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.

Nerve Block for Pain Relief During Arthroscopic Rotator Cuff Repair.

BACKGROUND: Although arthroscopic rotator cuff repair (ARCR) often results in good outcomes, some patients have severe pain postoperatively. This study investigated the efficacy of nerve block for ARCR. METHODS: This study was retrospective, and consent was obtained from all patients. We divided 50 patients who had undergone ARCR into 4 groups: continuous interscalene nerve block was performed for 11 patients (continuous-injection group), single interscalene nerve block for 10 (single-injection group), suprascapular nerve block for 8 (suprascapular group), and intravenous analgesic administration for 10 (intravenous group). Eleven patients received no nerve block (control group). We evaluated diclofenac sodium and pentazocine dosing, visual analog scale (VAS) scores, and perioperative complications in each group. VAS scoring was done immediately after surgery and 1 and 6 hours and 1, 2, 3, 7, and 14 days postoperatively. RESULTS: The doses of diclofenac sodium and pentazocine did not differ between groups. VAS scores immediately after surgery and at 1 and 6 hours after surgery were significantly lower in the single-injection and continuous-injection groups than in the suprascapular, intravenous, and control groups. VAS score at 1 day postoperatively was significantly lower in the continuous-injection group than in the other groups. One patient in the continuous group reported temporary paralysis of the fingers and drug solution leakage. CONCLUSION: Interscalene nerve blocks yielded good pain relief for ARCR. Although continuous interscalene nerve block produced continuous pain relief, complications are a concern.

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).

Clinical and socio-demographic determinants of pentazocine misuse among patients with sickle cell disease, Benin City, Nigeria: a case-control study.

INTRODUCTION: Opioids are a mainstay in sickle cell disease (SCD) pain care. Opioids are known to cause physical and/or psychological dependence. Increasingly, a significant number of Nigerian SCD patients ("Pentaholics") are observed to abuse pentazocine. This trend is associated with new patterns of medical complications. This study aimed to describe the local spectrum of pentazocine abuse complications and identify possible clinical and socio-demographic determinants. METHODS: We conducted a case control (age matched) study involving 50 booked SCD patients (25 cases and 25 controls) receiving care at the University of Benin Teaching Hospital, Benin City, Nigeria. Relevant clinical and socio-demographic details were collected and analyzed. Associations of categorical variables were tested using chi square or Fishers exact test. RESULTS: The median participants' age and duration of pentazocine abuse/self-use were 32 and 7 years respectively. Pentazocine injections were gotten from local pharmacies and patent medicine stores without any need for physician prescriptions (84% of cases). The buttocks, the thigh and the upper arm/deltoid were the commonest site of injection. Major complications observed were chronic ulcers on the thigh, deep wounds with abscess, healed scar at multiple sites, lower limb swelling and venous thrombosis. Working in healthcare fields/hospitals (Doctor, Nurses, Pharmacists) was significantly associated with pentazocine abuse. CONCLUSION: Health personnel or hospital workers living with SCD are more likely to abuse pentazocine. There is need for prompt triage and optimal control of acute sickle pain, institutional protocols for pain management and strict regulations on supply of prescription drugs such as pentazocine.

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.

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.

Digital gangrene induced by inadvertent intra-arterial cocktail injection of anesthetic agents such as pentazocine, promethazine, and atropine: A serious adverse drug experience.

Gangrenous changes in skin due to accidental intra-arterial injection of promethazine and pentazocine have been reported. Accidental intra-arterial injection is most commonly encountered in the antecubital fossa. However, recent reports in the radial and ulnar arteries have also been encountered. We hereby report a serious, preventable adverse drug experience in the form of digital gangrene induced by inadvertent intra-arterial cocktail injection of anesthetic agents such as pentazocine, promethazine, and atropine, which seems to be in the radial artery as the lateral three digits and dorsum of the hand are affected.

Subarachnoid Block-Induced Deafferentation Pain Successfully Treated with Pentazocine.

Deafferentation pain induced by subarachnoid block (SAB) is rare, but it can appear in the form of recurrent phantom lower limb pain, new acute-onset stump pain in amputees, lower limb pain in patients with tabes dorsalis, and neuropathic pain. We have previously reported that thiopental is an effective treatment for deafferentation pain induced by therapeutic SAB applied to treat neuropathic pain of central origin. Here, we report the case of an amputee who developed new stump pain in his lower limb immediately after subarachnoid tetracaine was administered prior to appendectomy. A 51-year-old man who had previously undergone right below-knee amputation for acute arterial thrombosis, and who had not previously experienced chronic phantom limb or stump pain, was scheduled for emergency open appendectomy. For anesthesia, we induced SAB with a hyperbaric tetracaine solution. No paresthesia occurred during administration. However, the patient immediately complained of severe, lightning-bolt pain in the right lower limb stump after the SAB was established. He was given intravenous pentazocine, which promptly resolved the pain. Appendectomy was then performed under sedation using intravenous midazolam. The patient did not experience further deafferentation pain during his hospital stay and has reported no stump pain since discharge from the hospital. This case report suggests that SAB induces deafferentation pain in some patients and that this unusual pain can be treated with pentazocine.

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.

Diagnostic Yield and Complications of EBUS-TBNA Performed Under Bronchoscopist-directed Conscious Sedation: Single Center Experience of 1004 Subjects.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) can be performed under either conscious sedation or general anesthesia. Herein, we describe the diagnostic yield and complications of EBUS-TBNA performed under bronchoscopist-directed conscious sedation. METHODS: This is a retrospective analysis of data collected in the bronchoscopy suite of this center on EBUS-TBNA or endoscopic ultrasound with a bronchoscope-guided fine needle aspiration (EUS-B-FNA) procedures performed between July 2011 and January 2016. All procedures were performed under bronchoscopist-directed conscious sedation with midazolam and pentazocine. The diagnostic yield, sample adequacy rate, complications, and doses of sedative agents are presented. RESULTS: Of the total 1005 EBUS-TBNA/EUS-B-FNA procedures performed during the study period, 1004 were performed under conscious sedation in spontaneously breathing subjects [mean (SD) age, 45.9 (15.8) years; 378 (37.6%) women]. The mean (SD) doses of midazolam and pentazocine used were 2.53 (1.8) mg and 30.9 (6.9) mg, respectively. The diagnostic yield of the procedure (972 subjects) was 61.2%. Complications related to EBUS were observed in 60 (5.9%) subjects. Majority of them were minor and self-limiting; major complications occurred in 11 (1.1%) subjects and included respiratory failure requiring assisted ventilation (n=6), arrhythmia (n=3), and hypotension (n=2). Escalation of the level of care was needed in only 8 (0.8%) subjects. CONCLUSION: EBUS-TBNA/EUS-B-FNA performed under bronchoscopist-guided conscious sedation was found to be safe and is associated with a reasonable diagnostic yield.

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.

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.

Estrogen facilitates and the kappa and mu opioid receptors mediate antinociception produced by intrathecal (-)-pentazocine in female rats.

Pentazocine, a mixed-action kappa opioid receptor (KOR) agonist, has high affinity for both KOR and the mu opioid receptor (MOR), and has been shown clinically to alleviate pain with a pronounced effect in women. However, whether local application of pentazocine in the spinal cord produces antinociception and the contribution of spinal KOR and MOR in mediating the effect of pentazocine in female rats remain unknown. Also, it is not known whether pentazocine-induced antinociception in females is estrogen-dependent. Hence, we investigated whether intrathecal (i.t.) (-)-pentazocine produces thermal antinociception and whether estrogen modulates the drug effect in female rats. Only the highest dose of pentazocine (500 nmol) was effective in producing antinociception in ovariectomized (OVX) rats. In contrast, pentazocine produced antinociception in estradiol-treated ovariectomized females (OVX+E) rats with the lowest effective dose being 250nmol. KOR or MOR mediated the effect of the lowest effective dose in OVX+E rats; however, MOR blockade extended the KOR-mediated effect of 500nmol pentazocine in both groups. In normally cycling females, the 250nmol dose was effective in producing antinociception at the proestrous, but not at the diestrous stage of the estrous cycle. Thus, estrogen facilitates and KOR or MOR mediates. the antinociceptive effect of i.t. (-)-pentazocine in female rats. Selective doses of (-)-pentazocine, with or without MOR blockade, may have a therapeutic benefit.

(+)-Pentazocine reduces oxidative stress and apoptosis in microglia following hypoxia/reoxygenation injury.

BACKGROUND: Sigma-1 receptors (σ1R) are highly expressed in neurons as well as microglia and have been shown to modulate the inflammatory response in the central nervous system and thus may serve as possible target for neuroprotective strategies. The aim of the present study was to test the effect of (+)-pentazocine, a putative σ 1R agonist, in an in vitro model of microglia activation. METHODS: Microglia (BV2 cells) was exposed (3h) to 1% oxygen and reoxygenation was allowed for 24h. Cells were treated with different concentrations (1, 10, 25 and 50µM) of (+)-pentazocine in the presence or absence of NE-100 (1µM), a well established σ1R antagonist. Cell viability and apoptosis were measured by cytofluorimetric analysis, whereas oxidative stress was evaluated by reduced glutathione (GSH) content and mitochondrial potential analysis. RESULTS: Our results showed that (+)-pentazocine was able to increase cell viability and restore mitochondrial potential at all concentrations whereas only 1 and 10µM were able to reduce significantly apoptotic cell death, to restore reduced glutathione intracellular content and prevent ERK1/2 phosphorylation. All these effects were abolished by concomitant treatment with NE-100. CONCLUSIONS: (+)-pentazocine exhibits significant dose dependent protective effects in our in vitro model of microglial activation thus suggesting that σ1R may represent a possible target for neuroprotection.

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.

Multicenter observational study comparing sedation/analgesia protocols for laser photocoagulation treatment of retinopathy of prematurity.

OBJECTIVE: The aim of this study was to identify the best sedation/analgesia protocol for laser photocoagulation (PC) of retinopathy of prematurity (ROP). STUDY DESIGN: This multicenter observational study included five hospitals, each using a specific sedation/analgesia protocol: local anesthesia with oxybuprocaine hydrochloride (Group L); intravenous pentazocine (Group P); intravenous fentanyl (Group F); air, oxygen and sevoflurane (AOS) inhalation (Group I). The groups were compared for pain responses, vital signs and adverse events. RESULTS: Heart rates and systemic blood pressures were elevated by PC in Groups L and P and Groups L, P and F, respectively. Moreover, poor analgesic efficacy was recognized in Groups L, P and F. In contrast, Group I experienced hypothermia, enteral feeding intolerance and apnea more frequently. CONCLUSION: From the viewpoint of sedation/pain relief, AOS anesthesia should be the best protocol. However, considering all the various factors together, the most reasonable one can be varied based on the patient's condition and hospital.

Pentazocine-induced contractures: Dilemma in management.

Pentazocine is a commonly used synthetic opioid analgesic for moderate to severe pain secondary to various conditions. Complications of parenteral opioid abuse including localized ulcerations, abscess, indurations, and sclerosis are well-documented. We present a rare case of drug abuse due to pentazocine (Fortwin) in a 32-year-old female, who had severe myogenic contractures of her knee joints.

Pentazocine use among people who inject drugs in India.

Data regarding prevalence of Pentazocine use is sparse and intervention strategies aimed at it are meager. In view of the fact that Pentazocine has significant abuse potential contrary to what was earlier thought, along with the actuality that people who use injectable Pentazocine are at risk of various complications as HIV, this domain needs more attention. This review examines the extent of the problem of Pentazocine use with consequent effects on the overall health of the people. It is based on nationally representative large scale survey(s) and other reliable documented data on Pentazocine abuse. Possible strategies and future lines of actions have been delineated. Data suggests Pentazocine use from 0.1% to 21.8% in different parts of the country. Various reports have also linked it with unique health complications. Its use has been reported mostly among subjects seeking treatment, with recent reports suggesting increasing use at street level. The strategies to document the extent of injection drug use applied in most cases might not be adequate. There is a need for further research and monitoring to document the burden of the problem. Indirect methods to estimate the extent of problem may need to be implemented and regulatory mechanisms for prescription drug use may need to be strengthened.