Adverse effects of metamizole on heart, lung, liver, kidney, and stomach in rats.

BACKGROUND: Metamizole is banned in some countries because of its toxicity, although it is widely used in some European countries. In addition, there is limited information on its safety profile, and it is still debated whether it is toxic to the heart, lungs, liver, kidneys, and stomach. AIMS: Our study investigated the effects of metamizole on the heart, lung, liver, kidney, and stomach tissues of rats. METHODS: Eighteen rats were divided into three groups, wassix healthy (HG), 500 mg/kg metamizole (MT-500), and 1000 mg/kg metamizole (MT-1000). Metamizole was administered orally twice daily for 14 days. Meanwhile, the HG group received pure water orally. Biochemical, histopathologic, and macroscopic examinations were performed on blood samples and tissues. RESULTS: Malondialdehyde (MDA), total glutathione (tGSH), superoxide dismutase (SOD), and catalase (CAT) in the lung and gastric tissues of MT-500 and MT-1000 groups were almost the same as those of the HG (p > 0.05). However, MDA levels in the heart and liver tissues of MT-500 and MT-1000 groups were higher (p < 0.05) compared to the HG, while tGSH levels and SOD, and CAT activities were lower (p < 0.05). MDA levels of MT-500 and MT-1000 groups in the kidney tissue increased the most (p < 0.001), and tGSH levels and SOD and CAT activities decreased the most (p < 0.001) compared to HG. Metamizole did not cause oxidative damage in the lung and gastric tissue. While metamizole did not change troponin levels, it significantly increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine levels compared to HG. Histopathologically, mild damage was detected in heart tissue, moderate damage in liver tissue, and severe damage in renal tissue. However, no histopathologic damage was found in any groups' lung and gastric tissues. CONCLUSION: Metamizole should be used under strict control in patients with cardiac and liver diseases and it would be more appropriate not to use it in patients with renal disease.

Real-time and video-recorded pain assessment in beef cattle: clinical application and reliability in young, adult bulls undergoing surgical castration.

Bovine pain assessment relies on validated behavioral scales related to normal and pain-related behaviors. This study investigated the reliability and applicability of real-time and video-recorded pain assessment, and their agreement, in young, adult bulls undergoing surgical castration. Ten Nelore and nine Angus bulls underwent general anesthesia and surgical castration. Three-minute real-time observations and simultaneous videos were recorded at - 48 h (M0), before sedation, under fasting (M1), after surgery, 3 h after sternal recumbency (M2), after rescue analgesia (M3) and at 24 h (M4). Animals received morphine (after M2), dipyrone (after M3), and flunixin meglumine after surgical castration (M4). Two trained evaluators assessed real-time (n = 95) and video-recorded time-points (n = 95) using the Unesp-Botucatu Cattle Pain Scale (UCAPS). Both assessment methods inferred 'very good' reliability (≥ 0.81) with minimal bias, however, video-recorded assessment (4.33 ± 2.84) demonstrated slightly higher scores compared to real-time (3.08 ± 2.84). The results from this study suggest that UCAPS can be used in real-time or video-recorded to assess pain and guide analgesic therapy in cattle.

[New manifestation of a type 2-inflammation in the upper respiratory tract with nasal polyposis under treatment with an asthma biologic]. / Neumanifestation einer Typ-2-Inflammation im Bereich der oberen Atemwege mit Polyposis nasi unter einem Asthmabiologikum.

INTRODUCTION: For 7 years we gained experience of how asthma and chronic rhinosinusitis with nasal polyposis respond to biologics. In contrast, it is much less known, how ASA/NSAID intolerance (Widal's disease) behaves under biologicals. We therefore describe the case of a patient with both clinical conditions who reacted with a severe intolerance reaction under perioperative metamizole administration.

Neuroendocrine modulation by metamizole and indomethacin: investigating the impact on neuronal markers and GnRH release.

PURPOSE: Some evidence that non-steroidal anti-inflammatory drugs have neuroprotective effects indicates their potential for use in a new field. However, their effects on hormone secretion have yet to be adequately discovered. Therefore, we aimed to evaluate the effects of metamizole and indomethacin on neuronal markers as well as the GnRH expression in the GT1-7 cell line. METHODS: The effects of these drugs on proliferation were evaluated by MTT analysis. The effect of 10-50-250 µM concentrations of the drugs also on the expression of neuronal factors and markers, including NGF, nestin and ßIII Tubulin, and additionally GnRH, was determined by the RT-qPCR method. RESULTS: NGF and nestin mRNA expressions were increased in all concentrations of both metamizole and indomethacin. No changes were detected in ßIII Tubulin. While metamizole showed an increase in GnRH mRNA expression, there was no change at 10 and 50 µM concentrations of indomethacin, but a remarkable decrease was observed at 250 µM concentrations. CONCLUSIONS: The results of our study showing an increase in the expression of neuronal factors reveal that metamizole and indomethacin may have possible neuroprotective effects. Moreover, the effects on the GnRH expression appear to be different. Animal models are required to confirm these effects of NSAIDs on neurons.

Prospective evaluation of the emetogenic profile and analgesic efficacy of intravenous ibuprofen and metamizole in the immediate postoperative period of pediatric acute appendicitis. / Evaluación prospectiva del perfil emético y la eficacia analgésica del ibuprofeno y el metamizol intravenosos en el postoperatorio inmediato de la apendicitis aguda pediátrica.

BACKGROUND: Literature comparing different alternatives for pain control in the immediate postoperative period of pediatric acute appendicitis (PAA) is scarce. MATERIALS AND METHODS: We prospectively compared the analgesic and emetogenic profile of intravenous ibuprofen and metamizole in the immediate postoperative period of PAA. For this purpose, we used a sample of patients operated on in 2021 in our center. Participants were recruited on arrival at the Emergency Department and histopathological confirmation of the diagnosis was obtained in all of them. Pain was evaluated every 8 hours after the surgery with validated visual analog scales ranging from 0 to 10 points. Repeated measures ANOVA was used to compare the evolution of pain in the 48 hours after surgery between the two groups. RESULTS: The sample included 95 patients (65% males) with a mean age of 9.7 years (sd: 3.14). 41 patients were treated with Ibuprofen (group 1) and 54 with metamizole (group 2). No significant differences were found in the level of pain either in the comparisons of point measurements or in its evolution in the 48 hours after surgery (p= 0.58). After adjusting for the received fluid therapy, children in the metamizole group had significantly more emetic episodes and needed significantly more doses of ondansetron. CONCLUSIONS: In our cohort, ibuprofen had a similar analgesic efficacy and a better emetogenic profile than metamizole in the immediate postoperative period of PAA. Future prospective, adequately controlled studies with larger sample sizes are needed to validate these findings.

INTRODUCCION: En la literatura existen pocas referencias que comparen las distintas alternativas disponibles para controlar el dolor en el postoperatorio inmediato de la apendicitis aguda pediátrica (AAP). MATERIAL Y METODOS: Comparación prospectiva del perfil analgésico y emético del ibuprofeno y el metamizol intravenosos en el postoperatorio inmediato de la AAP, para lo cual se recurre a una muestra de pacientes operados en 2021 en nuestro centro. Los participantes fueron reclutados a su llegada a Urgencias, obteniéndose confirmación histopatológica del diagnóstico en todos ellos. La evaluación del dolor se llevó a cabo cada 8 horas tras la cirugía mediante escalas analógicas visuales validadas, con valoraciones entre los 0 y los 10 puntos. Se realizó un ANOVA de las medidas repetidas entre los dos grupos para comparar la evolución del dolor en las 48 horas posteriores a la cirugía. RESULTADOS: La muestra estaba compuesta por un total de 95 pacientes (65% de ellos varones) con una edad media de 9,7 años (DT: 3,14). 41 pacientes fueron tratados con ibuprofeno (grupo 1) y 54 con metamizol (grupo 2). No se hallaron diferencias significativas en lo que respecta al dolor, ni en las comparaciones de las mediciones puntuales, ni en su evolución en las 48 horas posteriores a la cirugía (p= 0,58). Una vez realizado el ajuste correspondiente a la terapia de fluidos recibida, los niños del grupo metamizol tuvieron significativamente más episodios eméticos y necesitaron significativamente más dosis de ondansetrón. CONCLUSIONES: En nuestra cohorte, el ibuprofeno tuvo una eficacia analgésica similar y un mejor perfil emético que el metamizol en el postoperatorio inmediato de la AAP. Se hacen necesarios nuevos estudios prospectivos, adecuadamente controlados y con mayor tamaño muestral que validen estos hallazgos.

Discovery of GPX4 inhibitors through FP-based high-throughput screening.

Ferroptosis is a form of non-apoptotic cell death, regulated by phospholipid hydroperoxide glutathione peroxidase 4 (GPX4), a selenoprotein with a selenocysteine residue (sec) in the active site. GPX4 is a promising target for cancer cells in therapy-resistant conditions via ferroptosis, which can reduce the level of lipid reactive oxygen species (ROS). So far, all existing GPX4 inhibitors covalently bind to GPX4 via a reactive alkyl chloride moiety or masked nitrile-oxide electrophiles with poor selectivity and pharmacokinetic properties and most were obtained by cell phenotype-based screening. Lacking of effective high-throughput screening methods for GPX4 protein limits the discovery of GPX4 inhibitors. Here, we report a fluorescence polarization (FP)-based high throughput screening (HTS) assay for GPX4-U46C-C10A-C66A in vitro, and found Metamizole sodium from our in-house compound library inhibits GPX4-U46C-C10A-C66A enzyme activity. Structure-activity relationships (SAR) demonstrated the importance of sulfonyl group on interaction between Metamizole sodium and GPX4-U46C-C10A-C66A. Our FP assay could be an effective tool for discovery of GPX4 inhibitors and Metamizole sodium was a potential inhibitor for GPX4 in vitro.

Fatal pulmonary hemorrhage, pneumothorax and skin necrosis caused by IRIS to an Aspergillus flavus infection in a young patient with metamizole associated agranulocytosis.

We report the case of a young female with steroid-dependent ulcerative colitis (UC) who developed a complex systemic infection with Aspergillus flavus. This occurred following a UC relapse while vacationing in the Middle East, leading to extended use of metamizole and subsequent agranulocytosis. On her return to Germany, she was hospitalized for neutropenic sepsis and later transferred to our hospital due to persistent cytopenia and suspected Hemophagocytic Lymphohistiocytosis (HLH). Despite initial stabilization with targeted treatment for pulmonary Aspergillus flavus infection, her condition rapidly deteriorated following the onset of an Immune Reconstitution Inflammatory Syndrome (IRIS), which manifested as skin necrosis and pneumothorax after the replenishment of neutrophil granulocytes. The patient eventually died from an unmanageable pulmonary hemorrhage. Microscopy of skin necroses showed a massive presence of Aspergillus flavus, but tissue culture remained negative, suggesting effective antifungal treatment yet delayed phagocytosis due to agranulocytosis. This case underscores the need to consider IRIS in immunosuppressed patients who worsen despite aggressive and appropriately targeted treatment, highlighting its potential beyond the commonly recognized context in HIV-positive patients.

Case Report: Simultaneously Induced Neutropenia and Hemolysis After a Single Metamizole Dose.

BACKGROUND AND OBJECTIVE: Metamizole is a non-opioid ampyrone sulfonate compound with potent analgesic, antipyretic, and spasmolytic effects. Agranulocytosis is a rare life-threatening complication of metamizole. CASE: Here, we present the case of a 62-year-old patient who developed agranulocytosis as well as hemolysis after a single administration of metamizole. CONCLUSION: This case illustrates the inherent allergic potential of metamizole and its effects on different hematopoietic cell types.

The effects of metamizole on hematopoietic progenitor cells: Suppression of hematopoiesis stimulation in vitro.

BACKGRAUND: There is evidence that the adverse effects of metamizole occur due to the effect of the drug on the hematopoietic stem/progenitor cells, and therefore, the disruption of hematopoiesis. Therefore, our study aimed to evaluate the effects of metamizole on hematopoietic stem/progenitor cells using cell culture techniques. MATERIAL AND METHODS: In our study, samples were taken from stem cell products of healthy allogeneic stem cell transplant donors. The colony-forming unit (CFU) assay was used for the cells obtained from these samples. In addition, the drug effects on cell proliferation were evaluated with the MTT. Furthermore, the cell colonies were labelled with immunofluorescent antibodies and the effects of metamizole on cell types formed in culture were evaluated. RESULTS: We determined that metamizole negatively affects the proliferation of cells, especially starting from 10 µM. As a result of the evaluation of colonization, we saw that the number of colonies decreased with increasing concentrations. Granulocyte-macrophage colonies were more affected at increasing concentrations than other colonies. As a result of the evaluations of our in vitro study, it was also shown as an important finding that the individual effects of the drug were highly variable. CONCLUSION: CFU method can be used as a suitable method to investigate the effects of drugs and toxic substances on hematopoiesis. We also think it may be suitable for pre-analysing hematopoietic side effects in new drug research. In addition, using stem cell samples in studies may contribute more easily to the in vitro simulation of hematopoietic differentiations (Fig. 7, Ref. 29). Text in PDF www.elis.sk Keywords: metamizole, hematopoietic progenitor cells, hematopoiesis, CFU assay, adverse effect.

The analysis of reason for the presence and treatment of chronic inflammation of the paranasal sinuses in own material.

SummaryIntroduction. . The aim of the study was the analysis of reasons for the occurrence and treatment results of chronic inflammation of the paranasal sinuses in own materail. MATERIAL AND METHODS: The study was performed on 520 women aged 18 - 87 and 789 men aged 19-85, diagnosed and treated for the chronic inflammation of the paranasal sinuses in 2016 - 2020. The analysis was based on disease medical history, taking into account: gender; age of patients; type of symptoms; allergy diagnosis; probable cause of inflammation; type of anatomical anomalies; assessment of the advancement of lesions based on CT images in the Lund- Mackay scale; number of operations; histopathological result of the removed lesions; complications that occured after surgical treatment.ResultsThe study showed that the hospitalized patients were most often aged 41-50, 51-60 and 31-40 among women and men aged 51-60, 41-50 and 31- 40 . The results of allergological diagnostics among patients with chronic inflammation of the paranasal sinuses showed that women were most often allergic to pyralgin + ketonal + paracetamol + ibuprofen in 4.50 % , to penicillins in 1.07 % and to house dust saprophytes in 0.92%, while among men, positive reactions were found in 3.36 % for pyralgin + ketonal + paracetamol + ibuprofen, 0.99% for house dust saprophytes and 0.92% for cats and dogs fur. Absence of anatomical anomalies was found among 20.75 % of woman and 26.36 % of men, but most often they occurred in the form of nasal septal curvature and excessively dilated middle nasal turbinate. In the histopathological examination of the lesions from the paranasal sinuses, the following were found: chronicinflammation of mucous membrane, chronic polypoid inflammation, chronic cystic inflammation and chronic allergic inflammation. CONCLUSIONS: The main symptoms among patients with chronic inflammation of paranasal sinuses were: nasal congestion + rhinorrhea, nasal congestion + rhinorrhea + smell impairment and nasal congestion + rhinorrhea+ headache. The most common probable causes for chronic inflammation of nasal sinuses among the examined patients were: anatomical anomalies, allergies, irritant factors, including tobacco smoke. Depending on the assessment of the severity of changes in the paranasal sinuses according to the Lund- Mackay scale, it appears that medium and large inflammatory lesions prevailed in the examined patients. KEY WORDS: reason/cause, occurrence, treatment results, chronic inflammation of the paranasal sinuses.

Additive or synergistic analgesic effect of metamizole on standard pain treatment at home after arthroscopic shoulder surgery: A randomised controlled superiority trial.

BACKGROUND: There is growing evidence that the analgesic effect of metamizole is mediated at least partly by central mechanisms, including the endocannabinoid/endovanilloid system. Consequently, metamizole may have additive or even synergistic analgesic effects with paracetamol and nonsteroidal anti-inflammatory drugs (NSAID). OBJECTIVE: This study aimed to assess if triple therapy with metamizole, ibuprofen and paracetamol (MIP) is superior to double therapy with ibuprofen and paracetamol (i.p.) in treating pain at home after ambulatory arthroscopic shoulder surgery. DESIGN/SETTING/PATIENTS/INTERVENTION: In this double-blind, controlled, high-volume single centre, superiority trial, 110 patients undergoing elective ambulatory arthroscopic shoulder surgery were randomised to receive either MIP ( n  = 55) or i.p. ( n  = 55) orally for 4 days between December 2019 and November 2021. Pain intensity at movement and rest, using a numeric rating scale (NRS), perceived pain relief, use of rescue medication and adverse effects of study medication were recorded at the post-anaesthesia care unit (PACU) and on postoperative day (POD) 1 to 4 and 7. Quality of Recovery (QoR) and satisfaction with study medication were measured at POD 7 with telephone follow-up. MAIN OUTCOME MEASURE: The primary outcome measure was postoperative pain intensity on movement measured by an 11-point NRS (where 0 = no pain and 10 = worst pain imaginable) on POD 1. RESULTS: For the primary outcome, superiority of MIP in reducing postoperative pain at movement on POD 1 was not confirmed: mean difference NRS [95% confidence interval (CI), -0.08 (-1.00 to 0.84)]. For pain on movement and at rest, no significant differences were found between groups in the PACU nor on POD 1 to 4 or day 7. Nausea was reported significantly more frequently in the metamizole group (22.6 vs. 58.5; P  < 0.001). Other adverse effects of study medication, rescue opioid consumption, perceived pain relief, QoR at POD 7, and overall patient satisfaction were similar in both groups. CONCLUSION: Clinically, triple oral treatment with metamizole, paracetamol and ibuprofen is not superior to oral paracetamol and ibuprofen in multimodal pain treatment at home after ambulatory arthroscopic shoulder surgery. TRIAL REGISTRATION: European Union Clinical Trials Register 2019-002801-23 and Clinicaltrials.gov NCT04082728.

A case of chronic disseminated candidiasis in metamizole-induced neutropaenia.

Chronic disseminated candidiasis (CDC) is a severe complication of a disseminated yeast infection mainly seen after prolonged chemotherapy-induced neutropaenia in the context of haematological malignancy. We present a case of CDC in a patient with metamizole-induced neutropaenia. To the best of our knowledge, this is the first case described in this context. Furthermore, we highlight the role of steroids in the management of this disease.

Unmasking of Metamizole-induced Liver Injury by Simult aneous Development of Characteristic Agranulocytosis.

BACKGROUND: Metamizole is one of the most used analgesic, antipyretic, and spasmolytic agents in many countries worldwide. While metamizole-induced agranulocytosis is an, albeit seldom, well-known adverse event, metamizole-associated drug-induced liver injury has been reported rarely in the literature and hence often remains unconsidered. Here, we present a unique case where metamizole-induced hepatotoxicity got unmasked by the simultaneous development of characteristic agranulocytosis. CASE REPORT: A 22-year-old woman without known conditions presented with a new onset of fever, jaundice, and maculopapular rash and explicitly denied intake of any new substances. Laboratory tests showed liver injury, granulopenia, and positive anti-nuclear and anti-mitochondrial (AMA-M2) antibodies. Liver biopsy revealed a histological pattern characteristic of drug-induced liver injury and bone marrow biopsy, the classical picture of metamizole-induced agranulocytosis. Indeed the in-depth interview of the patient unveiled metamizole consumption over the last two months. Therefore, we could diagnose metamizole-induced hepato- and myelotoxicity. Accordingly, steroid therapy led to normalization of liver parameters and stimulation with granulocyte colony- stimulating factor to leukocyte recovery. CONCLUSION: This case report is intended to increase the awareness of metamizole-associated druginduced liver injury which should always be kept in mind due to its occasionally life-threatening course. Diagnosis can be difficult particularly if anamnesis and written records are without hints for prior metamizole intake.

Efficacy of single-shot adductor canal block before Versus after primary total knee arthroplasty - Does timing make a difference? A randomized controlled trial.

BACKGROUND: Total knee arthroplasty (TKA) is associated with severe postoperative pain. Multimodal analgesia, including peripheral nerve block, is recommended for post-operative pain relief. Administration of some pain medications prior to surgery has shown to be more effective than after the operation. This is a prospective, randomized controlled trial designed to compare the analgesic efficacy of the adductor canal block (ACB) performed immediately before or immediately after primary total knee arthroplasty (TKA). We hypothesized that ACB before the surgery will reduce postoperative pain and improve knee function. METHODS: A total of 50 patients were enrolled and randomized into 2 groups, with 26 patients receiving a preoperative ACB and 24 receiving a postoperative ACB. RESULTS: Treatment groups were similar in terms of gender (p = .83), age (p = 0.61) weight (p = .39) and ASA score. Average visual analogue scale (VAS) on arrival to the post-anesthesia care unit (PACU) were 4.9 ± 3.2 in the preoperative ACB versus 3.4 ± 2.8 for the postoperative ACB (p = .075). VAS scores at different time points as well as the mean, minimal and maximal reported VAS scores were not significantly different between the two groups. The cumulative quantities of Fentanyl administered by the anesthesia team was comparable between the groups. Similarly, the dosage of Morphine, Tramadol, Acetaminophen and Dipyrone showed only small variations. The Quality of Recovery Score, Knee Society Scores and knee range of motion did not differ between the groups. CONCLUSIONS: Our findings demonstrate no significant differences in patient total narcotics consumption, pain scores and functional scores, between preoperative and postoperative ACB in patients undergoing TKA. TRIAL REGISTRATION: The trial was registered at www.clinicaltrials.gov and was assigned the registration number NCT02908711. LEVEL OF EVIDENCE: level I randomized controlled trial.

Analgesic Medication in Fibromyalgia Patients: A Cross-Sectional Study.

There is no approved drug for fibromyalgia syndrome (FMS) in Europe. In the German S3 guideline, amitriptyline, duloxetine, and pregabalin are recommended for temporary use. The aim of this study was to cross-sectionally investigate the current practice of medication in FMS patients in Germany. We systematically interviewed 156 patients with FMS, while they were participating in a larger study. The patients had been stratified into subgroups with and without a decrease in intraepidermal nerve fiber density. The drugs most commonly used to treat FMS pain were nonsteroidal anti-inflammatory drugs (NSAIDs) (41.0% of all patients), metamizole (22.4%), and amitriptyline (12.8%). The most frequent analgesic treatment regimen was "on demand" (53.9%), during pain attacks, while 35.1% of the drugs were administered daily and the remaining in other regimens. Median pain relief as self-rated by the patients on a numerical rating scale (0-10) was 2 points for NSAIDS, 2 for metamizole, and 1 for amitriptyline. Drugs that were discontinued due to lack of efficacy rather than side effects were acetaminophen, flupirtine, and selective serotonin reuptake inhibitors. Reduction in pain severity was best achieved by NSAIDs and metamizole. Our hypothesis that a decrease in intraepidermal nerve fiber density might represent a neuropathic subtype of FMS, which would be associated with better effectiveness of drugs targeting neuropathic pain, could not be confirmed in this cohort. Many FMS patients take "on-demand" medication that is not in line with current guidelines. More randomized clinical trials are needed to assess drug effects in FMS subgroups.

Analgesic benefit of metamizole and ibuprofen vs. either medication alone: a randomized clinical trial.

BACKGROUND: Postoperative pain relief remains a key problem after surgery. Multimodal pain therapy has proven beneficial in alleviating pain to a certain extent. However, when combining non-opioids, the focus has been on NSAIDs and paracetamol, but effects of combined use are only moderate. Metamizole could be a potent adjunct, due to its preclusion in several countries, data on its combined use are sparse, despite its common use in many countries. The aim of this study was to examine whether the combination of metamizole and ibuprofen is superior in relieving postoperative pain to either drug alone. METHODS: For this randomized, placebo-controlled, cross-over study, 35 patients undergoing bilateral lower third molar extraction were randomized. Each patient received three applications of 1000 mg metamizole + 400 mg ibuprofen for surgery on one side and either 1000 mg metamizole + placebo or 400 mg ibuprofen + placebo on the other side. Pain ratings, rescue-medication (tramadol), and sleep were assessed for 18 hours. RESULTS: The combined treatment of metamizole and ibuprofen showed lower mean pain scores over 12 hours than ibuprofen (2.4±1.3 vs 3.8±1.6; P=0.005). Further, combined treatment showed lower mean pain scores over 6 hours than ibuprofen (2.0±1.2 vs. 3.1±1.6; P=0.022) or metamizole alone (2.0±1.2 vs. 3.3±1.7; P=0.015). Consumption of rescue medication was lowest in the combination-group (25% vs. 46%-metamizole; 50%-ibuprofen). The trial was stopped prematurely as the COVID-pandemic halted elective surgeries. CONCLUSIONS: Combined use enables superior pain control compared to ibuprofen after molar extraction and tends to be superior to metamizole alone. The premature study-termination may overestimate this effect.

Pharmacokinetics of metamizole (dipyrone) as an add-on in calves undergoing umbilical surgery.

This preliminary clinical investigation of the pharmacokinetic behavior of the main metamizole (dipyrone) metabolites 4-methylaminoantipyrine (4-MAA) and 4-aminoantipyrine (4-AA) in calves undergoing umbilical surgery is part of an already published main study. A single intravenous dose of metamizole was added to ketamine/xylazine/isoflurane anesthesia. Eight Simmental calves weighing 90 ± 10.8 kg and aged 47.6 ± 10.4 days received 40 mg/kg metamizole intravenously 10 minutes prior to general anesthesia. Blood samples were collected over 24 hours and analyzed for 4-MAA and 4-AA. Meloxicam was additionally given twice: 2.5 hours pre- and 20.5 hours postsurgically. The pharmacokinetic profile of 4-MAA was best fitted to a two-compartment model and was characterized by a fast distribution half-life and slow elimination half-life (t½alpha = 5.29 minutes, t½beta = 9.49 hours). The maximum concentration (Cmax 101.63 µg/mL) was detected at the first measurement time point 15 minutes after administration. In contrast, 4-AA showed fast, high and biphasic plasma peak concentration behavior in five calves (2.54-2.66 µg/mL after 15-30 minutes, and 2.10-2.14 µg/mL after 2-3.5 hours) with a t½beta of 8.87 hours, indicating a rapid distribution and subsequent redistribution from well-perfused organs. Alternatively, three calves exhibited a slower and lower monophasic plasma peak concentration (1.66 µg/mL after 6.5 hours) with a t½beta of 6.23 hours, indicating slow accumulation in the intravascular compartment. The maximum concentration and area under the plasma concentration curve (AUC) of 4-AA were lower than those of 4-MAA. This metabolic behavior supports our already published data on clinical monitoring and plasma cortisol concentrations (PCCs). Compared to those of saline controls, lower PCCs correspond to the t½alpha of 4-MAA. Data on Tmax and t½beta also match these clinical observations. However, further studies are required to assess the exact analgesic mechanism and potency of the metamizole metabolites in calves.

Stability evaluation of morphine, hydromorphone, metamizole and esketamine containing analgesic mixtures applied for patient-controlled analgesia in hospice and palliative care.

In this study, different injection solutions containing opioid and nonopioid compounds used for patient-controlled analgesia in hospice and palliative care were evaluated in terms of analyte stability. Investigated injection solutions contained different combinations of morphine, hydromorphone, metamizole and esketamine. For the practical implementation, samples from infusion pumps were daily drawn over a period of 7 days at 22 and 37°C. Quantitative measurements were performed on a high-performance liquid chromatography system with ultraviolet detection applying a validated analytical method. All compounds apart from morphine showed no evident changes in concentration. However, a significant loss of morphine was observed for injection mixtures containing both morphine and metamizole at 37°C. After 7 days, only 72% of the initially measured morphine concentration was measured in the binary and 77% in the ternary mixture. Furthermore, an additional compound was detected that could represent the morphine-metamizole-adduct, "metamorphine". Based on these results, a significantly reduced morphine concentration must be expected after only 3 days if an injection solution mixture containing both morphine and metamizole is administered to a patient at 37°C. Since the analgesic effects of morphine-metamizole adducts have not yet been thoroughly investigated, further clinical studies are necessary before accurate conclusions can be drawn in this regard.

Analysis of potential drug interactions in medical clinic sector in a Hospital of João Pessoa - PB

Abstract The objective of this study was to evaluate drug interactions based on medical records of patients hospitalized in University Hospital Lauro Wanderley (UHLW) in João Pessoa-PB, Brazil. This was a quantitative, descriptive study with a cross-sectional design. This research was conducted in the medical clinic of the above hospital by analyzing pharmaceutical intervention in medical records. The investigated samples consisted of all medical profiles with drug interaction information of patients hospitalized from June 2016 to June 2017. Most of these drug interactions were determined and classified by Micromedex® Solutions database. This research was approved by the Ethics Committee in Institutional Human Research, protocol number 2.460.206. In total, 331 drug interactions were found in 131 medical profiles. Dipyrone, enoxaparin, sertraline, ondansetron, quetiapine, tramadol, bromopride, amitriptyline, and simvastatin were medications that showed highest interactions. According to Anatomical Therapy Classification (ATC), drugs that act on the central nervous system result in more interactions. The most prevalent interaction was between dipyrone and enoxaparin. Some limitations of this study are the lack of notifications and data on drug interactions.