Background: Levetiracetam (LEV) is a second-generation antiepileptic drug extensively used in therapeutics. The aim of this study was to evaluate the influence that sex, age, and weight exert on LEV pharmacokinetics in clinical practice. Methods: We conducted a 6-year retrospective observational study. Patients were classified in subgroups according to sex, weight (normal range, overweight, and obese), and age (young adult: 16-30 years old, middle-aged adult: 31-50 years old, advanced adult: 51-64 years old, and elderly adult: >= 65 years old). We compared LEV apparent oral clearance (LEV CL/F) between the subgroups. Results: A total of 238 LEV basal serum concentrations (LEV C-0) corresponding to 156 patients were identified. Significant differences were observed in LEV CL/F between males and females when LEV CL/F was expressed as L/h [mean (SD): 4.79 (1.84) L/h in males versus 4.13 (1.64) L/h in females; P < 0.001]. These differences were not significant when LEV CL/F was normalized by weight [mean (SD): 60.64 (24.90) mL/h/kg in males versus 64.10 (28.87) mL/h/kg in females; n. s.]. Weight in females was 17% lower compared with males. A progressive reduction in LEV CL/F was observed with increasing age, in a proportion that was similar to the decline in renal function. The elderly patients presented 30% lower LEV CL/F (mL/h/kg) and 43% lower creatinine clearance (CCr) in comparison with adults. No statistically significant differences were observed in LEV CL/F calculated in L/h between weight subgroups. However, when LEV CL/F was expressed in mL/h/kg, a progressive reduction was observed [normal weight: 72.21 (28.97); overweight: 57.84 (25.38); obese: 49.45 (14.50); P < 0.001]. A significant and positive correlation between CCr and LEV CL/F was observed, confirming the important role of the renal function in LEV CL/F. The CCr increased in each sex group when weight increased; however, LEV CL/F (L/h) remained constant. Conclusions: Sex, age, and weight affect LEV pharmacokinetics, having an impact on the individual dosage regimen needed to achieve the therapeutic objective. Sex is a conditioning factor of LEV CL/F, although its influence is principally due to the weight. LEV CL/F decreases with advancing age, proportionally to the decline in renal function. It is confirmed that LEV dosage per body weight is not required, and prescribing higher doses of LEV in obese patients is not justified. These data suggest that routine LEV therapeutic drug monitoring in the elderly patients, patients with renal dysfunction, and obese patients is indicated.

A 52-year-old man developed tinnitus and hearing loss after receiving high doses of oral morphine sulfate. His hearing loss did not fully resolve after the discontinuation of morphine, and he required the use of hearing aids.

Objective: to determine the incidence of linezolid-induced haematological toxicity and study the influence of renal clearance on its appearance and the preventive effect of pyridoxine. Methods: a retrospective observational study was conducted. Every patient treated with linezolid in a university hospital during 6 months was included. Haematological toxicity was defined as a decrease of 25% in hemoglobin, of 25% in platelets and/or 50% in neutrophils from baseline. The incidence of haematological toxicity and the percentage decrease in analytical variables were compared in patients with and without renal failure (creatinine clearance lower than 50 mL/min), using the 30 mL/min threshold, and with or without pyridoxine; using Chi -Square and U Mann-Whitney tests, respectively. Results: thirty-eight patients were evaluated. Sixteen (42%) presented haematological toxicity (2 due to a decrease in haemoglobin, 9 in platelets and 8 in neutrophils). Two patients (5%) discontinued treatment due to thrombocytopenia. Toxicity incidence was similar in patients with and without renal failure, 42% vs 42%, p = 0.970, with more or less than 30 ml/min, 67% vs 40%, p = 0.369, or with or without pyridoxine, 47.8% vs 33%, p = 0.376. Patients with renal failure had a significantly greater reduction in platelet count, p = 0.0185. Conclusion: forty-two percent of patients had haematological toxicity, being more frequent platelets and neutrophils reduction. This was not significantly higher in patients with renal failure or in those without pyridoxine. Greater reduction in platelet count was observed in patients with renal failure.

The aim of this study was to develop a user-friendly checklist for critical appraisal of indirect comparisons of drugs, considering clinical, methodological/statistical and quality aspects, mainly to be applied in drug evaluation in the decision-making context. After conducting a review of the literature, we used group consensus to establish the key points of the checklist, focusing mainly on indirect comparisons, but including topics related to network meta-analysis or multiple treatment comparisons. The coordinating group elaborated the first draft, which was reviewed by external experts, re-evaluated by the coordinating group and finally assessed by 23 drug evaluation experts trained in indirect comparisons, who applied the checklist to one study. The Kappa index of agreement was calculated and the final checklist was developed by group consensus including the external experts. The checklist has two parts. The first consists of three eliminatory key questions while the second includes 17 items: 5 regarding quality, 5 regarding clinical issues and 7 dealing with methodology/statistics. The median kappa values of the 23 evaluations were 0.83 (range 0.67-0.93), 0.61 (0.54-0.91) and 0.36 (0.22-1) with regard to quality, clinical aspects and methodology/statistics, respectively. A structured checklist was developed to facilitate critical appraisal of key issues in indirect comparisons, including comments for assessing the consequences of its application to drug evaluation in the decision-making context. Agreement between reviewers in clinical and quality items was good, but weaker in methodology/statistics ones.

Background. Several European governments have recently mandated price cuts in drugs to reduce health care spending. However, such measures without supportive evidence may compromise patient care because manufacturers may withdraw current products or not launch new agents. A value-based pricing scheme may be a better approach for determining a fair drug price and may be a medium for negotiations between the key stakeholders. To demonstrate this approach, pharmacoeconomic (PE) modeling was used from the Spanish health care system perspective to estimate a value-based price for bevacizumab, a drug that provides a 1.4-month survival benefit to patients with metastatic colorectal cancer (mCRC). The threshold used for economic value was three times the Spanish per capita GDP, as recommended by the World Health Organization (WHO).Methods. A PE model was developed to simulate outcomes in mCRC patients receiving chemotherapy ± bevacizumab. Clinical data were obtained from randomized trials and costs from a Spanish hospital. Utility estimates were determined by interviewing 24 Spanish oncology nurses and pharmacists. A price per dose of bevacizumab was then estimated using a target threshold of €78,300 per quality-adjusted life year gained, which is three times the Spanish per capita GDP.Results. For a 1.4-month survival benefit, a price of €342 per dose would be considered cost effective from the Spanish public health care perspective. The price may be increased to €733 or €843 per dose if the drug were able to improve patient quality of life or enhance survival from 1.4 to 3 months.Conclusions. This study demonstrated that a value-based pricing approach using PE modeling and the WHO criteria for economic value is feasible and perhaps a better alternative to government mandated price cuts. The former approach would be a good starting point for opening dialog between European government payers and the pharmaceutical industry.

Objetivo Cuantificar el uso de comparaciones indirectas (CI) en los informes de evaluación de medicamentos publicados en internet por el Grupo de Evaluación de Novedades, Estandarización e Investigación en Selección de Medicamentos (GENESIS). Método Estudio retrospectivo de los informes redactados en 2008-2009. Registro de la existencia de comparadores y características de los estudios comparativos directos e indirectos incluidos. Resultados En el 95% de los 337 informes analizados existe un comparador activo, en el 50% hay un estudio frente a éste. En 114 informes (34%), se referencia una CI, el 69% elaborada por el autor del informe. La mayoría fueron CI narrativas, ninguna ajustada. En los casos sin CI podría haberse realizado en el 16% y era dudoso en el 24%. Conclusiones Muchos medicamentos tienen comparador pero no estudios directos frente a éste, las CI deberían incorporarse en los informes en mayor medida y con criterios de calidad.

OBJECTIVE: To analyse the assessment reports published on the GENESIS webpage (Group for Innovation, Assessment, Standardisation and Research in the Selection of Drugs) and assess the variability of the group's proposals to include drugs in the Formulary. METHOD: We analysed reports published by hospitals on the GENESIS webpage between 2004 and 2007. Data were collected on drugs and indications, ATC group, open or restricted access publications, hospital, and publication date. We drafted a questionnaire that would measure to what extent to what extent the 9-section model recommended by GENESIS was included in each report. For drugs with two or more reports, we analysed whether the recommendation coincided and the possible cause in the event of conflict. RESULTS: We analysed 416 reports corresponding to 185 different drug indications. 93% included 6 or more of the recommended sections, a number which increased over time. The most frequently included sections were: approved indications (92%), mechanism of action (95%), and references (86%) (percentages from 2007). Sections which had an increasing but lower percentage were: differential characteristics (60%), literature search method (40%) and conclusions with a summary of efficacy, safety and cost data (52%). 73% of which had definite recommendations, which coincided for 42 out of the 67 drugs with more than one recommendation report. CONCLUSIONS: The work carried out by the GENESIS group has enabled S

Objetivo Cuantificar la actividad de las Comisiones de Farmacia y Terapéutica (CFyT) con relación a la evaluación y selección de medicamentos, y describir la variabilidad en las decisiones de incorporación de los mismos. Método Estudio descriptivo transversal basado en un cuestionario dirigido a los 513 hospitales españoles con más de 75 camas. Se incluyeron preguntas referidas a las resoluciones de la CFyT, el posicionamiento terapéutico y los informes de evaluación. La selección se realizó entre noviembre de 2007 y enero de 2008. La variabilidad en las conclusiones de las CFyT se expresa en 5 categorías o grados de coincidencia. Resultados Participaron 175 hospitales, tasa de respuesta del 34% (54% de las camas). El número medio de medicamentos-indicación evaluados por hospital fue 10,35 (7,45). La proporción de evaluaciones que concluyen en inclusión o rechazo del fármaco fue del 75,3 y 21,4%, respectivamente. En el 16,2% se concluyó en equivalencia terapéutica. Se establecieron condiciones de uso en un 64%, y se incluyeron en un guía clínica en un 33%. En cuanto a la variabilidad, en el 81,0% de las evaluaciones realizadas se coincide en la conclusión de incluir o de rechazar el medicamento, en el 19,0% se ha tomado la decisión opuesta a la mayoritaria. Conclusiones La actividad de evaluación y selección de medicamentos en los hospitales es considerable. La proporción de medicamentos aprobados es similar en los diferentes tipos de hospital. La variabilidad en la decisión de inclusión es amplia y similar a estudios realizados en otros países. Indican la conveniencia de estandarización de la metodología.

Objective To assess the cost-effectiveness of ranibizumab compared with pegaptanib in the treatment of patients with minimally classic/occult neovascular age-related macular degeneration (AMD), from a societal perspective in Spain. Methods We constructed a Markov model with five states defined by visual acuity (VA) in the better-seeing eye (Snellen scale): VA >20/40, ¿20/40 to >20/80, ¿20/80 to >20/200, ¿20/200 to >20/400, ¿20/400, and an additional death state. Two cohorts of patients were distributed along the VA states, and treated with either ranibizumab or pegaptanib. Transition probabilities assigned for movement between these states with both drugs were obtained from published randomized clinical trials. Medical costs related to AMD treatment and follow-up, medical costs related to AMD comorbidities, and non-medical-related costs were taken into account. Costs (2008 Euro), health outcomes (Quality-adjusted life years¿QALYs), both discounted at a 3.5% annual rate, and incremental cost-effectiveness ratios (ICER: €/QALY), were determined for a lifetime horizon in the base case analysis. Sensitivity analyses were conducted to explore different scenarios and assumptions in the model. Results Treating patients with varying degrees of visual impairment with monthly ranibizumab instead of pegaptanib was €71,206 more costly and provided 2.437 additional QALYs (€29,224/QALY). When administered on an as-needed basis, as in the Prospective Optical Coherence Tomography Imaging of Patients with Neovascular AMD Treated with Intraocular Ranibizumab (PrONTO) trial, the cost per QALY gained with ranibizumab was reduced to €4,623. Conclusions The cost per QALY gained with monthly ranibizumab compared with pegaptanib in the minimally classic/occult neovascular AMD population is just below the €30,000 threshold below which new drugs are sometimes regarded as cost-effective strategies in Spain. In this model, the key variables with greater impact on the cost-effectiveness results were the selected time horizon and the chosen extrapolation method, the source for data on pegaptanib efficacy and the number of ranibizumab injections. When administered on an as-needed basis, ranibizumab was a cost-effective strategy compared to pegaptanib in this population.

Objective: Define the structure and working procedures of the Pharmacy and Therapeutic Committees (P&T Committees) in Spanish hospitals. Setting: Hospitals over 75 beds located in all regions of the Spanish State. Method: A cross-sectional descriptive study based on the completion of a questionnaire that consisted of 138 questions. The participants were recruited by post, e-mail and telephone between November 2007 and January 2008. The Hospitals were classified according to their size and public or private and university or non-university status. Main Outcome Measures: They are related with the structure and composition of the P&T Committees, performance, drug evaluation process, working methods and the results of their activity. Results: A total of 200 hospitals answered the questionnaire (response rate of 39.0% of hospitals and 57.1% of the beds in Spain). All the hospitals have P&T Committees, 99.5% have a Drug Formulary, 71.0% have a Therapeutic Interchange Programme and 91.0% have a document determining the mission, objectives and functions of the P&T Committee. Almost all hospitals (95.5%) have established a formal application for the inclusion of a drug in the hospital, while 80.5% have established a model for evaluation reports. The mean (SD) number of participants in P&T Committees was 11.84 (3.82). The annual mean of drugs evaluated per hospital was 10.35 (7.45). The proportion of assessments that concludes the inclusion, rejection or deferral of the decision was 75.3, 21.4 and 3.2%, respectively. Conclusion: Spanish P&T Committees have a similar structure and function, a multi-disciplinary professional composition to carry out an important assessment activity. This activity is higher in large hospitals and in university hospitals. The proportion of the approved and rejected drugs is similar in different types of hospital. The Therapeutic Interchange Guidelines, the use of application models and the reports follow the indications of scientific collaborative groups, thus being used more in Spain than in other countries.