Primary care pharmacist-led medication review in older adult patients in coordination with general practitioners: an observational retrospective cohorts study.

Background: Polypharmacy and risk of potentially inappropriate prescribing (PIP) in older adult are being continuously increased. Including a primary care pharmacist (PCP) in the healthcare team is associated with lower rates of medication-related problems (MRPs). Objectives: To determine the impact (in terms of variation of PIP, MRPs and polymedication) of treatment reviews (TR) carried out by the PCP by comparing two cohorts: standard TR vs coordinated TR with prescribing General Practitioners (GP). To assess possible health outcomes in both groups 6 months post-TR. Methods: This is an observational study of two retrospective cohorts (2018 to 2020). All patients who met the inclusion/exclusion criteria were analyzed. Patients ≥65 years, who underwent complete TR by the PCP were included. Patients in a situation of exitus at the time of TR and those who underwent a partial TR were excluded. Control group cohort consisted of patients who underwent standard TR, and intervention group cohort consisted of those who underwent TR coordinated with GP. Sociodemographic, clinical and pharmacological variables were analyzed. Results: 181 patients were enrolled. Mean age 84.4 ± 7.2 years, 78.5% women. Variables (GP-coordinated vs standard TRs) pre-post: decrease in drugs/patient 1.9 (95%CI: 1.4-2.4) vs 0.6 (95%CI: 0.2-1.3), p < 0.05; decrease in MRPs/patient 3.1 (95%CI: 2.8-3.4) vs 1.0 (95%CI: 0.6-1.4), p < 0.05; decrease in PIP/patient 2.0 (95% CI: 1.6-2.2) vs 0.6 (95% CI: 0.2-0.9), p < 0.05. Health outcomes: there was significant difference in average primary-care visits/patient 1.3 ± 0.5 vs 2.2 ± 1.8, p < 0.05. Conclusions: Multidisciplinary interventions between PCP and GP, together with a systematic approach to TR can improve the quality of pharmacotherapy in the elderly. Prospective large follow-up studies are needed to demonstrate a positive trend in health outcomes.

[Analysis of the valproic acid-meropenem interaction in hospitalised patients]. / Análisis de la interacción ácido valproico-meropenem en pacientes hospitalizados.

INTRODUCTION: Published data demonstrate a serious interaction between valproic acid and meropenem. However, recommendations about the management of concomitant treatment are contradictory; some experts recommend closer monitoring of valproic acid serum concentrations and others recommend avoiding concurrent therapy. The purpose of this study is to critically analyse the interaction and to evaluate the impact of pharmaceutical intervention in the use of these drugs in hospitalised patients. MATERIAL AND METHODS: Study of the concomitant prescription of valproic acid and meropenem in a general hospital of 1,080 beds divided in to two periods; the first period was retrospective and observational and it was followed by a prospective period involving pharmaceutical intervention. The prescription habits between both periods were compared. RESULTS: A total of 26 patients received concurrent treatment with valproic acid and meropenem (13 per period) and none of them maintained therapeutic serum levels of the antiepileptic drug. Pharmaceutical intervention modified prescription habits, reducing by half the number of days of concomitant treatment, changing the antibiotherapy and/or monitoring serum concentrations more often. CONCLUSIONS: The interaction between valproic acid and meropenem is serious, especially because of the dramatic decrease in the antiepileptic serum concentrations. The concomitant use of both drugs should be avoided, replacing the antibiotherapy empirically, or according to the resistance profiles of the microorganism and maintaining the same the anti-epileptic treatment.

[Analysis of errors in manual versus electronic prescriptions in trauma patients]. / Análisis de errores de la prescripción manual comparados con la prescripción electrónica asistida en pacientes traumatológicos.

OBJECTIVE: To detect, quantify, and compare the medication error produced with manual versus electronically assisted prescription systems. METHODS: A descriptive, observational, prospective study in two traumatology hospitalisation units; one with manual prescriptions and the other with electronically assisted prescriptions. Prescription errors were determined. RESULTS: We analysed 1,536 lines of treatment (393 treatment forms) from 164 patients. With manual prescriptions, we detected errors in 19.54% of cases, compared to 9.4% in electronically assisted prescriptions. Omission errors were significantly lower with electronically assisted prescriptions, especially with drugs that act upon the central nervous system. CONCLUSIONS: Prescription error has decreased by 53% since computerising the prescription process. This is particularly useful for omission errors, as prescription is more complete. The decrease in error regarding drugs that act on the central nervous system stands out.

Effects of hospital pharmacist interventions on health outcomes in older polymedicated inpatients: a scoping review.

PURPOSE: To identify the evidence that supports the effect of interventions made by hospital pharmacists, individually or in collaboration with a multidisciplinary team, in terms of healthcare outcomes, a more effective utilization of resources and lower costs in older polymedicated inpatients. METHODS: We searched the following databases: MEDLINE, EMBASE and the Cochrane Library. We also conducted a hand search by checking the references cited in the primary studies and studies included in reviews identified during the process of research. Four review authors working by pairs searched for studies, extracted data, and drew up the results tables. RESULTS: Twenty-six studies were included in the review. In 13 of them pharmacists carried out their intervention exclusively while the patients were in hospital, whereas in 13 interventions were delivered during admission and after hospital discharge. Outcomes identified were mortality, length of stay, visits to the emergency department, readmissions and reported quality of life, among others. Pharmacist interventions were found to be beneficial in fifteen studies, specifically on hospital readmissions, visits to the emergency department and healthcare costs. CONCLUSION: There is no hard evidence demonstrating the effectiveness of hospital pharmacist interventions in older polymedicated patients. Mortality does not show as a relevant outcome. Other health care outcomes, such as hospital readmissions, visits to the emergency department and healthcare costs, seem to be more relevant and amenable to change. Interventions that include pharmacists in multidisciplinary geriatric teams seem to be more promising that isolated pharmacist interventions. Interventions prolonged after hospital discharge seem to be more appropriate that interventions delivered only during hospital admission. Better-designed studies should be conducted in the future to provide further insight into the effect of hospital pharmacist interventions.

[New technologies applied to the medication-dispensing process, error analysis and contributing factors]. / Nuevas tecnologías aplicadas al proceso de dispensación de medicamentos. Análisis de errores y factores contribuyentes.

OBJECTIVE: Calculate error prevalence occurred in different medication-dispensing systems, the stages of occurrence, and contributing factors. METHODOLOGY: Prospective observational study. The staging of the dispensing process were reviewed in five dispensing systems: Stock, Unitary-Dose dispensing systems (UDDS) without Computerized Prescription Order Entry (CPOE), CPOE-UDDS, Automated Dispensing Systems (ADS) without CPOE and CPOE-ADS. Dispensing errors were identified, together with the stages of occurrence of such errors and their contributing factors. RESULTS: 2,181 errors were detected among 54,169 opportunities of error. Error-rate: Stock, 10.7%; no-CPOE-UDDS, 3.7%, CPOE-UDDS, 2.2%, no-CPOE-ADS, 20.7%; CPOE-ADS, 2.9%. Most frequent stage when error occurs: Stock, preparation of order; no-CPOE-UDDS and CPOE-UDDS, filling of the unit dose cart; no-CPOE-ADS and CPOE-ADS, filling of the ADS. Most frequent error: Stock, no-CPOE-ADS and CPOE-ADS, omission; CPOE-UDDS, different amount of drug and no-CPOE-UDDS, extra medication. Contributing factor: Stock, CPOE-ADS and no-CPOE-ADS, stock out/supply problems; CPOE-UDDS, inexperienced personnel and deficient communication system between professionals; no-CPOE-UDDS, deficient communication system between professionals. CONCLUSIONS: Applying new technologies to the dispensing process has increased its safety, particularly, implementation of CPOE has enabled to reduce dispensing errors.

Pharmacist comprehensive review of treatment compared with STOPP-START criteria to detect potentially inappropriate prescription in older complex patients.

OBJECTIVES: To compare potentially inappropriate prescribing (PIP) according to the clinical judgement of the pharmacist with PIP according to explicit STOPP-START criteria in institutionalised and hospitalised patients with multiple pathologies. To describe and compare the main pharmacological groups involved and determine the factors associated with the detection of PIP in these patients. METHOD: A prospective multicentre observational study of institutionalised and hospitalised multipathology patients aged >65 years. A specialised pharmacist used his best clinical judgement to detect PIP based on a comprehensive review of the complete chronic treatment of patients, which is an essential activity in interdisciplinary care. STOPP-START criteria were used as an aid tool to detect PIP. The main variable was the number of PIP incidents detected. RESULTS: Detected PIP incidents were analysed in 338 patients. Clinical judgement detected more PIP incidents (35%) than did STOPP-START criteria. More PIP incidents unrelated to these criteria were detected in institutionalised patients than in hospitalised patients. Clinical judgement mainly detected PIP incidents related to incorrect doses and drug interactions (p<0.001); however, STOPP-START criteria mainly detected PIP incidents related to drug duplication and insufficiently treated diagnosis or symptoms (p=0.001 and p<0.001). In total, 93.8% of the PIP incidents were detected in polypharmacy patients (≥5 drugs). Institutionalised and high-level polypharmacy (≥10 drugs) patients were at the highest risk of PIP. CONCLUSIONS: A large number of PIP incidents were detected in institutionalised and hospitalised patients with multiple pathologies. The inclusion of a pharmacist in the multidisciplinary team facilitated the detection of PIP incidents, particularly in the institutionalised population and patients treated with high-level polypharmacy which were not detected by explicit STOPP-START criteria.

[Prescription errors after the implementation of an electronic prescribing system]. / Errores de prescripción tras la implantación de un sistema de prescripción electrónica asistida.

OBJECTIVE: This study sets out to identify, compare and evaluate the medication errors of a manual prescribing system and an electronic prescribing system during the prescription and transcription phases. METHOD: A prospective study of two clinical in-patient units (pneumology and infectious diseases) in one general hospital. Two phases were studied; before and after an electronic prescribing system was implemented. Each phase lasted one month. A comparative analysis was carried out of the medication errors in the medical prescription process, the transcription process and the administration recording process carried out by nursing staff as well as the pharmacist s transcriptions/validations. RESULTS: A total of 3,908 patient treatment errors and 129 patient identification errors were detected during both of the periods studied. The rate of errors in patient identification or treatment orders using the manual prescribing system was 14.4 against 1.3% after the electronic system was implemented. The relative risk reduction for infectious diseases and pneumology was 100 and 85.44%, respectively (statistically significant). In general, relative risk reduction was achieved in both units, oscillating between 78.91 and 100%. The absolute risk reduction oscillated between 5.09 and 30.45% for errors in drug data, doses, frequency/time and route of administration. These results were statistically significant. CONCLUSIONS: The electronic prescribing system has reduced errors in the identification, prescription and transcription of pharmacological treatment and has consequently helped to improve the quality and safety of drug treatment received by patients.

[Detection and analysis of adverse drug reactions in a general hospital's emergency department]. / Detección y análisis de reacciones adversas a medicamentos en el servicio de urgencias de un hospital general.

OBJECTIVE: To detect and analyze adverse drug reactions (ADR) leading to emergency room visits in our hospital, as well as their severity and outcome, and medications most commonly involved, from selected alerting diagnoses. METHOD: A retrospective study for the period from January 2003 to December 2004, where all reports by the emergency department including our wanted diagnoses were reviewed. RESULTS: A total of 1,626 reports with alerting diagnoses were found, of which 444 (27.3%) were confirmed as potential adverse drug reactions. Of 444 cases, 345 (77.7%) were discharged to their homes and 90 (20%) were admitted. In all, 52.9% of adverse drug reactions were considered moderate, and 19.6% were considered serious. The major age group involved was that of patients older than 65 years (65.1%), and was involved in 83.9% of adverse drug reactions. Drugs most commonly involved included insulins (26.1%), diuretics (17.3%), digoxin (10.9%), and oral antidiabetics (9.5%). Major organs and systems involved included the endocrine system (55.6%), musculoskeletal system (11%) and cardiovascular system (10.8%). CONCLUSIONS: Drugs commonly used in clinical practice, including insulins, diuretics or oral antidiabetics induce many of the adverse reactions that lead patients to visit emergency departments. A closer monitoring of therapies is still needed to prevent adverse drug reactions.

[Digitalis intoxication secondary to treatment with clarithromycin]. / Original Breve Intoxicación digitálica secundaria al tratamiento con claritromicina.

OBJECTIVE: The goal of this study was to investigate the percentage of patients concurrently receiving digoxin and clarithromycin who exhibited serum digoxin concentrations above the therapeutic range because of a likely interaction between both drugs, and whether digitalis intoxication ensued. METHOD: A descriptive, retrospective study carried out from January 2002 to December 2003 in all inpatients concurrently receiving digoxin and clarithromycin whose serum digoxin concentrations were monitored by the Pharmacy Department s Pharmacokinetics Section. RESULTS: Twenty-six patients having received digoxin and clarithromycin concurrently during their hospital stay were included in the study. Of these, 12 patients (46.2%) had serum digoxin concentrations above the therapeutic range: 7 received digoxin in doses unsuited for their age and/or renal function, and 2 fell short of the mean period of time considered adequate for an interaction to occur. Therefore, only 3 patients had serum digoxin concentrations above the therapeutic range, probably because of an interaction with clarithromycin, and all three had digitalis intoxication symptoms. CONCLUSIONS: According to the results of our study, 11.5% of patients concurrently receiving digoxin and clarithromycin had serum digoxin concentrations above the therapeutic range because of a likely interaction between these two drugs, with digitalis intoxication ensuing. Thus, we deem it necessary to monitor serum digoxin concentrations in patients receiving clarithtomycin.

[Improving drug prescribing in the elderly: a new edition of STOPP/START criteria]. / Mejorando la prescripción de medicamentos en las personas mayores: una nueva edición de los criterios STOPP-START.

Inappropriate use of drugs in older patients may have an adverse impact on several individual health outcomes, such as increasing the prevalence of adverse drug reactions, morbidity and mortality, and geriatric syndromes, as well as on health care systems, such as increased costs and longer hospital stays. Explicit criteria of drug appropriateness are increasingly used to detect and prevent inappropriate use of drugs, either within a comprehensive geriatric assessment or as tool used by different multidisciplinary geriatric teams. STOPP-START criteria, first published in 2008 (in Spanish in 2009), are being adopted as reference criteria throughout Europe. The Spanish version of the new 2014 edition (recently published in English) of the STOPP-START criteria is presented here. A review of all the papers published in Spain using the former version of these criteria is also presented, with the intention of promoting their use and for research in different health care levels.

[Effect of modal computer-based alerts on the prescription of valproic acid and meropenem]. / Impacto de las alertas interactivas modales en la prescripción informatizada de ácido valproico y meropenem.

OBJECTIVE: To analyze the effect of modal computer-based alerts on the concomitant prescription of valproic acid (VPA) and meropenem. MATERIAL AND METHOD: Analytical intervention study conducted in a tertiary hospital for eleven months. Hospitalized patients with a diagnosis of epilepsy and treated with VPA and meropenem in concomitant therapy were included. In the computerized prescription order entry software an automatic non-modal alert was reconverted to a modal one. This was triggered when the physician introduced VPA and meropenem together in the same prescription. To measure the effect of this alert the prescription habits were compared with a previous period in which the alert was not modal. RESULTS: Modal computer-based alert modified the prescription habit by reducing the number of patients with concomitant treatment from 13 to 4 (P=.046). However, it was notable that the number of requests for VPA serum levels decreased, and the average number of concomitant days of treatment rose from 4.7 to 8.75 in those patients in which none of the drugs was suspended. CONCLUSIONS: The implementation of modal computer-based alerts reduces patient exposure to concomitant treatment with meropenem and VPA.

[Failure modes and effects analysis in the prescription, validation and dispensing process]. / Análisis modal de fallos y efectos del proceso de prescripción, validación y dispensación de medicamentos.

OBJECTIVE: To apply a failure modes and effects analysis to the prescription, validation and dispensing process for hospitalised patients. METHODS: A work group analysed all of the stages included in the process from prescription to dispensing, identifying the most critical errors and establishing potential failure modes which could produce a mistake. The possible causes, their potential effects, and the existing control systems were analysed to try and stop them from developing. The Hazard Score was calculated, choosing those that were ≥ 8, and a Severity Index = 4 was selected independently of the hazard Score value. Corrective measures and an implementation plan were proposed. RESULTS: A flow diagram that describes the whole process was obtained. A risk analysis was conducted of the chosen critical points, indicating: failure mode, cause, effect, severity, probability, Hazard Score, suggested preventative measure and strategy to achieve so. Failure modes chosen: Prescription on the nurse's form; progress or treatment order (paper); Prescription to incorrect patient; Transcription error by nursing staff and pharmacist; Error preparing the trolley. CONCLUSIONS: By applying a failure modes and effects analysis to the prescription, validation and dispensing process, we have been able to identify critical aspects, the stages in which errors may occur and the causes. It has allowed us to analyse the effects on the safety of the process, and establish measures to prevent or reduce them.

Adverse drug reactions which provoke hospital admission.

OBJECTIVE: To identify, classify and quantify the frequency of negative clinical adverse drug reactions (ADR) resulting in hospital admission from the emergency department (ED). To determine ADR preventability, identify ADR-related admission factors, calculate related costs and recognise which drugs are the most often involved. METHOD: Cross-sectional, prospective and observational study of patients that were admitted to hospital from the ED. We used the Dader method to detect ADR. We classified ADR in accordance with the Tercer Consenso de Granada (third Granada consensus), and calculated ADR preventability using the Schumock and Thornton scales (modified by Otero et al), and ADR severity according to Schneider. We considered the direct costs generated during the hospital stay for the economic study. We analysed the correlation between ADR and age, sex, kidney and liver failure, and drug use. We used multiple logistic regression analysis to identify risk factors. RESULTS: 19.4% of admissions were the direct consequence of ADR, 65% of which were preventable. Antineoplastic therapy and immunosuppressants caused 38% of ADR. 20.4% of admissions had to be transferred to the intensive care unit (ICU) or caused permanent damage. We found statistical significance between ADR and patients undergoing hormonal therapy, 'high risk' drugs and those admitted to the endocrinology department. The ADR-associated cost was €237,377. CONCLUSIONS: ADR-related admission is a problem with a high prevalence, and most cases are preventable.

Mejorando la prescripción de medicamentos en las personas mayores: una nueva edición de los criterios STOPP-START / Improving drug prescribing in the elderly: A new edition of STOPP/START criteria

La utilización inapropiada de los medicamentos en los pacientes mayores tiene graves consecuencias en su salud —aumento del riesgo de sufrir reacciones adversas o síndromes geriátricos, mayor morbimortalidad— y en el sistema sanitario —aumento de costes, estancias hospitalarias excesivas. Para detectar y prevenir la utilización inadecuada de fármacos se está imponiendo progresivamente el uso de criterios explícitos, que pueden usarse dentro de la evaluación geriátrica exhaustiva o como parte de la actuación de diversos equipos multidisciplinares geriátricos. Los criterios STOPP-START, publicados por vez primera en 2008 (y en español en 2009), se están imponiendo como criterios de referencia en el ámbito europeo. Se presenta aquí la versión en español de la nueva edición (2014) de estos criterios, recientemente publicados en inglés. Además, se revisan en este artículo las publicaciones que han usado la versión inicial de los criterios STOPP-START en España desde su aparición, con la intención de fomentar su utilización e investigación en los distintos niveles asistenciales (AU)

Inappropriate use of drugs in older patients may have an adverse impact on several individual health outcomes, such as increasing the prevalence of adverse drug reactions, morbidity and mortality, and geriatric syndromes, as well as on health care systems, such as increased costs and longer hospital stays. Explicit criteria of drug appropriateness are increasingly used to detect and prevent inappropriate use of drugs, either within a comprehensive geriatric assessment or as tool used by different multidisciplinary geriatric teams. STOPP-START criteria, first published in 2008 (in Spanish in 2009), are being adopted as reference criteria throughout Europe. The Spanish version of the new 2014 edition (recently published in English) of the STOPP-START criteria is presented here. A review of all the papers published in Spain using the former version of these criteria is also presented, with the intention of promoting their use and for research in different health care levels (AU)

Impacto de las alertas interactivas modales en la prescripción informatizada de ácido valproico y meropenem / Effect of modal computer-based alerts on the prescription of valproic acid and meropenem

Objetivo: Analizar el impacto de las alertas interactivas modales en la incidencia de la prescripción concomitante de ácido valproico (AVP) y meropenem. Material y método: Estudio analítico de intervención desarrollado en un hospital de tercer nivel de 11 meses de duración. Se seleccionaron aquellos pacientes ingresados con diagnóstico de epilepsia y en tratamiento con AVP y meropenem de forma concomitante. En el sistema de prescripción electrónica asistida se incluyó una alerta modal para que avisase al médico cuando se prescribiese de forma conjunta el AVP y meropenem. Para medir el impacto de esta alerta se compararon los resultados obtenidos con los de un periodo anterior en el que la alerta era no modal. Resultados: El número de pacientes en tratamiento concomitante con AVP y meropenen disminuyó de 13 a 4 pacientes (p = 0,046). Sin embargo, disminuyeron el número de peticiones de niveles de AVP y aumentó el número medio de días conjuntos de prescripción de 4,7 a 8,75. Conclusiones: La implementación de alertas modales disminuye la exposición de los pacientes al tratamiento concomitante de meropenem y AVP (AU)

Objective: To analyze the effect of modal computer-based alerts on the concomitant prescription of valproic acid (VPA) and meropenem. Material and method: Analytical intervention study conducted in a tertiary hospital for eleven months. Hospitalized patients with a diagnosis of epilepsy and treated with VPA and meropenem in concomitant therapy were included. In the computerized prescription order entry software an automatic non-modal alert was reconverted to a modal one. This was triggered when the physician introduced VPA and meropenem together in the same prescription. To measure the effect of this alert the prescription habits were compared with a previous period in which the alert was not modal. Results: Modal computer-based alert modified the prescription habit by reducing the number of patients with concomitant treatment from 13 to 4 (P = 0.046). However, it was notable that the number of requests for VPA serum levels decreased, and the average number of concomitant days of treatment rose from 4.7 to 8.75 in those patients in which none of the drugs was suspended. Conclusions: The implementation of modal computer-based alerts reduces patient exposure to concomitant treatment with meropenem and VPA (AU)

Analisis modal de fallos y efectos del proceso de prescripcion, validacion y dispensacion de medicamentos / Failure modes and effects analysis in the prescription, validation and dispensing process

Objetivo Aplicacion de un analisis modal de fallos y efectos al proceso de prescripcion, validacion y dispensacion de medicamentos en pacientes hospitalizados. Metodos Un grupo de trabajo analizo los pasos que componian el proceso desde la prescripcion medica hasta la dispensacion, identificandose los mas criticos y estableciendo los modos potenciales de fallo que podrian producir un error. Se analizaron posibles causas, sus efectos potenciales y los sistemas de control existentes para prevenir su aparicion. Se calculo el Hazard Score, seleccionandose los que tenian una puntuacion (..) (AU)

Objective To apply a failure modes and effects analysis to the prescription, validation and dispensing process for hospitalised patients. Methods A work group analysed all of the stages included in the process from prescription to dispensing, identifying the most critical errors and establishing potential failure modes which could produce a mistake. The possible causes, their potential effects, and the existing control systems were analysed to try and stop them from developing. The Hazard Score was calculated, choosing those that were ≥ 8, and a Severity Index = 4 was selected independently of the hazard Score value. Corrective measures and an implementation plan were proposed. Results A flow diagram that describes the whole process was obtained. A risk analysis was conducted of the chosen critical points, indicating: failure mode, cause, effect, severity, probability, Hazard Score, suggested preventative measure and strategy to achieve so. Failure modes chosen: Prescription on the nurse's form; progress or treatment order (paper); Prescription to incorrect patient; Transcription error by nursing staff and pharmacist; Error preparing the trolley. Conclusions By applying a failure modes and effects analysis to the prescription, validation and dispensing process, we have been able to identify critical aspects, the stages in which errors may occur and the causes. It has allowed us to analyse the effects on the safety of the process, and establish measures to prevent or reduce them (AU)

Análisis de la interacción ácido valproico-meropenem en pacientes hospitalizados / Analysis of the valproic acid-meropenem interaction in hospitalised patients

Introducción: Existen referencias en la literatura acerca de la gravedad de la interacción entre el ácido valproico y el meropenem. Sin embargo, las recomendaciones en cuanto a su manejo son contradictorias, recomendándose en algunos estudios la monitorización más estrecha del antiepiléptico si se emplean juntos y en otros contraindicando su uso concomitante. El objetivo de este trabajo es analizar la interacción entre el ácido valproico y el meropenem y evaluar el impacto de la intervención farmacéutica sobre la utilización de estos fármacos en pacientes hospitalizados. Material y métodos: Estudio de la prescripción concomitante de ácido valproico y meropenem en un hospital de tercer nivel de 1.080 camas dividido en dos periodos: uno retrospectivo y observacional, el otro prospectivo y con intervención farmacéutica. Se compararon los hábitos de prescripción entre ambos periodos. Resultados: Un total de 26 pacientes recibieron ácido valproico y meropenem simultáneamente (13 en cada periodo), no alcanzando ninguno niveles terapéuticos del antiepiléptico durante el tratamiento. La intervención farmacéutica cambió los hábitos de prescripción, disminuyendo a la mitad los días de tratamiento concomitante, cambiando la antibioterapia y/o monitorizando más estrechamente el antiepiléptico. Conclusiones: La interacción entre el ácido valproico y el meropenem es grave, especialmente por la rapidez con la que disminuyen los niveles del antiepiléptico. Se debe evitar el uso concomitante de ambos fármacos, sustituyendo la antibioterapia de manera empírica o según los patrones de resistencia del microorganismo para mantener el mismo tratamiento anticomicial (AU)

Introduction: Published data demonstrate a serious interaction between valproic acid and meropenem. However, recommendations about the management of concomitant treatment are contradictory; some experts recommend closer monitoring of valproic acid serum concentrations and others recommend avoiding concurrent therapy. The purpose of this study is to critically analyse the interaction and to evaluate the impact of pharmaceutical intervention in the use of these drugs in hospitalised patients. Material and methods: Study of the concomitant prescription of valproic acid and meropenem in a general hospital of 1,080 beds divided in to two periods; the first period was retrospective and observational and it was followed by a prospective period involving pharmaceutical intervention. The prescription habits between both periods were compared. Results: A total of 26 patients received concurrent treatment with valproic acid and meropenem (13 per period) and none of them maintained therapeutic serum levels of the antiepileptic drug. Pharmaceutical intervention modified prescription habits, reducing by half the number of days of concomitant treatment, changing the antibiotherapy and/or monitoring serum concentrations more often. Conclusions: The interaction between valproic acid and meropenem is serious, especially because of the dramatic decrease in the antiepileptic serum concentrations. The concomitant use of both drugs should be avoided, replacing the antibiotherapy empirically, or according to the resistance profiles of the microorganism and maintaining the same the anti-epileptic treatment (AU)