Influencia de la pandemia COVID-19 en la tasa de vacunación antigripal / Impact of the COVID-19 pandemic on the flu vaccination

Introducción: En la temporada 2020-2021 se realizaron campañas mayores de vacunación antigripal, primordialmente en pacientes inmunocomprometidos y sus convivientes. Objetivos: Principal: determinar el impacto de la pandemia COVID-19 en la tasa de vacunación antigripal en la temporada 2020-2021 en pacientes con patologías con carácter inmunosupresor, pacientes pertenecientes a grupos de riesgo y las personas convivientes. Secundarios: porcentaje de vacunas administradas, incidencia de infección del virus de la gripe y la influencia del Servicio de Farmacia sobre la decisión de los pacientes a vacunarse. Metodología: Estudio observacional, prospectivo, de ocho meses de duración, realizado en un hospital comarcal de 125 camas, en pacientes con patologías con carácter inmunosupresor y pacientes que solicitaban la vacunación y estaban incluidos en los grupos de riesgo. Resultados: En la campaña de vacunación 2020-2021 hubo un aumento de pacientes vacunados en un 44,1% (89) con respecto a la vacunación 2019-2020. En el 2019-2020 el 5,3% (6/113) presentaron cuadro de gripe y de los que no recibieron la vacuna el 7,9% (7/89). En la campaña 2020-2021 ningún paciente presentó cuadro de gripe, el 56,4% (114/202) de los pacientes refirieron que fueron influenciados por el servicio de farmacia para vacunarse. Conclusiones: La pandemia por COVID-19 aumentó las tasas de vacunación antigripal en la temporada 2020-2021 ayudando a disminuir la mortalidad en pacientes que sufrieron la enfermedad por la COVID-19. El Servicio de Farmacia influyó positivamente en la tasa de vacunación. (AU)

Introduction: In the 2020-2021 season larger vaccination campaigns were carried out, primarily in immunocompromised patients and their partners. Objectives: Primary end point: determine the impact of the COVID-19 pandemic on the influenza vaccination rate in the 2020-2021 season, in patients with immunosuppressive pathologies, people living with risk groups and patients who requested it and belonged to risk groups. Secondary end point: percentage of vaccines administered, incidence of influenza virus infection and the influence of the Pharmacy Service on the decision of patients to be vaccinated. Methodology: An eight-month prospective, observational study conducted in a 125-bed regional hospital in patients with immunosuppressive pathologies and patients who requested vaccination and were included in risk groups. Results: In the 2020-2021 vaccination campaign, there was an increase in vaccinated patients by 44.1% (89 patients) compared to the 2019-2020 vaccination. In 2019-2020 5.3% (6/113) presented flu symptoms and of those who did not receive the vaccine 7.9% (7/89). In the 2020-2021 campaign, no patient had flu symptoms, 56.4% (114/202) of the patients reported that their decision to get vaccinated was because it was offered at the hospital pharmacy. Conclusions: The COVID-19 pandemic increased flu vaccination rates in the 2020-2021 season, causing lower mortality in patients who suffered from the COVID-19 disease. The Pharmacy Service positively influenced the vaccination rate. (AU)

Acceso a medicamentos huérfanos para el tratamiento de la atrofia muscular espinal en España / Access to orphan drugs for the treatment of spinal muscular atrophy in Spain

Introducción: La atrofia muscular espinal (AME) es una enfermedad rara cuyo diagnóstico y tratamiento es complejo. En España hay dos medicamentos huérfanos financiados por el Sistema Nacional de Salud, nusinersén y onasemnogén abeparvovec, y un tercero, risdiplam, pendiente. El objetivo fue analizar el acceso a los fármacos modificadores de la AME y detectar posibles causas de inequidad. Materiales y método: Estudio descriptivo realizado en dos fases: revisión bibliográfica y entrevistas semiestructuradas a expertos clínicos en AME de las comunidades autónomas (CC. AA.) de Andalucía, Castilla-La Mancha, Cataluña y Murcia. Resultados: El número de centros, servicios o unidades de referencia, la disponibilidad de planes autonómicos para enfermedades raras y los programas piloto de cribado neonatal pueden modular el acceso a los nuevos tratamientos farmacológicos. El número de nuevos pacientes diagnosticados al año se estimó entre uno y seis en cada una de las CC. AA. estudiadas. Dos de las cuatro CC. AA. estaban participando en ensayos clínicos. El tiempo desde la prescripción a la administración de nusinersén estaba entre siete y 60 días. Sólo Cataluña comunicó experiencia con onasemnogén abeparvovec a 30 de junio de 2022. Dos CC. AA. de las cuatro estudiadas disponen de plan autonómico para enfermedades raras; no obstante, se identificó como relevante para el tratamiento de la AME sólo en una de ellas. Conclusiones: No se identificaron diferencias importantes en el acceso al nusinersén en las CC. AA. estudiadas. El diagnóstico de la AME requiere personal clínico experto y centros especializados para iniciar precozmente los tratamientos modificadores de la enfermedad.(AU)

Introduction: Spinal muscular atrophy (SMA) is a rare disease whose diagnosis and treatment are complex. In Spain, there are two orphan medicines that are currently financed by the state, nusinersen and onasemnogene abeparvovec and, a third in process, risdiplam. The objective was to detect possible causes of inequity in the diagnosis and treatment of SMA in Spain. Materials and method: Descriptive study realized in two phases: a first phase of bibliographic revision and a second phase of semi-structured interviews with clinical experts in SMA in Andalusia, Castilla-La Mancha, Catalonia and Murcia. Results: The number of centers, services or units of reference, the availability of regional autonomous plans for rare diseases and pilot programs of neonatal screenings can regulate access to treatments. The number of new patients diagnosed per year is estimated between one and six in the four autonomous communities (ACs) of Spain studied. Differences were not found in logistical resources. Two of the four ACs studied have regional autonomous plans for rare diseases, however, their utility has only had relevance in one of two of the ACs. Conclusions: Important differences in access to nusinersen were not identified in the studied ACs The diagnosis of SMA requires clinical specialized experts and specialized centers for early intervention of disease-modifying therapies.(AU)

[Access to orphan drugs for the treatment of spinal muscular atrophy in Spain]. / Acceso a medicamentos huérfanos para el tratamiento de la atrofia muscular espinal en España.

INTRODUCTION: Spinal muscular atrophy (SMA) is a rare disease whose diagnosis and treatment are complex. In Spain, there are two orphan medicines that are currently financed by the state, nusinersen and onasemnogene abeparvovec and, a third in process, risdiplam. The objective was to detect possible causes of inequity in the diagnosis and treatment of SMA in Spain. MATERIALS AND METHOD: Descriptive study realized in two phases: a first phase of bibliographic revision and a second phase of semi-structured interviews with clinical experts in SMA in Andalusia, Castilla-La Mancha, Catalonia and Murcia. RESULTS: The number of centers, services or units of reference, the availability of regional autonomous plans for rare diseases and pilot programs of neonatal screenings can regulate access to treatments. The number of new patients diagnosed per year is estimated between one and six in the four autonomous communities (ACs) of Spain studied. Differences were not found in logistical resources. Two of the four ACs studied have regional autonomous plans for rare diseases, however, their utility has only had relevance in one of two of the ACs. CONCLUSIONS: Important differences in access to nusinersen were not identified in the studied ACs The diagnosis of SMA requires clinical specialized experts and specialized centers for early intervention of disease-modifying therapies.

TITLE: Acceso a medicamentos huérfanos para el tratamiento de la atrofia muscular espinal en España.Introducción. La atrofia muscular espinal (AME) es una enfermedad rara cuyo diagnóstico y tratamiento es complejo. En España hay dos medicamentos huérfanos financiados por el Sistema Nacional de Salud, nusinersén y onasemnogén abeparvovec, y un tercero, risdiplam, pendiente. El objetivo fue analizar el acceso a los fármacos modificadores de la AME y detectar posibles causas de inequidad. Materiales y método. Estudio descriptivo realizado en dos fases: revisión bibliográfica y entrevistas semiestructuradas a expertos clínicos en AME de las comunidades autónomas (CC. AA.) de Andalucía, Castilla-La Mancha, Cataluña y Murcia. Resultados. El número de centros, servicios o unidades de referencia, la disponibilidad de planes autonómicos para enfermedades raras y los programas piloto de cribado neonatal pueden modular el acceso a los nuevos tratamientos farmacológicos. El número de nuevos pacientes diagnosticados al año se estimó entre uno y seis en cada una de las CC. AA. estudiadas. Dos de las cuatro CC. AA. estaban participando en ensayos clínicos. El tiempo desde la prescripción a la administración de nusinersén estaba entre siete y 60 días. Sólo Cataluña comunicó experiencia con onasemnogén abeparvovec a 30 de junio de 2022. Dos CC. AA. de las cuatro estudiadas disponen de plan autonómico para enfermedades raras; no obstante, se identificó como relevante para el tratamiento de la AME sólo en una de ellas. Conclusiones. No se identificaron diferencias importantes en el acceso al nusinersén en las CC. AA. estudiadas. El diagnóstico de la AME requiere personal clínico experto y centros especializados para iniciar precozmente los tratamientos modificadores de la enfermedad.

Sistemas personalizados de dosificación: una herramienta para la práctica profesional sanitaria en la atención farmacéutica / Personalized Dosification Systems: a tool for the professional sanitary pharmaceutical practice in the pharmaceutical attention

A finales del año 2010, estaba finalizando el plazo que el Gobierno de España se había marcado para conseguir adecuar las cantidades (dosis) de medicamentos dispensadas al paciente a las prescripciones que éstos habían recibido y así implantar lo que correctamente debería denominarse sistemas de dosis unitarias para dispensación. Así, han surgido algunas opiniones, incluso sorprendentemente desde el ámbito farmacéutico, contrarias a una práctica bastante extendida como es el uso de los conocidos como sistemas personalizados de dosificación (SPD), que el farmacéutico realiza después del acto de la dispensación y con la autorización expresa del paciente. Para nosotros, el uso de los SPD supone para los farmacéuticos una muy limitada inversión económica en material y utillaje, una pequeña aunque necesaria formación y acreditación, y un considerable incremento en la adquisición de responsabilidad y recuperación de prestigio social; esto último derivado de que suponen unas ventajas indiscutibles para los pacientes y los propios Sistemas de Salud. Consecuentemente, aportamos nuestras experiencias positivas al haber demostrado científicamente la hermeticidad de un sistema SPD (Anota®) y la estabilidad química de omeprazol (genérico en cápsulas, 20 mg) y enalapril (genérico en comprimidos, 20 mg), ambos de Laboratorios Mylan, durante un tiempo muy superior a previsto para el uso del SPD (AU)

At the end of the year 2010, the deadline that the Government of Spain had given to be able to adequate the amounts of (doses) of medicines were finishing. Dispensed to the patient to the prescriptions that had been received and so successfully implement what should be called the Unit Dose Systems for dispensing. Like that, there have been some opinions, even with surprise from the pharmaceutical field, contrary to a fairly widespread practice as the use of so-called Personalized Dosification Systems (PDS), which the pharmacist made after the act of dispensing with the express consent of the patient. For us, the use of PDS means a very limited economic investment in equipment and tools for the pharmacists, a small but necessary training and accreditation, and a considerable increase in the acquisition of liability and recovery of social prestige; the latter derived from PDS represent clear benefits for patients and health system. Consequently, we provide our positive experiences having shown scientifically the air tightness of a PDS system (Anota®) and the chemical stability of omeprazole (Generic capsules, 20 mg) and enalapril (Generic tablets, 20 mg), both of Mylan Laboratories, for a while much higher than expected for the use of PDS (AU)

[Dose intensity received in breast cancer treatment with chemotherapy]. / Intensidad de dosis recibida en el tratamiento quimioterápico del cáncer de mama.

OBJECTIVE: To know relative dose intensity (RDI) in patients with breast cancer treated with chemotherapy. To determine the number of patients where RDI was < 85% of that programmed and the possible cause. METHOD: Retrospective study, four-month selection period. The following were recorded: age, body surface, protocol applied, intention of treatment, frequency of administration of cycles, number of cytostatic treatments previously received and filgrastim administration. The average RDI per patient and protocol was calculated. RESULTS: 110 patients were analysed, the average age of them being 55.4 years (interval: 31-84), average body surface 1.7 m2 (1.3-2.4). Overall average RDI was 91.0% (SD 10.7). 93.8% (10.6), 95.8% (6.3) and 81.9% (18.5) in neoadjuvant, adjuvant and palliative treatments, respectively. 20% of the patients did not reach a RDI = 85% of that programmed, average RDI 69.5% (3.29). A delay in the administration of chemotherapy equal or greater than seven days occurred in 45.4% of the cases, average RDI 80.7% (16.0). In the episodes where the dose was reduced because of toxicity, the RDI was 75.6% (13.6). Significant inverse ratios were obtained with age (p = 0.02) and line of treatment (p = 0.03) with the RDI. In 36.8%, dose reduction was caused by neutropenia; 52.9% received filgrastim. CONCLUSIONS: Most patients received the appropriate RDI. Age, previous treatments and intention of treatment were the variables with the greatest impact on the dose received. The delay in administering the cycle was the most frequent act minimising the toxicity and which least affected the treatment.

[Budget impact analysis of the treatment of chronic hepatitis C in a hospital]. / Análisis de impacto presupuestario en el tratamiento de la hepatitis por virus C en un hospital.

OBJECTIVE: To perform a budget impact analysis (BIA) of the treatment with pegylated interferon (pegIFN), alfa-2a or alfa-2b, plus ribavirin in patients with chronic hepatitis C (CHC). METHOD: An interactive model has been designed from the inputs obtained from hospital databases. Prices for pegIFN and RIB have been taken from the hospitals considering their respective discounts. Only pharmacological costs (euros 2005 values) for the options have been considered. Both strategies have been considered as therapeutic equivalents. RESULTS: The number of patients with CHC evaluated in the model has been of 117, with an average age of 42 years and an average weight of 75 kg. The genotypes of the patients were: G1/4, 85% and; G2/3, 15%. Discontinuation of the treatment at week 12 took place in 26% of the patients. The average duration of treatment has been of 37 weeks. Total cost of the 117 evaluated patients ranged between 942,632-952,109 and 861,646-880,751 euros for the treatment with pegIFN alfa-2a + RIB and pegIFN alfa-2b + RIB, respectively. CONCLUSIONS: BIA models can be useful for the inclusion or reassessment of drugs in formularies. In this case, the treatment with pegIFN alfa-2b + RIB (in comparison with pegIFN alfa-2a + RIB) is an efficient strategy although it depends on acquisition prices, and so, it would be rarely useful in other centres. In our hospital it would produce a budgetary saving that would range from 71,358 to 80,986 euros, which would represent a 7.5-8.6% of the total cost of the pharmacological treatment of the CHC.

Análisis de impacto presupuestario en el tratamiento de la hepatitis por virus C en un hospital / No disponible

Objetivo: Realizar un análisis de impacto presupuestario (AIP)del tratamiento con interferón pegilado (pegIFN), alfa-2a o alfa-2b, más ribavirina (RIB) en pacientes naïve con hepatitis crónicaC (HCC).Método: Se ha diseñado un modelo interactivo a partir de lasvariables obtenidas de bases de datos hospitalarias. Los precios depegIFN y RIB han sido los abonados por el hospital con sus respectivosdescuentos. Sólo se han considerado los costes farmacológicosasociados a las opciones (en euros 2005). Ambas estrategiasse han considerado equivalentes terapéuticos.Resultados: El número de pacientes con HCC evaluados enel modelo ha sido de 117, con una edad media de 42 años y unpeso promedio de 75 kg. Los genotipos de los pacientes y su distribuciónfueron: G1/4, 85% y G2/3, 15%. Se produjo discontinuacióndel tratamiento a las 12 semanas en el 26% de lospacientes. El tiempo promedio del tratamiento ha sido de 37semanas. El coste total de los 117 pacientes evaluados oscilaentre 942.632-952.109 y 861.646-880.751 euros para el tratamientocon pegIFN alfa-2a + RIB y con pegIFN alfa-2b + RIB,respectivamente.Conclusiones: Los modelos de AIP pueden ser útiles para lainclusión o reevaluación de medicamentos en las guías farmacoterapéuticas.En este hospital, el tratamiento con pegIFN alfa-2b +RIB (en comparación con pegIFN alfa-2a + RIB) es una estrategiaeficiente aunque muy sensible a los precios de adquisición por loque es difícilmente extrapolable a otros entornos. En nuestro hospitalproduciría un ahorro presupuestario entre 71.358 a 80.986euros, lo que representaría un 7,5-8,6% del coste total del tratamientofarmacológico de la HCC

Objective: To perform a budget impact analysis (BIA) of thetreatment with pegylated interferon (pegIFN), alfa-2a or alfa-2b,plus ribavirin in patients with chronic hepatitis C (CHC).Method: An interactive model has been designed from theinputs obtained from hospital databases. Prices for pegIFN andRIB have been taken from the hospitals considering their respectivediscounts. Only pharmacological costs (euros 2005 values) forthe options have been considered. Both strategies have been consideredas therapeutic equivalents.Results: The number of patients with CHC evaluated in themodel has been of 117, with an average age of 42 years and anaverage weight of 75 kg. The genotypes of the patients were:G1/4, 85% and; G2/3, 15%. Discontinuation of the treatment atweek 12 took place in 26% of the patients. The average durationof treatment has been of 37 weeks. Total cost of the 117 evaluatedpatients ranged between 942,632-952,109 and 861,646-880,751 euros for the treatment with pegIFN alfa-2a + RIB andpegIFN alfa-2b + RIB, respectively.Conclusions: BIA models can be useful for the inclusion orreassessment of drugs in formularies. In this case, the treatmentwith pegIFN alfa-2b + RIB (in comparison with pegIFN alfa-2a +RIB) is an efficient strategy although it depends on acquisitionprices, and so, it would be rarely useful in other centres. In ourhospital it would produce a budgetary saving that would rangefrom 71,358 to 80,986 euros, which would represent a 7,5-8,6%of the total cost of the pharmacological treatment of the CHC

[How to increase the involvement of casualty patients in their treatments: efficacy of some informative posters]. / Cómo aumentar la implicación del paciente de urgencias en su tratamiento? Eficacia de unos pósters informativos.

OBJECTIVE: To determine whether posters/leaflets increase doctors' information on the allergies and on the medication their patients are taking and patients' understanding of their treatment. DESIGN: First stage: multi-centre transversal descriptive study. Second stage: intervention with control and without randomisation. SETTING: Primary care medical emergency services (MES). PARTICIPANTS: MES patients under prescribed drug treatment. INTERVENTIONS: Use of posters/leaflets. MAIN MEASUREMENTS: 1) Proportion of patients for whom the doctor was ignorant of allergies to drugs or of accompanying medication. 2) Proportion of prescriptions in which patients understood the dosage of the medication prescribed. SOURCE: ad hoc questionnaire to patients. ANALYSIS: chi2 test (category variables). In some cases, the Breslow-Day and Tarone tests were conducted. RESULTS: Total patients included, 1233; 1766 prescriptions analysed; 53.4% women. Mean age: 29+/-18 years old. 1) Doctor's understanding of accompanying medication: at the second stage, drop of 25.5% (95% CI, 33.5-17.5) for intervention group versus drop of 12.5% (95% CI, 19.8-5.2) for control group, in the number of patients for whom the doctor did not know the medication (P=.024). 2) Patient's understanding of dosage: at the second stage, increase of 16.8% (95% CI, 9.8-23.8) for intervention group, versus a decrease of 1% in control group, in the medicines whose dosage the patient was aware of (P<.001). CONCLUSIONS: The dissemination of posters/leaflets was effective in increasing patients' knowledge of their medication's dosage and doctors' understanding of questions affecting prescription.

¿Cómo aumentar la implicación del paciente de urgencias en su tratamiento?: eficacia de unos pósters informativos / How to increase the involvement of casualty patients in their treatments: efficacy of some informative posters

Objetivo. Determinar si unos pósters/folletos aumentan la información del médico sobre las alergias a la medicación que están tomando los pacientes y la comprensión del tratamiento por parte de éstos. Diseño. Primera fase: descriptivo, transversal, multicéntrico. Segunda fase: de intervención, controlado, sin aleatorización. Emplazamiento. Servicios de urgencias médicas no hospitalarios (SUM). Participantes. Pacientes del SUM con tratamiento farmacológico prescrito. Intervenciones. Difusión de los pósters/folletos. Mediciones principales. La proporción de pacientes de los que el médico no conocía la alergias a medicamentos o la medicación concomitante, y la proporción de prescripciones en las que el paciente conocía la posología del fármaco recetado. Fuente: cuestionario ad hoc realizado a los pacientes. Análisis: test de la *2 (variables categóricas). En algunos casos se efectuó la prueba de Breslow-Day y Tarone. Resultados. Se incluyó a un total de 1.233 pacientes; se analizaron 1.766 prescripciones; el 53,4% eran mujeres y la edad media era de 29 ± 18 años. 1. Desconocimiento de la medicación concomitante por parte del médico: en la segunda fase, disminución del 25,5% (intervalo de confianza [IC] del 95%, 33,5-17,5) en el grupo de intervención frente al 12,5% (IC del 95%, 19,8-5,2) en el grupo control del número de pacientes en que el médico desconocía esta medicación (p = 0,024) 2. Conocimiento de la posología por parte del paciente: en la segunda fase, incremento del 16,8% (IC del 95%, 9,8-23,8) en el grupo de intervención frente a un decremento del 1% en el grupo control del número de prescripciones en que el paciente conocía la posología (p < 0,001). Conclusiones. La difusión de pósters/folletos dirigidos a los pacientes fue eficaz para incrementar el conocimiento sobre la posología de su medicación y para que el médico conociera más la medicación concomitante a su prescripción

Objective. To determine whether posters/leaflets increase doctors' information on the allergies and on the medication their patients are taking and patients' understanding of their treatment. Design. First stage: multi-centre transversal descriptive study. Second stage: intervention with control and without randomisation. Setting. Primary care medical emergency services (MES). Participants. MES patients under prescribed drug treatment. Interventions. Use of posters/leaflets. Main measurements. 1) Proportion of patients for whom the doctor was ignorant of allergies to drugs or of accompanying medication. 2) Proportion of prescriptions in which patients understood the dosage of the medication prescribed. Source: ad hoc questionnaire to patients. Analysis: *2 test (category variables). In some cases, the Breslow-Day and Tarone tests were conducted. Results. Total patients included, 1233; 1766 prescriptions analysed; 53.4% women. Mean age: 29±18 years old. 1) Doctor's understanding of accompanying medication: at the second stage, drop of 25.5% (95% CI, 33.5-17.5) for intervention group versus drop of 12.5% (95% CI, 19.8-5.2) for control group, in the number of patients for whom the doctor did not know the medication (P=.024). 2) Patient's understanding of dosage: at the second stage, increase of 16.8% (95% CI, 9.8-23.8) for intervention group, versus a decrease of 1% in control group, in the medicines whose dosage the patient was aware of (P<.001). Conclusions. The dissemination of posters/leaflets was effective in increasing patients' knowledge of their medication's dosage and doctors' understanding of questions affecting prescription

[Nutrient absorption rate from the peritoneal cavity in rats]. / Velocidad de absorción de nutrientes desde la cavidad peritoneal de ratas.

A study has been done of the absorption/elimination kinetics of nutritive substances such as glucose, amino acids and fats from the peritoneal cavity. For this purpose, 48 male Wistar rats were administered an intravenous or intraperitoneal "bolus" of 2 microCi of L-glucose-C14/250 g of body weight, 3 microCi of D-alanine-L-C14/250 g and 0.4 g of Intralipid/250 g body weight. A two-compartment pharmacokinetic model was applied to determine the absorption, elimination and distribution constants among the different body compartments of each of these substrates, as well as the absorption and elimination halflife. When the areas under the curves were compared following intravenous and intraperitoneal infusion, the total physiological availability or fraction of dose absorbed over a given period of time were calculated. A higher absorption and elimination constant for glucose and amino acids as compared to fats was found. Higher than 90% absorption for all substrates was found, but since in the case of fats the elimination constant is lower and longer the elimination halflife, we must be cautious regarding its infusion rate.

Urinary excretion kinetics of p-nitrophenol following oral administration of parathion in the rabbit.

The urinary excretion kinetics of p-nitrophenol were studied in rabbits following oral administration of parathion at a dose of 3 mg/kg. Elimination of p-nitrophenol began rapidly, and of the total amount excreted during the study period, 46% was excreted in the first 3 h; 85% was excreted at 6 h after administration of the pesticide. The mean maximum excretion rate of p-nitrophenol was 111.15 +/- 61.02 micrograms/h reached in a time of 0.77 +/- 0.26 h. The formation and disappearance rate constants of the metabolite were 2.85 +/- 2.80 h-1 and 0.80 +/- 0.28 h-1, respectively. A linear relationship was observed between the plasma concentrations of parathion and the urinary excretion rate of p-nitrophenol.

Toxicokinetics of parathion in the rabbit.

The plasma kinetics of parathion were studied in rabbits after i.v. administration of a dose of 1.5 mg/kg and oral administration of 3 mg/kg. The time course of parathion plasma levels administered intravenously followed a three-compartment kinetic model statistically, whereas when administration was oral, the optimum kinetic model proved to be two-compartmental. The process of the absorption of parathion is very fast with a mean value for the absorption constant (ka) of 33 +/- 15.41 h-1. The slow disposition half-lives for i.v. and oral administration had mean values of 5.08 +/- 3.08 and 1.08 +/- 0.27 h, respectively. From the values established for the parameters defining the distribution process the wide accessibility of parathion to the different body organs and tissues may be seen. Although the compound has a high elimination constant, this process is not limiting to distribution.