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.

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

Introducción: En la literatura existen pocas referencias que comparen las distintas alternativas disponibles para controlar el dolor enel postoperatorio inmediato de la apendicitis aguda pediátrica (AAP).Material y métodos: Comparación prospectiva del perfil anal-gésico y emético del ibuprofeno y el metamizol intravenosos en elpostoperatorio inmediato de la AAP, para lo cual se recurre a unamuestra de pacientes operados en 2021 en nuestro centro. Los participantes fueron reclutados a su llegada a Urgencias, obteniéndoseconfirmación histopatológica del diagnóstico en todos ellos. La evaluación del dolor se llevó a cabo cada 8 horas tras la cirugía medianteescalas analógicas visuales validadas, con valoraciones entre los 0 ylos 10 puntos. Se realizó un ANOVA de las medidas repetidas entrelos dos grupos para comparar la evolución del dolor en las 48 horasposteriores 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 conmetamizol (grupo 2). No se hallaron diferencias significativas en lo querespecta 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). Unavez realizado el ajuste correspondiente a la terapia de fluidos recibida,los niños del grupo metamizol tuvieron significativamente más episodioseméticos y necesitaron significativamente más dosis de ondansetrón.Conclusiones: En nuestra cohorte, el ibuprofeno tuvo una eficaciaanalgésica similar y un mejor perfil emético que el metamizol en elpostoperatorio inmediato de la AAP. Se hacen necesarios nuevos estudiosprospectivos, adecuadamente controlados y con mayor tamaño muestralque validen estos hallazgos.(AU)

Background: Literature comparing different alternatives for paincontrol in the immediate postoperative period of pediatric acute appendicitis (PAA) is scarce.Materials and methods: We prospectively compared the analgesicand emetogenic profile of intravenous ibuprofen and metamizole in theimmediate postoperative period of PAA. For this purpose, we used asample of patients operated on in 2021 in our center. Participants wererecruited on arrival at the Emergency Department and histopathologi-cal confirmation of the diagnosis was obtained in all of them. Pain wasevaluated every 8 hours after the surgery with validated visual analogscales ranging from 0 to 10 points. Repeated measures ANOVA wasused to compare the evolution of pain in the 48 hours after surgerybetween the two groups. Results: The sample included 95 patients (65% males) with a meanage of 9.7 years (sd: 3.14). 41 patients were treated with Ibuprofen(group 1) and 54 with metamizole (group 2). No significant differ-ences were found in the level of pain either in the comparisons of pointmeasurements or in its evolution in the 48 hours after surgery (p= 0.58).After adjusting for the received fluid therapy, children in the metamizolegroup had significantly more emetic episodes and needed significantlymore doses of ondansetron. Conclusions: In our cohort, ibuprofen had a similar analgesic ef-ficacy and a better emetogenic profile than metamizole in the immediatepostoperative period of PAA. Future prospective, adequately controlledstudies with larger sample sizes are needed to validate these findings.(AU)

Case series: Heinz body formation in 13 multimorbid dogs following metamizole administration.

Background: Heinz Body (HB) anemia is a result of oxidative damage and is an uncommon condition in dogs relative to cats. In this retrospective case series, clinical features, laboratory values, concurrent diseases, and outcomes of 13 multimorbid dogs that developed HBs after receiving metamizole are reported. Case description: Of the 13 dogs in this case series that developed HBs, 10 were older and multimorbid, but the only feature that all the dogs had in common was receiving metamizole. HBs were detected in 7 out of 13 dogs within a few days (3-10 days) after starting metamizole treatment. The metamizole dose was 38-159 mg/kg/day. The highest percentage of HBs detected was 28-95% (mean, 46%). There was no correlation between the percentage of HBs and the daily dose of metamizole. All but 1 dog had mild-to-severe anemia at the time of the highest HB appearance. The number of HBs did not correlate with the hematocrit at that time. In 8/12 dogs, no stress leukogram was present. Approximately half of the dogs with HBs also had evidence of gastrointestinal hemorrhage, which could have masked additional oxidative damage. Conclusion: In multimorbid dogs that develop regenerative anemia after receiving metamizole, hemolysis due to HB development caused by oxidative damage should be considered as an important differential diagnosis.

Analysis of umbilical cord tissue as an indicator of in utero exposure to toxic adulterating substances.

In utero drug exposure is a significant public health threat to the well-being and normal development of the neonate. Recently, testing of umbilical cord tissue (UCT) has been employed to measure illicit drug exposure, as drugs used by the mother during the third trimester may be retained in the UCT. Focus has also been given to potential adverse health effects among drug users, resulting from exposure to pharmacologically active adulterants and cutting agents in the street drug supply. The in utero effects of these substances have not been well studied in humans, nor has their presence been demonstrated as a means for assessing adverse health effects in the neonate. Here, we describe the application of a novel test method to analyze UCT for the presence of more than 20 common adulterating/cutting substances via LC/Q-TOF. In total, 300 de-identified UCT samples were analyzed-all had previously tested positive for cocaine or opiates. Generally, the positivity rates of individual compounds were similar between the Cocaine and Opiates Subgroups, apart from levamisole, xylazine, dipyrone (metabolites), and promethazine. Many of the adulterants used in the street drug supply do have legitimate medicinal/therapeutic uses, including several of the compounds most frequently detected in this study. Caffeine and lidocaine were the most frequently identified compounds both individually (>70% each) and in combination with each other. Alternatively, levamisole, an adulterant with no legitimate therapeutic use, was present in 12% of cases. Importantly, this data demonstrates that the detection of traditional drugs of abuse may serve as indicators of potential in utero exposure to toxic adulterating substances during gestation. While there is cause for concern with respect to any unintentional drug exposure, illicit drug use during pregnancy, including uncontrolled dosing, poly-adulterant consumption, and the interactions of these drug mixtures, produces a significant public health threat to the neonate which warrants further study.

Time course of CYP3A activity during and after metamizole (dipyrone) in healthy volunteers.

AIMS: In patients of all ages, metamizole is a frequently used analgesic. Recently, metamizole has been identified as an inducer of, among others, cytochrome P450 (CYP) 3A activity, but the time course of this interaction has not been evaluated. METHODS: Using repeated oral microdoses (30 µg) of the CYP3A index substrate midazolam, we assessed changes in midazolam pharmacokinetics (area under the concentration-time curve from 2-4 h: AUC2-4 and estimated partial metabolic clearance: eClmet ) before, at steady-state, and after discontinuation of 3 × 1000 mg metamizole/day orally for 8 days. RESULTS: Significant changes in pharmacokinetic parameters were detected already 3 days after start of metamizole treatment. At the steady-state of enzyme induction, the geometric mean ratio of midazolam AUC2-4 was substantially reduced to 0.18 (90% confidence interval: 0.14-0.24) with a corresponding 5.43-fold (4.15-7.10) increase of eClmet . After discontinuation of metamizole, the changes slowly recovered, but were still significant at the end of the observation period on the fifth day after discontinuation of metamizole therapy (AUC2-4 reduced to 0.50 [0.41-0.63] and eClmet 1.99-fold increased [1.60-2.47, P < 0.05]). CONCLUSION: Metamizole acts as a strong inducer of CYP3A already few days after start of metamizole administration and, thus, should be avoided in patients using drugs with narrow therapeutic index and major clearance via CYP3A. If their administration is essential, close monitoring and dose adjustment of comedication should be performed as early as the first week after the initiation and after discontinuation of metamizole therapy.

A Case Report on Metamizole-Induced Agranulocytosis: Is the Benefit Worth the Risk?

Metamizole is a drug with analgesic and antipyretic properties widely available in Portugal. Its use is highly controversial because of the risk of agranulocytosis, a rare but serious adverse event. A 70-year-old female patient with a recent history of treatment with metamizole for post-surgery fever and pain presented to the ED with sustained fever, diarrhea, and painful mouth ulcers. Laboratory tests revealed agranulocytosis. The patient was placed under protective isolation and started treatment with granulocyte-colony stimulating factor (G-CSF) and empiric antibiotic therapy with piperacillin/tazobactam and vancomycin for neutropenic fever. After an extensive workup, no source of infection was identified. During hospitalization, infectious and neoplastic causes of agranulocytosis were investigated, but the results were negative. Metamizole-induced agranulocytosis was suspected. The patient completed a total of three days of G-CSF and eight days of empiric antibiotic therapy with sustained clinical improvement. She was discharged completely asymptomatic and remained clinically stable during follow-up without a resurgence of agranulocytosis. This case report is intended to increase awareness of metamizole-induced agranulocytosis. While this is a well-known side effect, it is also often overlooked. It is paramount that both physicians and patients know how to correctly manage metamizole to prevent and promptly treat agranulocytosis.

Assessment of local pain and analgesia in envenoming by wandering spiders (Phoneutria spp.).

Phoneutrism (bites by wandering spiders of the genus Phoneutria) frequently results in local pain. We describe a retrospective cohort study of a case series of phoneutrism admitted to our Emergency Department (ED), in which we used the Numeric Pain Rating Scale (NPRS 0-10) to assess the intensity of local pain upon admission, and recorded the analgesic measures used to control this pain. Other criteria for inclusion were: (1) An age ≥8 years, (2) Treatment exclusively at our ED, and (3) Visualization or photographing the spider at the time of the bite and/or bringing the spider for identification. The patients were classified into three groups based on the intensity of pain at admission: group 1 - mild or no pain (NPRS: 0-3), group 2 - moderate pain (NPRS: 4-6), and group 3 - intense or severe pain (NPRS: 7-10). Fifty-two patients fulfilled the inclusion criteria (n = 11, 14 and 27 in groups 1, 2, and 3, respectively), with a median age of 37 years. The median NPRS upon admission was 7 (interquartile range: 5-8). In patients with an NPRS <7 (groups 1 and 2), only dipyrone was used to alleviate the pain, with six cases in group 1 requiring no analgesia. Most of the cases in group 3 (19/27) were treated with a local anesthetic infiltration (2% lidocaine), in association with analgesics given i.v. in 16 cases (dipyrone, 14; tramadol, 2); additional analgesic treatment was required in seven cases, six of which were treated with tramadol i.v. The median time spent in the ED was 18, 58 and 120 min for groups 1, 2 and 3, respectively. These findings show that most cases of envenoming by Phoneturia spp. involved intense local pain (NPRS ≥7), with local anesthetics being used only in these cases, often in association with dipyrone i.v.

Real-world evidence for beneficial effects of dipyrone in 4,278 patients with pulmonary hypertension - Analysis of the risk of ventilation, hospitalization, and agranulocytosis.

INTRODUCTION: Dipyrone has been used as an analgesic for a century, but recently was proposed as a novel therapeutic strategy for the prevention and therapy of pulmonary hypertension (PH). The aim of this study was to analyze whether the risk for ventilation procedures and hospitalization was lower among patients with PH who used dipyrone compared to subjects who did not use dipyrone. MATERIALS AND METHODS: Initially, patients with PH were retrieved from the TriNetX database, whereby subjects who used dipyrone were assigned to cohort I, and cohort II was formed by those individuals who did not use dipyrone. Both cohorts were matched for several variables. The outcomes were requirement for ventilation procedures and hospital admission, whereby the time window to record events was 5 years after diagnosis of PH. Subsequently, risk analysis was carried out, and risk ratio (RR) and odds ratio (OR) were calculated. In addition, the risk of agranulocytosis was determined for both cohorts. RESULTS: Out of 741,875 individuals diagnosed with PH 4,282 and 737,593 patients were assigned to the cohorts I and II. After matching, each cohort accounted for 4,278 individuals. Among the cohorts I and II 10 and 187 individuals required ventilation procedures. The according risks of 0.2% vs. 4.4% were significantly different (p < 0.0001; Log-Rank test). RR and OR were 0.053 and 0.051. Within the cohorts I and II 10 and 1,195 subjects required hospital admission. The risks of hospitalization of 0,4% vs. 27.9% differed significantly (p < 0.0001). RR and OR were 0.016 and 0.012. Among the cohorts I and II 47 and 66 individuals were diagnosed with agranulocytosis, whereby no significance was found (p > 0.05). CONCLUSIONS: The risk for ventilation measures and hospitalization among patients with PH was found to be significantly lower when dipyrone was used. Even though the underlying mechanisms remain unknown to date, they are supposedly mediated by an active metabolite of dipyrone. The obtained results appear to be promising for patients suffering from PH. Hence, the present study may encourage further research.

Pharmacokinetic profiles of the two major active metabolites of metamizole, 4-methylaminoantipyrine (MAA) and 4-aminoantipyrine (AA), after intravenous injection in cats.

This study aimed to determine the pharmacokinetic profile of two active metabolites of metamizole (dipyrone), N-methyl-4-aminoanthypyrine (MAA) and 4-aminoanthypyrine (AA), after intravenous administration in cats. Eight healthy mixed-breed cats were intravenously administered metamizole (25 mg/kg). Blood samples were collected at predetermined time points for up to 48 h after administration. Information on behavioral changes in the animals and adverse effects was collected. Plasma aliquots were processed and analyzed using the ultra-performance liquid chromatography tandem mass spectrometry technique. A validated UPLC-MS/MS method was used to characterize the pharmacokinetics of MAA and AA. Salivation was identified as an adverse clinical sign. The mean maximal plasma concentrations of MAA and AA were 29.31 ± 24.57 µg/mL and 1.69 ± 0.36 µg/mL, with half-lives of around 4.98 and 14 h, respectively. The area under the plasma concentration curve values were 28.54 ± 11.33 and 49.54 ± 11.38 h*µg/mL for MAA and AA, respectively. The plasma concentration of MAA was detectable for up to 24 h and was smaller than AA. AA was detectable for >48 h. Results suggest that metamizole is converted into active metabolites in cats. Further PK/PD and safety studies should be performed before defining the dose or administration intervals for clinical use.

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.

Perfil prescriptivo de corticoides en el servicio de urgencias del Hospital Odontológico de la ciudad de Formosa, Argentina / Prescriptive Profile of Corticoids in the Emergency Department of the Dental Hospital of the City of Formosa, Argentina

Objetivo: identificar el perfil prescriptivo de corticoides en pacientes que asistieron al Servicio de Urgencias del Hospital Odontológico de la ciudad de Formosa, Argentina. Métodos: se realizó un estudio transversal, observacional y descriptivo, se analizaron las prescripciones de corticoides realizadas por odontólogos que atendieron en el Servicio de Urgencias del Hospital Odontológico de la ciudad de Formosa desde marzo 2019 a febrero 2020. Las variables de estudio fueron: características demográficas del paciente, diagnóstico clínico odontológico, corticoide prescrito, dosis y forma farmacéutica. Resultados: de un total de 9.635 historias clínicas, se observaron 3.244 prescripciones de corticoides (33,6%). De acuerdo a los corticoides prescritos, se halló a la dexametasona para vía intramuscular y además se utilizó dexametasona en tratamientos combinados con dipirona para vía intramuscular e ibuprofeno para vía oral. Los diagnósticos relacionados con prescripción de estos medicamentos fueron: pulpitis, periodontitis apical aguda, flemón/absceso, entre otras. De acuerdo al valor intrínseco terapéutico potencial, los fármacos prescritos en el hospital odontológico son de valor elevado, esto significa que demostraron eficacia para el tratamiento, el diagnóstico o la prevención de enfermedades del ser humano. Conclusiones: el estudio de la utilización de medicamentos en el Hospital Odontológico de la ciudad de Formosa permitió observar situaciones donde los corticoides no están indicados. Además, se señala la prescripción excesiva de la vía intramuscular. A partir de los resultados obtenidos es necesario realizar una retroalimentación a los prescriptores, por lo que se sugieren intervenciones para elaborar propuestas de solución a los problemas identificados y formular políticas de medicamentos.

Objective: to identify the prescriptive profile of corticosteroids in patients who were treated at the Emergency Service of the Dental Hospital of the City of Formosa, Argentina. Methods: a cross-sectional, observational, and descriptive study was carried out, and corticosteroid prescriptions made by dentists who attended the Emergency Service of the Dental Hospital of the City of Formosa, from March 2019 to February 2020 were analyzed. The study variables were: demographic characteristics of the patient, dental clinical diagnosis, corticosteroid prescribed, dose, and pharmaceutical form. Results: Of 9,635 medical records, 3,244 corticosteroid prescriptions (33.6%) were observed. According to the prescribed corticosteroids, dexamethasone was found for the intramuscular route, and dexamethasone was also used in combined treatments with dipyrone for the intramuscular route and ibuprofen for the oral route. The diagnoses related to the prescription of these medications were: pulpitis, acute apical periodontitis, phlegmon/abscess, trauma, pericoronitis, hypersensitivity and alveolitis. According to the potential therapeutic intrinsic value, the drugs prescribed in the dental hospital are of high value, which means that they have demonstrated efficacy for the treatment, diagnosis or prevention of diseases that affect humans. Conclusions: the study of the use of drugs in the Dental Hospital of the City of Formosa allowed us to observe situations where corticosteroids are not indicated. In addition, the excessive prescription of the intramuscular route is pointed out. Based on the results obtained, it is necessary to provide feedback to the prescribers, so it is suggested to continue with different interventions to develop proposals for solutions to the identified problems and formulate drug policies.

2-Arylpropionic Acid Pyrazolamides as Cannabinoid CB2 Receptor Inverse Agonists Endowed with Anti-Inflammatory Properties.

Among the most recent proposals regarding the mechanism of action of dipyrone, the modulation of cannabinoid receptors CB1 and CB2 appears to be a promising hypothesis. In this context, the present work describes a series of five novel pyrazolamides (7-11) designed as molecular hybrids of dipyrone metabolites and NSAIDs, such as ibuprofen and flurbiprofen. Target compounds were obtained in good overall yields (50-80%) by classical amide coupling between 4-aminoantipyrine and arylacetic or arylpropionic acids, followed in some cases by N-methylation of the amide group. The compounds presented good physicochemical properties in addition to stability to chemical (pH 2 and 7.4) and enzymatic (plasma esterases) hydrolysis and showed medium to high gastrointestinal and BBB permeabilities in the PAMPA assay. When subjected to functional testing on CB1- or CB2-transfected cells, compounds demonstrated an inverse agonist profile on CB2 receptors and the further characterization of compound LASSBio-2265 (11) revealed moderate binding affinity to CB2 receptor (Ki = 16 µM) with an EC50 = 0.36 µM (Emax = 63%). LASSBio-2265 (11) (at 1, 3, and 10 mg/kg p.o.) was investigated in the formalin test in mice and a remarkable analgesic activity in the late inflammatory phase was observed, suggesting it could be promising for the treatment of pain syndromes associated with chronic inflammatory diseases.

Design, synthesis and in vivo evaluation of 1,4-dioxo-2-butenyl aryl amine derivatives as a promising anti-inflammatory drug prototype.

Inflammation is a natural response of the organism to an infection, trauma, or cellular stress. Pain is the first symptom of acute and chronic inflammation. The standard class of medication to treat inflammatory pain is the nonsteroidal anti-inflammatory drug (NSAID). These drugs are associated with severe side effects such as gastric ulcers, gastritis, or internal bleeding. One of NSAIDs, Dipyrone® (metamizole) is largely used in many European and South American countries despite its dubious effectivity and its withdrawal from the market of several countries. Here, aiming to identify a new anti-inflammatory drug prototype based on Dipyrone® structure, a set of 27 molecules were virtually screened, and 4 compounds containing the active metabolite 4-aminoantipyrine and 1,4-dioxo-2-butenyl fragment were selected for docking, synthesis, and biological evaluation. The selection was based on the number of H-bonds and π- π stacking interactions between the inhibitor and the amino acids within the binding site of the enzyme. Carrageenan-induced paw edema, acetic acid-induced writhing, and formalin assays were used to evaluate inflammation and pain response. The selected compounds 1-4 inhibited the involvement of biogenic amines in the formation of paw edema. Compounds 1-4 also reduced pain in the inflammatory response phase. It has to be noted that 4-AA may cause agranulocytosis, which should be borne in mind when developing drug candidates of similar structure. Our new drug prototypes based on 4-aminoantipyrine and 1,4-dioxo-2-butenyl moieties open a gate for developing a prototype of nonsteroidal anti-inflammatory drugs.

Simultaneous determination of ergotamine, caffeine and dipyrone in their ternary mixture by applying double divisor and first derivative ratio spectra methods.

Two validated methods namely, double divisor ratio spectra derivative spectroscopy and derivative ratio spectroscopy with zero crossing point were applied to assay a ternary mixture of ergotamine tartrate (EGT), caffeine (CAF) and dipyrone sodium (DIP) without any additional separation steps. The linearity ranges using both methods were (1.0µg/mL-70.0µg/mL), (60.0µg/mL-100.0µg/mL) and (100.0µg/mL-300.0µg/mL) for EGT, CAF and DIP respectively. Double divisor ratio spectroscopy (method A) depends on dividing the different peak responses of EGT on (summation of peaks responses of CAF and DIP each of 10.0µg/mL concentration) at λ max=342nm, 310nm and 315nm for EGT, CAF and DIP respectively. Derivative ratio spectroscopy with zero crossing point (method B) depends on dividing the peak responses of two drugs (EGT and CAF) on (10.0µg/mL of DIP) and dividing the peak response of DIP on peak response of (10.0µg/mL of EGT). The detection limits of the studied drugs applying method A were (3.54, 12.96 and 8.748µg/mL), with quantitation limits of (10.73, 39.28 and 26.51µg/mL) for EGT, CAF and DIP respectively. Regarding method B, the limits of detection and quantitation for EGT were 0.604µg/mL and 1.829µg/mL respectively: with corresponding values of 19.44µg/mL and 58.92µg/mL for CAF and 20.44µg/mL and 61.9µg/mL for DIP. The obtained results were compared to those obtained by published methods and were found to be in accordance.

Acute Kidney Injury associated with "Triple whammy" combination: a protocol for a systematic review.

Background: "Triple whammy" (TW) refers to the simultaneous use of diuretics, renin-angiotensin-aldosterone system inhibitors and nonsteroidal anti-inflammatory drugs (NSAIDs). To date, the risk of developing acute kidney injury (AKI) associated to this combination has not been deeply investigated. The objectives are to analyze the incidence of AKI associated to the exposure to "triple whammy" including all NSAIDs versus non-exposure to this combination. Secondarily, the risk of hospitalization, severe adverse events, requirement of renal replacement therapy and mortality will be assessed. Also, the incidence of AKI associated to the exposure to "triple whammy" versus non-exposure will be analyzed, including only metamizole as NSAID.   Methods: A systematic literature search of intervention studies and analytical observational studies will be conducted in the Cochrane Library, Medline and EMBASE, among others. AKI 12 months after the last prescription of the triple combination will be the main outcome. Relative frequencies, risk of bias and certainty of evidence will be analyzed. Additionally, sensitivity and subgroup analyses will be performed.   Results: Once this systematic review has been completed, the results are expected to provide an estimate of the risk associated with this triple combination and the renal variables, in addition to new guidance on the renal treatment of patients potentially receiving triple therapy.  Conclusions: This is intended to be the first systematic review of observational studies to analyse TW combination and AKI's risk based on well-validated epidemiological databases exploring drug safety issues.

Real world evidence of the use of metamizole (dipyrone) by the Brazilian population. A retrospective cohort with over 380,000 patients

ABSTRACT Objective To determine under which health conditions metamizole (dipyrone) is used as a single drug or as fixed-dose combination. Methods Two retrospective cohorts of Brazilian patients treated with metamizole between January 2015 and December 2017 were analyzed: a metamizole-based cohort (Cohort 1) and a symptoms-based cohort (Cohort 2). Anonymized patient data was obtained from Amil Clinical Data Warehouse. The number of patients with symptoms was described by age and sex. Results The sample size of the two cohorts consisted of 384,668 patients. In patients using metamizole (Cohort 1), the most common reason for medication was the treatment of some form of pain (81%), followed by fever (19%). Headache was the most common (19%) specified pain class, followed by sore throat (8%), muscular pain (6%), and abdominal pain (5%). In adult patients (n=276,279; 71.8%), metamizole was used as a monotherapy or associated with another drug, for any sort of pain, in over 88% of the patients. General pain was the main reason for metamizole use in children (61%). Conclusion Real world evidence to evaluate Brazilian patients' therapeutic options is unusual and yet to be more explored using digital tools enabling better data registration. The present study confirmed that metamizole is widely used as a non-anti-inflammatory drug, and also showed the management of pain and fever as the most frequent indications in all age groups studied. Registry in Clinical Trials Database: REBEC Database: 10507

Excess Mortality in Aspirin and Dipyrone (Metamizole) Co-Medicated in Patients With Cardiovascular Disease: A Nationwide Study.

Background Pain is a major issue in our aging society. Dipyrone (metamizole) is one of the most frequently used analgesics. Additionally, it has been shown to impair pharmacodynamic response to aspirin as measured by platelet function tests. However, it is not known how this laboratory effect translates to clinical outcome. Methods and Results We conducted a nationwide analysis of a health insurance database in Germany comprising 9.2 million patients. All patients with a cardiovascular event in 2014 and subsequent secondary prevention with aspirin were followed up for 36 months. Inverse probability of treatment weighting analysis was conducted to investigate the rate of mortality, myocardial infarction, and stroke/transient ischemic attack between patients on aspirin-dipyrone co-medication compared with aspirin-alone medication. Permanent aspirin-alone medication was given to 26,200 patients, and 5946 patients received aspirin-dipyrone co-medication. In the inverse probability of treatment weighted sample, excess mortality in aspirin-dipyrone co-medicated patients was observed (15.6% in aspirin-only group versus 24.4% in the co-medicated group, hazard ratio [HR], 1.66 [95% CI, 1.56-1.76], P<0.0001). Myocardial infarction and stroke/transient ischemic attack were increased as well (myocardial infarction: 1370 [5.2%] versus 355 [5.9%] in aspirin-only and co-medicated groups, respectively; HR, 1.18 [95% CI, 1.05-1.32]; P=0.0066, relative risk [RR], 1.14; number needed to harm, 140. Stroke/transient ischemic attack, 1901 [7.3%] versus 506 [8.5%] in aspirin-only and co-medicated groups, respectively; HR, 1.22 [95% CI, 1.11-1.35]; P<0.0001, RR, 1.17, number needed to harm, 82). Conclusions In this observational, nationwide analysis, aspirin and dipyrone co-medication was associated with excess mortality. This was in part driven by ischemic events (myocardial infarction and stroke), which occurred more frequently in co-medicated patients as well. Hence, dipyrone should be used with caution in aspirin-treated patients for secondary prevention.

[Perioperative analgesia with nonopioid analgesics : Joint interdisciplinary consensus-based recommendations of the German Pain Society, the German Society of Anaesthesiology and Intensive Care Medicine and the German Society of Surgery]. / Perioperative Schmerztherapie mit Nichtopioidanalgetika : Gemeinsame interdisziplinäre Empfehlung der Deutschen Schmerzgesellschaft, der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin und der Deutschen Gesellschaft für Chirurgie.

BACKGROUND: Nonopioid analgesics are frequently used for perioperative analgesia; however, insufficient research is available on several practical issues. Often hospitals have no strategy for how to proceed, e.g., for informing patients or for the timing of perioperative administration of nonopioid analgesics. METHODS: An expert panel representing the German national societies of pain, anaesthesiology and intensive care medicine and surgery developed recommendations for the perioperative use of nonopioid analgesics within a formal, structured consensus process. RESULTS: The panel agreed that nonopioid analgesics shall be part of a multimodal analgesia concept and that patients have to be informed preoperatively about possible complications and alternative treatment options. Patients' history of pain and analgesic intake shall be evaluated. Patients at risk of severe postoperative pain and possible chronification of postsurgical pain shall be identified. Depending on the duration of surgery, nonopioid analgesics can already be administered preoperatively or intraoperatively so that plasma concentrations are sufficient after emergence from anesthesia. Nonopioid analgesics or combinations of analgesics shall be administered for a limited time only. An interdisciplinary written standard of care, comprising the nonopioid analgesic of choice, possible alternatives, adequate dosing and timing of administration as well as surgery-specific policies, have to be agreed upon by all departments involved. At discharge, the patient's physician shall be informed of analgesics given and those necessary after discharge. Patients shall be informed of possible side effects and symptoms and timely discontinuation of analgesic drugs. CONCLUSION: The use of nonopioid analgesics as part of a perioperative multimodal concept should be approved and established as an interdisciplinary and interprofessional concept for the adequate treatment of postoperative pain.

Pharmacokinetics of dipyrone in horses: A multi-dose, dose escalation study.

Dipyrone is a non-opioid, nonsteroidal anti-inflammatory drug with antipyretic and analgesic properties commonly used in horses. Dipyrone is rapidly hydrolyzed to the primary active metabolite 4-methylaminoantipyrine (4-MAA). The purpose of this study was to determine the pharmacokinetic profile of 4-MAA following repeated and escalating doses of intravenously administered dipyrone. Twenty-six horses were randomly allocated to five treatment groups (one placebo group and four dipyrone groups [30 mg/kg q8h, 30 mg/kg q12h, 60 mg/kg q8h, and 90 mg/kg q12h]) and treated for nine consecutive days. Blood was collected at predetermined timepoints, and plasma was analyzed for 4-MAA concentrations with a validated LC/MS/MS method. Following a single dose, there was a linear correlation to the maximum concentration (Cmax ) achieved. There was a disproportionate increase in the minimum concentration (Cmin ) of 4-MAA with accumulation occurring at higher doses or more frequent dosing intervals. Significant differences were noted in 4-MAA Cmax , half-life, and area under the curve during the dosing interval (AUCtau ) when dipyrone was administered at 30 mg/kg q12h versus q8h. Adverse effects attributed to drug administration were not noted.

The role of endocannabinoid system and TRPV1 receptors in the antidepressant and anxiolytic effects of dipyrone in chronic unpredictable mild stress in mice.

Although dipyrone is a widely used analgesic and antipyretic, its mechanism of action is not fully clarified. Recent studies have drawn attention to its central effects and its relationship with the endocannabinoid system. The endocannabinoid system plays important roles in processes such as anxiety, depression, fear, and learning-memory. In this study, we aimed to investigate whether endocannabinoid levels change in the amygdala in chronic unpredictable mild stress model in mice and whether cannabinoid and TRPV1 receptors mediate antidepressant and anxiolytic effects of dipyrone. Mice were submitted to chronic unpredictable mild stress protocol of 6-weeks, then behavioral test were performed. In the first part of the study, dipyrone was injected at doses of 150, 300, and 600 mg/kg (i.p.) during behavioral tests. In the second part, the CB1 antagonist AM 251 (1 mg/kg, i.p.), the CB2 antagonist AM630 (1 mg/kg, i.p.), and the TRPV1 antagonist capsazepine (3 mg/kg, i.p.) were administered alone or in combination with 300 mg/kg dipyrone to observe if these receptors mediate dipyrone effects. Endocannabinoid and N-acylethanolamines levels were measured by LC-MS/MS in amygdala. Our results showed that there were no changes in AEA, 2-AG, PEA, OAE levels in the amygdala in mice exposed to chronic unpredictable mild stress model; dipyrone exerted antidepressant and anxiolytic effects at doses of 300 and 600 mg/kg; its anxiolytic effect appears to be mediated via CB1 receptors, whereas TRPV1 receptors seems to mediate its antidepressant action.