Stability of individualized neonatal parenteral nutrition admixtures with fish oil and high calcium content.

Introduction: Introduction: the stability of total parenteral nutrition admixtures for neonates (TPNAn) has been questioned in relation to the interaction between calcium and fish oil emulsions. Aim: the aim of this study was to check the stability (particle size < 1 µm) of different individualized TPNAn prepared with fish-oil emulsion and containing calcium at concentrations ranging from 10 to 20 mmol/L. Methods: admixtures analyzed: twelve different formulations with SMOFlipid® 20 % (conserved for 24 h and for 96 h), three formulations with Lipoplus® 20 % (conserved for 96 h) and three formulations with SMOFlipid® 20 % with Multi-12K1® Pediatric (conserved for 96 h). Two bags were compounded for each formulation and conservation period. Measurements on each admixture bag: particle standardized diameter by laser diffraction technique and pH by a calibrated pH-meter. Data analysis with mixed linear regression models. Results: maximum particle size was < 0.8 µm for all investigated admixtures. Lipid concentration of 5 g/L and sodium and potassium concentration of 100 mmol/L slightly increased the proportion of particles > 0.6 µm. Ninety six hours storage also increased the percentage of particles > 0.6 µm (+0.143 ± 0.07; p = 0.038) but did not influence other parameters. No association with calcium composition was observed. Amino acid content was inversely correlated with pH (-0.83; p < 0.0001). Conclusions: the studied individualized parenteral nutrition admixtures for newborns that contain fish oil emulsions and meet cation requirements are stable for at least 96 hours.

Introducción: Introducción: existe controversia sobre la estabilidad de las mezclas de nutrición parenteral total para recién nacidos (TPNAn) con emulsiones de omega-3 y alto contenido en calcio. Objetivo: estudiar la estabilidad (tamaño de partículas < 1 µm) de diferentes TPNAn individualizadas preparados con una emulsión lipídica que contiene w3 y concentraciones de calcio entre 10 y 20 mmol/L. Métodos: se analizaron doce formulaciones diferentes con SMOFlipid® 20 % (conservadas durante 24 h y por 96 h), tres formulaciones con Lipoplus® 20 % (conservadas durante 96 h) y tres formulaciones con SMOFlipid® 20 % con Multi-12K1® Pediatric (conservadas durante 96 h). Se prepararon dos bolsas por cada formulación y período de conservación. Se midieron el diámetro de partícula estandarizado mediante técnica de difracción láser y el pH con un pH-metro calibrado. Análisis de datos con modelos de regresión lineal mixta. Resultados: el tamaño máximo de partícula fue < 0,8 µm para todas las mezclas investigadas. La concentración de lípidos de 5 g/L y la concentración de sodio y potasio de 100 mmol/L aumentaron ligeramente la proporción de partículas > 0,6 µm. El almacenamiento de noventa y seis horas también aumentó el porcentaje de partículas > 0,6 µm (+0,143 ± 0,07; p = 0,038) pero no influyó en otros parámetros. No se observó asociación con la concentración de calcio. El contenido de aminoácidos se correlacionó inversamente con el pH (-0,83; p < 0,0001). Conclusiones: las TPNAn individualizadas estudiadas con emulsiones de omega-3 que incluyen los requerimientos de cationes son estables durante al menos 96 horas.

[Translated article] Influence of augmented renal clearance in the lower incidence of linezolid-related haematological toxicity.

OBJECTIVES: Linezolid is an oxazolidin commonly related to the development of haematological toxicity, being renal clearance the major factor involved in the drug clearance. The aim of this study is to evaluate the influence of increased filtration rates in the incidence of linezolid-induced haematological toxicity by comparing augmented renal clearance (ARC) patients versus normal renal function patients. MATERIAL AND METHODS: A retrospective, observational study was conducted on hospitalized patients treated with linezolid for 5 days or more during 2014-2019 period. Patients with a filtration rate of ≥130 mL/min versus reference patients (60-90 mL/min) were compared. Haematological toxicity was defined as a decrease of 25% in platelets, of 25% in haemoglobin, and/or 50% in neutrophils from baseline. Toxicity relevance was classified according to Common Terminology Criteria for Adverse Events v5. Incidence of haematological toxicity between groups was studied by chi-square and Fisher test. Furthermore, percentage diminution of all 3 parameters was calculated and compared by Mann-Whitney test and treatment interruption and transfusion requirements were registered. RESULTS: 30 ARC patients and 38 reference patients were included. Haematological toxicity was observed in 16.66% of ARC patients vs 44.74% of reference patients (P=.014); thrombocytopenia in 13.33% vs 36.84% (P=.051), anaemia in 3.3% vs 10.52% (P=.374) and neutropenia in 10% vs 23.68% (P=.204). Median percentage of platelets decrease in ARC patients was -10.36 (-193.33-62.03) vs 2.68 (-163.16-82.71) in reference patients (P=.333), while haemoglobin decrease was 2.50 (-12.12-25.93) vs 9.09 (-17.72-30.63) (P=.047) and neutrophils decrease was 9.14 (-73.91-76.47) vs 27.33 (-86.66-90.90) (P=.093). 10.5% of normal renal function patients reported at least 1 adverse event grade 3 or superior while 2.6% of them interrupted treatment and 5.2% had transfusion requirements. No major events or interruptions were reported in ARC patients. CONCLUSION: Our findings suggest a lower incidence and clinical relevance of haematological toxicity in augmented renal clearance patients. Thrombocytopenia was the major event in both populations. This might be related to a lower exposure to the drug due to the higher clearance and likely lower therapeutic efficiency. These results suggest a potential benefit of therapeutic drug monitoring on high risk patients.

Influencia de la hiperfiltración glomerular en la menor toxicidad hematológica inducida por linezolid / Influence of augmented renal clearance on the lower incidence of linezolid-related hematological toxicity

Objetivos linezolid es una oxazolidina frecuentemente implicada en el desarrollo de toxicidad hematológica, siendo el aclaramiento renal el mecanismo mayoritario en su eliminación. Se evaluó la influencia de la hiperfiltración glomerular en la toxicidad hematológica inducida por linezolid en pacientes con aclaramiento incrementado frente a pacientes con función renal normal. Material y métodos se diseñó un estudio observacional y retrospectivo en pacientes hospitalizados, tratados al menos 5 días con linezolid entre 2014 y 2019. Se compararon pacientes con aclaramiento de creatinina incrementado (≥130 mL/min) y normal (60–90 mL/min). Se definió la toxicidad hematológica como el descenso en plaquetas y hemoglobina del 25% y en neutrófilos del 50% frente a los valores basales. Se clasificó el grado de toxicidad según Common Terminology Criteria for Adverse Events v5 y se comparó la incidencia entre ambos grupos mediante Chi-cuadrado y Fisher. Así mismo, se calculó el porcentaje de disminución de los 3 parámetros y su asociación mediante el test de Mann–Whitney y se registraron las interrupciones y transfusiones asociadas.Resultados se evaluaron 30 pacientes hiperfiltradores y 38 normofiltradores. El 16,66% de hiperfiltradores presentó toxicidad hematológica frente al 44,74% (p = 0,014). La trombocitopenia fue del 13,33 vs. 36,84% (p = 0,051), la anemia del 3,3 vs. 10,52% (p = 0,374) y la neutropenia del 10 vs. 23,68% (p = 0,204). La mediana del porcentaje de descenso plaquetario en hiperfiltradores frente a normofiltradores fue del −10,36 (−193,33–62,03) vs. 2,68 (−163,16–82,71) (p = 0,333), de hemoglobina 2,50 (−12,12–25,93) vs. 9,09 (−17,72–30,63) (p = 0,047) y de neutrófilos 9,14 (−73,91–76,47) vs. 27,33 (−86,66–90,90) (p = 0,093). El 10,5% con filtrado normal presentó toxicidad grado 3 o superior, el 2,6% interrumpió el tratamiento y el 5,2% requirieron transfusiones... (AU)

Objectives Linezolid is an oxazolidin commonly related to the development of hematological toxicity, being renal clearance the major factor involved in the drug clearance. The aim of this study is to evaluate the influence of increased filtration rates in the incidence of linezolid-induced hematological toxicity by comparing augmented renal clearance (ARC) patients versus normal renal function patients. Material and methods A retrospective, observational study was conducted on hospitalized patients treated with linezolid for 5 days or more during 2014–2019 period. Patients with a filtration rate of ≥130 mL/min versus reference patients (60–90 mL/min) were compared. Hematological toxicity was defined as a decrease of 25% in platelets, of 25% in hemoglobin and/or 50% in neutrophils from baseline. Toxicity relevance was classified according to Common Terminology Criteria for Adverse Events v5. Incidence of hematological toxicity between groups was studied by chi-square and Fisher test. Furthermore, percentaje disminution of all three parameters was calculated and compared by Mann–Whitney test and treatment interruption and tranfusion requirements were registered. Results 30 ARC patients and 38 reference patients were included. Hematological toxicity was observed in 16.66% of ARC patients vs 44.74% of reference patients (p = 0.014); thrombocytopenia in 13.33% vs 36.84% (p = 0.051), anemia in 3.3% vs 10.52% (p = 0.374) and neutropenia in 10% vs 23.68% (p = 0.204). Median percentaje of platelets decrease in ARC patients was −10.36 (−193.33–62.03) vs 2.68 (−163.16–82.71) in reference patients (p = 0.333), while hemoglobin decrease was 2.50 (−12.12–25.93) vs 9.09 (−17.72–30.63) (p = 0.047) and neutrophils decrease was 9.14 (−73.91–76.47) vs 27.33 (−86.66–90.90) (p = 0.093). 10.5% of normal renal function patients reported at least one adverse event grade 3 or superior while 2.6% of them interrupted treatment and 5.2% had tranfusion requirements... (AU)

Influence of augmented renal clearance on the lower incidence of linezolid-related hematological toxicity. / Influencia de la hiperfiltración glomerular en la menor toxicidad hematológica inducida por linezolid.

OBJECTIVES: Linezolid is an oxazolidin commonly related to the development of hematological toxicity, being renal clearance the major factor involved in the drug clearance. The aim of this study is to evaluate the influence of increased filtration rates in the incidence of linezolid-induced hematological toxicity by comparing augmented renal clearance (ARC) patients versus normal renal function patients. MATERIAL AND METHODS: A retrospective, observational study was conducted on hospitalized patients treated with linezolid for 5 days or more during 2014-2019 period. Patients with a filtration rate of ≥130 mL/min versus reference patients (60-90 mL/min) were compared. Hematological toxicity was defined as a decrease of 25% in platelets, of 25% in hemoglobin and/or 50% in neutrophils from baseline. Toxicity relevance was classified according to Common Terminology Criteria for Adverse Events v5. Incidence of hematological toxicity between groups was studied by chi-square and Fisher test. Furthermore, percentaje disminution of all three parameters was calculated and compared by Mann-Whitney test and treatment interruption and tranfusion requirements were registered. RESULTS: 30 ARC patients and 38 reference patients were included. Hematological toxicity was observed in 16.66% of ARC patients vs 44.74% of reference patients (p = 0.014); thrombocytopenia in 13.33% vs 36.84% (p = 0.051), anemia in 3.3% vs 10.52% (p = 0.374) and neutropenia in 10% vs 23.68% (p = 0.204). Median percentaje of platelets decrease in ARC patients was -10.36 (-193.33-62.03) vs 2.68 (-163.16-82.71) in reference patients (p = 0.333), while hemoglobin decrease was 2.50 (-12.12-25.93) vs 9.09 (-17.72-30.63) (p = 0.047) and neutrophils decrease was 9.14 (-73.91-76.47) vs 27.33 (-86.66-90.90) (p = 0.093). 10.5% of normal renal function patients reported at least one adverse event grade 3 or superior while 2.6% of them interrupted treatment and 5.2% had tranfusion requirements. No major events or interruptions were reported in ARC patients. CONCLUSION: Our findings suggest a lower incidence and clinical relevance of hematological toxicity in augmented renal clearance patients. Thrombocytopenia was the major event in both populations. This might be related to a lower exposure to the drug due to the higher clearance and likely lower therapeutic efficiency. These results suggest a potential benefit of therapeutic drug monitoring on high risk patients.

Rivaroxabán e inhibidores selectivosde la recaptación de serotonina: Análisis comparativo del riesgo de sangrado / Rivaroxaban and selective serotonin reuptake inhibitors: Bleeding risk resulting from their concomitant use

Objetivo: La combinación de rivaroxabán e inhibidores selectivos de larecaptación de serotonina presenta un riesgo de interacción farmacodinámicay farmacocinética que depende del tipo de inhibidor selectivo dela recaptación de serotonina empleado, ya que algunos son inhibidoresdel citocromo p450, mientras que otros no lo son. El objetivo del presenteestudio fue evaluar con datos de vida real si el tipo de inhibidor selectivode la recaptación de serotonina utilizado influye en la frecuencia y en lagravedad de sangrado en pacientes anticoagulados con rivaroxabán.Método: Estudio observacional, longitudinal, retrospectivo y unicéntrico,realizado entre enero de 2016 y febrero de 2020 en pacientes ≥ 18 añosque recibían rivaroxabán, en indicaciones autorizadas y financiadas, y queestaban siendo tratados concomitantemente con inhibidores selectivos dela recaptación de serotonina. Se establecieron dos cohortes en funcióndel inhibidor selectivo de la recaptación de serotonina coadministrado:inhibidores del CYP3A4 (grupo 1) —sertralina, fluoxetina y paroxetina—,y no inhibidores del CYP3A4 (grupo 2) —citalopram y escitalopram—. Seanalizaron los eventos hemorrágicos, la gravedad del sangrado, la dosisdiaria de rivaroxabán y la medicación concomitante que pudiese influir enel riesgo de sangrado.Resultados: Se incluyeron 146 pacientes (89 en el grupo 1 y 57 en elgrupo 2) y se identificaron un total de 35 eventos hemorrágicos (24% delos pacientes), de los que 12 fueron eventos mayores y 23 menores. Lafrecuencia de sangrado fue ligeramente mayor en el grupo 1 que en el 2(25,8% versus 21%), pero no se encontraron diferencias significativas entre ambos grupos, ni tampoco en la frecuencia de sangrados mayores (10,1%versus 5,3%; p = 0,235) o menores (13,5% versus 15,8%; p = 0,496).

Objective: The combination of selective serotonin reuptake inhibitorswith rivaroxaban may result in a dual interaction (pharmacokinetic andpharmacodynamic) depending on the type of selective serotonin reuptakeinhibitor employed (CYP3A4-inhibiting vs. non-CYP3A4 inhibiting). Thepurpose of this study was to use real world data to determine if the typeof selective serotonin reuptake inhibitor used plays a role in the risk andseverity of bleeding in patients receiving rivaroxaban.Method: This was a single-center retrospective longitudinal observationalstudy carried out between January 2016 and February 2020 inpatients aged 18 years or older treated concurrently with rivaroxaban(prescribed for treatments) and a selective serotonin reuptake inhibitor. Patients were divided into two groups according to the selective serotoninreuptake inhibitor they received, i.e., a CYP3A4 inhibitor (group 1): sertraline,fluoxetine and paroxetine, or a non-CYP3A4 inhibitor (group 2):citalopram and escitalopram. We analyzed the bleeding events and severity,the daily dose of rivaroxaban used and the medication administeredconcomitantly.Results: A total of 146 patients were included (89 in group 1 and 57in group 2) and 35 bleeding events (24% of patients) were identified, of which 12 were major and 23 were minor. The bleeding rate was higherin group 1 (25.8% vs 21.0%) but there were no differences in major bleeding(10.1% vs 5.3%; p = 0.235) or minor bleeding (13.5% vs 15.8%;p = 0.496).

Interacción entre ácido valproico con meropenemo ertapenem en pacientes con epilepsia: relevancia clínica y resultados de la intervención farmacéutica / Interaction between valproic acid and meropenem or ertapenem in patients with epilepsy: clinical relevance and results from pharmaceutical intervention

Objetivo: La interacción entre ácido valproico y carbapenems está descrita en la literatura y conlleva una disminución de los niveles plasmáticosde ácido valproico. Los objetivos son evaluar su relevancia en la prácticaclínica, conocer las variables que se asocian a un incremento de crisisepilépticas y analizar el impacto de la intervención farmacéutica paraevitar las consecuencias de dicha interacción.Método: En este estudio observacional retrospectivo se estudiaronpacientes con epilepsia hospitalizados entre 2016 y 2020. Se registróel tratamiento farmacológico prescrito en el ingreso y se revisó la presencia de otras interacciones que redujeran la concentración plasmática deácido valproico. La frecuencia de crisis epilépticas durante el año previo alingreso se comparó con la correspondiente al periodo de interacción. Serealizó una intervención en todos los episodios con la interacción detectada informando al prescriptor sobre la interacción y proponiendo sustitución de la antibioterapia, así como monitorización farmacocinética deácido valproico.Resultados: Se incluyeron 37 episodios. El 58,1% eran varones y lamediana de edad fue de 70 años. El 56,8% de los pacientes recibiómeropenem y el 43,2% restante, ertapenem. Para la duración del tratamiento concomitante entre ácido valproico y el carbapenem prescrito se obtuvo una mediana de 4 días. Se halló una razón de tasas de incidencia de 2,60 (intervalo de confianza del 95%: 1,61-4,21), por lo queesta interacción se asocia a una mayor frecuencia de crisis epilépticas.Se asoció una mayor frecuencia de crisis estadísticamente significativaen los pacientes tratados con más de un fármaco antiepiléptico. Los farmacéuticos hospitalarios detectaron 24 episodios (64,9%). (AU)

Objective: The literature has described the interaction between valproicacid and carbapenems. This interaction leads to decreases in plasmaconcentrations of valproic acid. The main objectives of this study were toassess its relevance in clinical practice, to identify variables associatedwith increased seizure episode rates, and to analyse the impact of pharmaceutical intervention on avoiding the effects of this interaction.Method: An observational retrospective study of inpatients withepilepsy admitted between 2016 and 2020. Their pharmacologicaltreatment throughout admission was recorded, and the presence of otherinteractions leading to decreased plasma concentrations of valproicacid was reviewed. The seizure rate during the year prior to admissionwas compared to that during the interaction period. For every episodein which the interaction was detected, an intervention was conducted byproviding the prescriber with information on the interaction and suggesting a change of antibiotherapy as well as the pharmacokinetic monitoring of valproic acid.Results: 37 episodes were included. 58.1% of the patients were maleand median age was 70 years. In total, 56.8% of the patients receivedmeropenem and 43.2% received ertapenem. The median duration of concomitant treatment with valproic acid and carbapenem was 4 days. The incidence rate ratio was 2.60 (95% confidence interval: 1.61-4.21). Thus,this interaction was associated with a higher seizure rate. A statistically significant association was found between higher seizure rates andpatients treated with more than one anti-epileptic drug. Hospital pharmacists detected 24 episodes (64.9%). In total, 17 interventions (70.8%)were accepted and 13 combinations were discontinued. Pharmacokineticmonitoring was conducted in 13 episodes (35.1%) and infratherapeuticlevels were found in all of them. (AU)

Interaction between valproic acid and meropenem or ertapenem in patients with epilepsy: clinical relevance and results from pharmaceutical intervention.

OBJECTIVE: The literature has described the interaction between valproic acid  and carbapenems. This interaction leads to decreases in plasma concentrations  of valproic acid. The main objectives of this study were  to assess its relevance in clinical practice, to identify variables associated with  increased seizure episode rates, and to analyse the impact of pharmaceutical intervention on avoiding the effects of this interaction. METHOD: An observational retrospective study of inpatients with epilepsy  admitted between 2016 and 2020. Their pharmacological treatment throughout  admission was recorded, and the presence of other interactions  leading to decreased plasma concentrations of valproic acid was reviewed. The  seizure rate during the year prior to admission was compared to that during  the interaction period. For every episode in which the interaction was detected, an intervention was conducted by providing the prescriber with information on  the interaction and suggesting a change of antibiotherapy as well as the  pharmacokinetic monitoring of valproic acid. RESULTS: 37 episodes were included. 58.1% of the patients were male and  median age was 70 years. In total, 56.8% of the patients received meropenem  and 43.2% received ertapenem. The median duration of  concomitant treatment with valproic acid and carbapenem was 4 days. The  incidence rate ratio was 2.60 (95% confidence interval: 1.61-4.21). Thus, this  interaction was associated with a higher seizure rate. A statistically significant  association was found between higher seizure rates and patients treated with  more than one anti-epileptic drug. Hospital pharmacists detected 24 episodes  (64.9%). In total, 17 interventions (70.8%) were accepted and 13  combinations were discontinued. Pharmacokinetic monitoring was conducted in  13 episodes (35.1%) and infratherapeutic levels were found in all of them. CONCLUSIONS: The interaction between valproic acid and meropenem or ertapenem is clinically relevant. It is recommended that this combination should be avoided provided that a viable alternative is available.  Pharmaceutical intervention may contribute to preventing seizures associated with this combination.

Objetivo: La interacción entre ácido valproico y carbapenems está descrita en  la literatura y conlleva una disminución de los niveles plasmáticos de ácido  valproico. Los objetivos son evaluar su relevancia en la práctica clínica, conocer  las variables que se asocian a un incremento de crisis epilépticas y  analizar el impacto de la intervención farmacéutica para evitar las  consecuencias de dicha interacción.Método: En este estudio observacional retrospectivo se estudiaron pacientes  con epilepsia hospitalizados entre 2016 y 2020. Se registró el tratamiento  farmacológico prescrito en el ingreso y se revisó la presencia de otras  interacciones que redujeran la concentración plasmática de ácido valproico. La  frecuencia de crisis epilépticas durante el año previo al ingreso se comparó con  la correspondiente al periodo de interacción. Se realizó una intervención  en todos los episodios con la interacción detectada informando al prescriptor  sobre la interacción y proponiendo sustitución de la antibioterapia, así como  monitorización farmacocinética de ácido valproico.Resultados: Se incluyeron 37 episodios. El 58,1% eran varones y la mediana  de edad fue de 70 años. El 56,8% de los pacientes recibió meropenem y el  43,2% restante, ertapenem. Para la duración del tratamiento concomitante  entre ácido valproico y el carbapenem prescrito  se obtuvo una mediana de 4  días. Se halló una razón de tasas de incidencia de 2,60 (intervalo de confianza  del 95%: 1,61-4,21), por lo que esta interacción se asocia a una mayor  frecuencia de crisis epilépticas. Se asoció una mayor frecuencia de crisis  estadísticamente significativa en los pacientes tratados con más de un fármaco  antiepiléptico. Los farmacéuticos hospitalarios detectaron 24  episodios (64,9%). Se aceptaron 17 intervenciones farmacéuticas (70,8%) y  se suprimieron 13 combinaciones. Se realizó monitorización farmacocinética en  13 episodios (35,1%) y en todos se hallaron niveles infraterapéuticos. Conclusiones: La interacción entre ácido valproico y meropenem o ertapenem  es clínicamente relevante y se recomienda evitarla siempre que  existan alternativas viables. La intervención farmacéutica puede contribuir a  prevenir las crisis epilépticas favorecidas por esta combinación.

Rivaroxaban and selective serotonin reuptake inhibitors: Bleeding risk resulting from their concomitant use.

OBJECTIVE: The combination of selective serotonin reuptake inhibitors with  rivaroxaban may result in a dual interaction (pharmacokinetic and pharmacodynamic) depending on the type of selective serotonin reuptake inhibitor employed (CYP3A4-inhibiting vs. non-CYP3A4 inhibiting).  The purpose of this study was to use real world data to determine if the type of  selective serotonin reuptake inhibitor used plays a role in the risk and severity of bleeding in patients receiving rivaroxaban. Method: This was a single-center retrospective longitudinal observational study carried out between January 2016 and February 2020 in patients aged 18 years or older treated concurrently with rivaroxaban (prescribed for treatments) and a selective serotonin reuptake  nhibitor. Patients were divided into two groups according to the selective  serotonin reuptake inhibitor they received, i.e., a CYP3A4 inhibitor (group 1):  sertraline, fluoxetine and paroxetine, or a non-CYP3A4 inhibitor (group 2): citalopram and escitalopram. We analyzed the bleeding events and  everity, the daily dose of rivaroxaban used and the medication administered concomitantly. RESULTS: A total of 146 patients were included (89 in group 1 and 57 in group  2) and 35 bleeding events (24% of patients) were identified, of  which 12 were  major and 23 were minor. The bleeding rate was higher in group 1  (25.8% vs 21.0%) but there were no differences in major bleeding (10.1% vs  5.3%; p = 0.235) or minor bleeding (13.5% vs 15.8%; p = 0.496). The  bleeding rate with a daily rivaroxaban dose of 20 mg was 9% (8/89) in group 1  and 14% (8/57) in group 2 (p = 0.2137), as compared with 16.9% (15/89)  in group 1 versus 7% (4/57) in group 2 (p = 0.042) for a daily 15 mg dose. CONCLUSIONS: Although the type of selective serotonin reuptake inhibitor used  concurrently with rivaroxaban was not found to influence the patients' bleeding  risk, a significant increase in the risk of bleeding was  bserved based on the dose of rivaroxaban used.

OBJETIVO: La combinación de rivaroxabán e inhibidores selectivos de la recaptación de serotonina presenta un riesgo de interacción  farmacodinámica y farmacocinética que depende del tipo de inhibidor selectivo  de la recaptación de serotonina empleado, ya que algunos son inhibidores del  citocromo p450, mientras que otros no lo son. El objetivo del presente estudio  fue evaluar con datos de vida real si el tipo de inhibidor selectivo de la  recaptación de serotonina utilizado influye en la frecuencia y en la gravedad de  sangrado en pacientes anticoagulados con rivaroxabán. Método: Estudio observacional, longitudinal, retrospectivo y unicéntrico, realizado entre enero de 2016 y febrero de 2020 en pacientes ≥  18 años que recibían rivaroxabán, en indicaciones autorizadas y financiadas, y  que estaban siendo tratados concomitantemente con inhibidores selectivos de  la recaptación de serotonina. Se establecieron dos cohortes en función del  inhibidor selectivo de la recaptación de serotonina coadministrado: inhibidores  del CYP3A4 (grupo 1) ­sertralina, fluoxetina y paroxetina­, y no inhibidores  del CYP3A4 (grupo 2) ­citalopram y escitalopram­. Se analizaron los eventos  hemorrágicos, la gravedad del sangrado, la dosis diaria de rivaroxabán y la  medicación concomitante que pudiese influir en el riesgo de sangrado. RESULTADOS: Se incluyeron 146 pacientes (89 en el grupo 1 y 57 en el grupo  2) y se identificaron un total de 35 eventos hemorrágicos (24% de los  pacientes), de los que 12 fueron eventos mayores y 23 menores. La frecuencia  de sangrado fue ligeramente mayor en el grupo 1 que en el 2 (25,8% versus 21%), pero no se encontraron diferencias significativas entre  ambos grupos, ni tampoco en la frecuencia de sangrados mayores  (10,1% versus 5,3%; p = 0,235) o menores (13,5% versus 15,8%; p =  0,496). La frecuencia de eventos hemorrágicos con la dosis de 20 mg fue del  9% (8/89) en el grupo 1 y del 14% (8/57) en el grupo 2 (p = 0,2137), mientras que con una dosis de 15 mg la frecuencia de eventos fue del 16,9% (15/89) en el grupo 1 y del 7% (4/57) en el grupo 2 (p = 0,042). CONCLUSIONES: No se han hallado diferencias significativas en el riesgo de  sangrado según el tipo de inhibidor selectivo de la recaptación de serotonina  que se administre de forma concomitante al rivaroxabán. Sí se han observado  diferencias significativas en función de la dosis de rivaroxabán utilizada.