of pentazocine. Age <60 years and a total procedure time of >70 min were significant risk-factors for pentazocine use. CONCLUSIONS: A combination of propofol via TCI pump, bolus injection of pentazocine as needed, and BIS monitoring was a safe and effective procedure for peroral DBE. Reasonable satisfaction indices were obtained from both patients and endoscopists. Pentazocine was required for young patients and in cases with longer procedure times.

Involvement of µ- and δ-opioid receptor function in the rewarding effect of (±)-pentazocine.

Most opioid receptor agonists have abuse potential, and the rewarding effects of opioids can be reduced in the presence of pain. While each of the enantiomers of pentazocine has a differential pharmacologic profile, (±)-pentazocine has been used clinically for the treatment of pain. However, little information is available regarding which components of pentazocine are associated with its rewarding effects, and whether the (±)-pentazocine-induced rewarding effects can be suppressed under pain. Therefore, the present study was performed to investigate the effects of pain on the acquisition of the rewarding effects of (±)-pentazocine, and to examine the mechanism of the rewarding effects of (±)-pentazocine using the conditioned place preference paradigm. (±)-Pentazocine and (-)-pentazocine, but not (+)-pentazocine, produced significant rewarding effects. Even though the rewarding effects induced by (±)-pentazocine were significantly suppressed under pain induced by formalin, accompanied by increase of preprodynorphin mRNA levels in the nucleus accumbens, a high dose of (±)-pentazocine produced significant rewarding effects under pain. In the normal condition, (±)-pentazocine-induced rewarding effects were blocked by a low dose of naloxone, whereas the rewarding effects induced by high doses of pentazocine under pain were suppressed by naltrindole (a δ-opioid receptor antagonist). Interestingly, (±)-pentazocine did not significantly affect dopamine levels in the nucleus accumbens. These findings suggest that the rewarding effects of (-)-pentazocine may contribute to the abuse potential of (±)-pentazocine through µ- as well as δ-opioid receptors, without robust activation of the mesolimbic dopaminergic system. We also found that neural adaptations can reduce the abuse potential of (±)-pentazocine under pain.

[Anesthetic management for caesarean delivery in a parturient with achondroplasia].

A 27-year-old parturient (height, 130 cm; weight, 43 kg) with achondroplasia, which is characterized by rhizomeric short stature, large head and frontal bossing, was scheduled for elective caesarean section (C/S) because of her contracted pelvis. Her first delivery had been performed by C/S under general anesthesia at a regional hospital 6 years before. Preoperative airway assessment showed normal mouth opening and mobile cervical spine. Since she had anxiety about needle puncture and refused neuraxial blockade and since we considered the trachea could be intubated, we decided to perform C/S under general anesthesia at 37 weeks of gestation. The patient and baby had an uneventful perioperative course. Underdevelopment of bone formation results in characteristic craniofacial and vertebral abnormalities in patients with achondroplasia. Anesthetic management of achondroplastic parturients should be specified to individual basis based on careful preoperative assessment of craniofacial and vertebral deformities.

[Treatment of intrathecal fentanyl-induced itch with pentazocine: a case report].

Pentazocine has activities both of kappa-opioid receptor agonist and weak micro-opioid receptor antagonist. Recent study has suggested that kappa-opioid receptor agonists have antipruritic effects. We experienced a case of pentazocine inhibiting itch evoked by intrathecal fentanyl in a patient with idiopathic pulmonary fibrosis (IPF). A 50-year-old woman with IPF was diagnosed with fallopian tube abscess and which necessitated emergency surgery. We mainly performed regional anesthetic management to prevent acute exacerbation of IPF by tracheal intubation under general anesthesia. About 30 minutes after intrathecal administration of a combination of bupivacaine and fentanyl, she began to complain of itch. Although propofol was given intravenously, pruritus still recurred. Following that, when pentazocine was administered intravenously, pruritus disappeared immediately and then never recurred. Therefore, it is suggested that pentazocine can be useful in reducing pruritus on intrathecal opioid-induced itch. Future studies are necessary to evaluate the efficacy of pentazocine for the treatment and prevention of opioid-induced itch.

Opioids for acute pancreatitis pain.

BACKGROUND: Acute pancreatitis is an acute inflammatory process of the pancreas that may also involve adjacent tissues and/or remote organ systems. Abdominal pain is the main symptom and is usually accompanied by nausea, vomiting and fever. Opoids are commonly used to manage pain in acute pancreatitis but there are still some uncertainties about their clinical effectiveness and safety. OBJECTIVES: To assess the effectiveness and safety of opioids for treating acute pancreatitis pain. SEARCH METHODS: The search strategy included the Cochrane Upper Gastrointestinal and Pancreatic Diseases Review Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2013, Issue 6), MEDLINE (from 1950 to June 2013) and EMBASE (from 1980 to June 2013). There were no restrictions by language or publication status. SELECTION CRITERIA: We considered randomised clinical trials (RCTs) assessing the effectiveness of any opioid drug used for treating acute pancreatitis pain. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risks of bias and extracted data. We estimated risk ratios (RRs) for dichotomous data and calculated a 95% confidence interval (CI) for each RR. We performed an intention-to-treat (ITT) analysis. We undertook meta-analysis for some outcomes. MAIN RESULTS: We included five RCTs with a total of 227 participants (age range 23 to 76 years; 65% men) with acute pancreatitis pain. The opioids assessed were intravenous and intramuscular buprenorphine, intramuscular pethidine, intravenous pentazocine, transdermal fentanyl and subcutaneous morphine.One RCT, comparing subcutaneous morphine with intravenous metamizole reported non-significant reduction in the number of participants with improvements in pain intensity (primary outcome) (RR 0.50, 95% CI 0.19 to 1.33). Three studies compared analgesia using opioids with non-opioid treatments. After excluding one study that used opioids through continuous intravenous infusion, there was a decrease in the number of patients requiring supplementary analgesia (RR 0.53, 95% CI 0.30 to 0.93). In a single study, there were no differences in the number of patients requiring supplementary analgesia between buprenorphine and pethidine (RR 0.82, 95% CI 0.61 to 1.10).Pancreatitis complications were not associated with a significant difference between the drugs tested. No clinically serious or life-threatening adverse events occurred related to treatment. No differences for this outcome were found between opioid and non-opioid treatments, or for type of adverse event (nausea-vomiting and somnolence-sedation). One death in the procaine group was reported across all the trials.One RCT comparing pethidine with intramuscular buprenorphine reported non-significant differences of supplementary analgesic, adverse events or deaths. One RCT comparing fentanyl with placebo found no difference in adverse events.The findings of this review are limited by the lack of information to allow full appraisal of the risk of bias, the measurement of relevant outcomes and the small numbers of participants and events covered by the trials. AUTHORS' CONCLUSIONS: Opioids may be an appropriate choice in the treatment of acute pancreatitis pain. Compared with other analgesic options, opioids may decrease the need for supplementary analgesia. There is currently no difference in the risk of pancreatitis complications or clinically serious adverse events between opioids and other analgesia options.Future research should focus on the design of trials with larger samples and the measurement of relevant outcomes for decision-making, such as the number of participants showing reductions in pain intensity. The reporting of these RCTs should also be improved to allow users of the medical literature to appraise their results accurately. Large longitudinal studies are also needed to establish the risk of pancreatitis complications and adverse events related to drugs.

Administration of additional analgesics can decrease the incidence of paradoxical reactions in patients under benzodiazepine-induced sedation during endoscopic transpapillary procedures: prospective randomized controlled trial.

AIM: The aim of the present study was to evaluate the efficacy and safety of giving pentazocine as an analgesic with benzodiazepine during endoscopic retrograde cholangiopancreatography (ERCP). METHODS: The paradoxical reactions (PR) incidence was evaluated as an indicator of usefulness. Transcutaneous arterial carbon dioxide tension (PtcCO(2) ) was evaluated as an indicator of safety. A total of 160 patients were enrolled. Subjects were randomly divided into two groups; group 1 sedated with midazolam only and group 2 sedated both with midazolam and pentazocine (7.5 mg). RESULTS: The initial dosage introduced sedation before procedure was significantly higher in group 1. The occurrence rate of PR's in group 1 was significantly higher compared to that in group 2 (P = 0.0108). Although maximum PtcCO(2) observed during sedation did not differ between the two groups (48.7 ± 7.2, 50.3 ± 7.6 mmHg, respectively),maximum PtcCO(2) during the first 15 min after the start of sedation was significantly higher in group 2 than in group 1 (P = 0.0294). In multivariate analysis, procedure duration (odds ratio [OR] = 1.048) and midazolam dose (OR = 1.221) were predictive factors for PR. CONCLUSION: The administration of pentazocine is significantly reduced the incidence of PR's in patients under midazolam induced sedation during ERCP.

Drug discrimination in pigeons trained to discriminate among morphine, U50488, a combination of these drugs, and saline.

This study compared fixed-ratio (FR) and fixed-interval (FI) schedules to investigate the discriminative stimulus properties of µ-opioid and/or κ-opioid receptor agonists. Pigeons were trained to discriminate among morphine (µ agonist), U50488 (κ agonist), the combination, and saline under FR 20-s or FI-300-s schedule. After training, correct-key responding averaged 94.4 (FR) and 66.5% (FI) after administration of training drugs. Dose-response curves were generally quantal under the FR and graded under the FI schedules, but highly variable among subjects under the FI. Under the FR schedule, the dose of naltrexone that blocked morphine's discriminative stimuli also blocked U50488. Combining high doses of morphine with low doses of U50488 produced responding on the morphine key and combining high doses of U50488 with low doses of morphine produced responding on the U50488 key. Combining high doses of both drugs produced responding on the drug-combination key. Increasing d,l-pentazocine doses shifted responding from the saline key to the U50488 key, then to the morphine key, and finally to the drug-combination key. Butorphanol and ethylketocyclazocine produced similar effects, except responding on the morphine key increased before responding on the U50488 key. The four-choice procedure under the FR schedule has the potential for determining the discriminative stimulus effects of mixed agonists.

Pentazocine increases bispectral index without surgical stimulation during nitrous oxide-sevoflurane anesthesia.

Although there have been a large number of reports on the effects of opioids on the bispectral index (BIS) during anesthesia, the effects of pentazocine on the BIS have not been reported. In this study, 60 patients scheduled for elective oral surgery [30 females, 30 males; all American Society of Anesthesiologists Physical Status (ASA PS) category 1] were enrolled in the trials. Maintaining gender parity, we randomly assigned the patients to one of three groups: pentazocine group (0.3 mg/kg; n = 20), fentanyl group (1 µg/kg; n = 20), or saline group (n = 20); these opioids were administered intravenously 15 min after the intubation. Anesthesia was induced with thiopental and vecuronium bromide and maintained with nitrous oxide (4 l/min)-oxygen (2 l/min)-sevoflurane (1%). At 15 min after the intubation, mean arterial blood pressure (MAP), heart rate (HR), and BIS index were recorded as baseline values. MAP, HR, and BIS values were measured at 2.5-min after the intubation up to 30 min. All data were expressed as the mean ± standard deviation. Differences in BIS values, MAP, and HR among the three groups throughout the experiment were analyzed using two-way repeated-measures analysis of variance (ANOVA), and demographic data among the three groups were analyzed using one-way ANOVA. Post hoc comparisons were performed using Fisher's protected least significant difference test. A P value of <0.05 was considered to indicate statistically significance. MAP and HR showed no significant differences among the three groups during the study. BIS values significantly increased between 5 and 15 min after the intubation relative to the baseline value in the pentazocine group (P < 0.001), and BIS values in this group were significantly during this time period than those in the fentanyl and saline group (P < 0.001). BIS values were not significantly different between the fentanyl group and saline group. These results indicated that pentazocine, but not fentanyl, under nitrous oxide-sevoflurane anesthesia caused a statistically significant increase in BIS in our patients.

[Effect of pentazocine on the bispectral index during nitrous oxide-sevoflurane anesthesia].

BACKGROUND: The effect of pentazocine on the bispectral index (BIS) has not been reported. In this study, we have examined whether pentazocine alters the bispectral index during nitrous oxide-sevoflurane anesthesia. METHODS: Thirty surgical patients were enrolled in this double-blind, randomized study. Anesthesia was induced with thiopental and vecuronium and maintained with nitrous oxide-sevoflurane with the bispectral index maintained at approximate 40. Under stable anesthetic condition before surgery, patients were assigned to receive either a bolus of pentazocine 0.3 mg x kg(-1), 0.6 mg x kg(-1) or the same volume of saline 15 min after induction. Blood pressure (BP), heart rate (HR) and BIS were measured every 2.5 min from 2.5 min before induction until 30 min after induction. RESULTS: BP and HR showed no changes after pentazocine administration compared with control group. BIS showed no significant change in the saline group, but it increased significantly in the pentazocine group. When pentazocine was administered 15 min after induction, BIS increased significantly 20, 22.5, 25, 27.5 and 30 min after induction compared with the control group. The increase of BIS by pentazocine showed no dose-dependent effect in our present study. CONCLUSIONS: We observed that intravenous pentazocine caused a significant increase in BIS under nitrous oxide-sevoflurane anesthesia. The depth of sedation should be assessed carefully using a bispectral index monitor when pentazocine is used together.

Boerhaave's syndrome after pentazocine-induced vomiting in a 21-year-old male with asthma: a case report.

Boerhaave's syndrome is an uncommon syndrome characterized by spontaneous rupture of the oesophagus with a high mortality rate. While excessive alcohol intake and binge-eating are the classic precipitants of this syndrome, medication-induced vomiting causing Booerhave's is quite uncommon. Traditionally managed operatively, conservative management is being increasingly reported in selected cases. We report the case of 21-year-old male with who developed sudden onset chest pain and dyspnoea after pentazocine induced vomiting. He was referred after lack of response to initial treatment for acute severe asthma. A chest CT scan showed pneumomediastinum, subcutaneous emphysema and oesophageal tear. He was managed conservatively with oxygen therapy, nil per mouth and antibiotics with improvement of symptoms and discharge after 8 days.

Estimating attractiveness for abuse of a not-yet-marketed "abuse-deterrent" prescription opioid formulation.

OBJECTIVE: The present study builds on research to model abusers' perceptions of particular analgesics' attractiveness for abuse and extends these methods to derive an estimate of attractiveness for abuse of a not-yet-marketed abuse-deterrent formulation (ADF) of a prescription opioid (Remoxy), Pain Therapeutics, Inc., San Mateo, CA, and King Pharmaceuticals, Inc., Bristol, TN). In a previous study, the Opioid Attractiveness Technology Scaling (OATS) method identified, from a drug abuser's point of view, the particular features of a prescription opioid relevant to its attractiveness for recreational use. A second online sample rated the extent to which these features applied to particular products they had actually used/abused. These data were used to model the abusers' overall preference for prescription opioids they had used/abused. DESIGN: In the present study, this method was applied to a not-yet-marketed ADF using substance abuse counselors as proxies for prescription opioid abusers. Thirty-eight counselors were given materials describing the new ADF along with four known products. RESULTS: Thirty-two counselors demonstrated sufficient agreement with abusers' ratings of the overall attractiveness of these drugs. The overall model yielded a significant pseudo R(2) of 0.15 (P < 0.001), with increasing model fit based on preferred route of administration, from swallowing whole (pseudo R(2) = 0.06; P < 0.001) and best for those who preferred to inject (pseudo R(2) = 0.40; P < 0.001). Data from a cross-validation group of 16 counselors/proxies were used to calculate the OATS scores for the five rated drugs and revealed significant differences between the ADF and OxyContin (Purdue Pharma LP, Stamford, CT), Percocet (Endo Pharmaceuticals, Chadds Ford, PA), and Vicodin (Abbott Laboratories, Abbott Park, IL), but not Talwin NX (Sanofi-aventis, Bridgewater, NJ), which was identified in the prior study as a highly unattractive drug for recreational purposes. CONCLUSIONS: The OATS method shows promise for providing pre-marketing estimates of attractiveness for abuse of not-yet-marketed ADFs.