Tasa de resangrado vítreo posterior a vitrectomía o facovitrectomía en pacientes con retinopatía diabética proliferativa: estudio retrospectivo / Vitreous rebleeding rate after vitrectomy or phacovitrectomy in patients with proliferative diabetic retinopathy: A retrospective study

Antecedentes: La complicación más común tras la vitrectomía en pacientes es el resangrado en cavidad vítrea. Es importante detectar los distintos factores que pueden incrementar la tasa de resangrado vítreo en estos pacientes. Objetivo: Realizar una revisión retrospectiva de la tasa de resangrado de cavidad vítrea posterior a vitrectomía o facovitrectomía. Método: Estudio retrospectivo, descriptivo y comparativo de pacientes con diagnóstico de retinopatía diabética proliferativa con procedimiento de facovitrectomía o vitrectomía. Se obtuvieron datos de antecedentes personales patológicos, tipo de intervención quirúrgica y grado del cirujano que realizó el procedimiento. Resultados: Se revisaron 1.227 expedientes de pacientes diabéticos sometidos a vitrectomía o facovitrectomía. El 65% presentaron hipertensión arterial sistémica. La tasa de filtración glomerular promedio fue del 63,50 (±32,36) ml/min/1,73m2 y la de hemoglobina glucosilada (HbA1c) del 8% (4,6 al 15%). En la comparación de variables se obtuvo una diferencia significativa de la tasa de resangrado vítreo comparando la facovitrectomía con la vitrectomía (p=0,003), y al relacionar la vitrectomía con el resangrado, se obtuvo una razón de momios de 1,44. Conclusión: Los resultados obtenidos muestran una menor tasa de resangrado en los pacientes con retinopatía diabética proliferativa sometidos a facovitrectomía.(AU)

Background: The most common complication after vitrectomy is the rebleeding in vitreous cavity. It is important to detect the different factors that can increase the vitreous rebleeding rate in these patients. Objective: To carry out a retrospective review of the rate of vitreous rebleeding after vitrectomy or phacovitrectomy. Method: Retrospective, descriptive and comparative study of patients with a diagnosis of proliferative diabetic retinopathy with phacovitrectomy or vitrectomy procedure. Personal background data, type of surgical intervention and grade of the surgeon who carried out the procedure were obtained. Results: One thousand two hundred twenty-seven files of diabetic patients with vitrectomy or phacovitrectomy were reviewed. Sixty-five percent presented systemic arterial hypertension. The average glomerular filtration rate was 63.50 (±32.36)ml/min/1.73m2 and glycosylated hemoglobin (HBA1C) of 8% (4.6-15%). In the comparison of variables, a significant difference in the rate of vitreous rebleeding was obtained comparing phacovitrectomy with vitrectomy (P=.003), in the relationship between vitrectomy with vitreous rebleeding, an odds ratio of 1.44 was obtained. Conclusion: The results obtained show a lower rate of rebleeding in patients undergoing phacovitrectomy in patients with proliferative diabetic retinopathy.(AU)

Vitreous rebleeding rate after vitrectomy or phacovitrectomy in patients with proliferative diabetic retinopathy: A retrospective study.

BACKGROUND: The most common complication after vitrectomy is the rebleeding in vitreous cavity. It is important to detect the different factors that can increase the vitreous rebleeding rate in these patients. OBJECTIVE: To carry out a retrospective review of the rate of vitreous rebleeding after vitrectomy or phacovitrectomy. METHOD: Retrospective, descriptive and comparative study of patients with a diagnosis of proliferative diabetic retinopathy with phacovitrectomy or vitrectomy procedure. Personal background data, type of surgical intervention and grade of the surgeon who carried out the procedure were obtained. RESULTS: 1227 files of diabetic patients with vitrectomy or phacovitrectomy were reviewed. 65% presented systemic arterial hypertension. The average glomerular filtration rate was 63.50 (±32.36) ml/min/1.73 m2 and glycosylated hemoglobin (HBA1C) of 8% (4.6 to 15%). In the comparison of variables, a significant difference in the rate of vitreous rebleeding was obtained comparing phacovitrectomy with vitrectomy. (p = 0.003), in the relationship between vitrectomy with vitreous rebleeding, an odds ratio of 1.44 was obtained. CONCLUSION: The results obtained show a lower rate of rebleeding in patients undergoing phacovitrectomy in patients with proliferative diabetic retinopathy.

Microbiota in mobile phones of medical ophthalmologists. / Microbiota en teléfonos móviles de médicos oftalmólogos.

OBJECTIVE: To determine the microbiota of mobile phones used during the ophthalmological consultation by medical personnel, patients, and family members. METHODS: An analysis was made on the mobile phones of the medical staff and of patients and/or family members in the area of clinical specialty. A survey was conducted to evaluate the pattern of use and disinfection of mobile phones. A smear sample was taken from the mobile phones. The specimens obtained were inoculated in culture media and incubated at 37°C for 24hours. Genus and species were identified in the positive cultures and the results obtained were analysed using descriptive statistics. RESULTS: An analysis was made on 71 mobile phones of medical personnel and 52 from patients and/or family members. The microorganisms isolated in the mobile phones of the ophthalmologists were: coagulase-negative staphylococci 50%, Staphylococcus aureus 32.4%, enterobacteria 4.2%, Actinomycetes 4.2%, and 9.8% were negative. On the other hand, in the phones of patients and relatives, the isolated microorganisms were Staphylococcus aureus 75%, coagulase-negative staphylococci 24%, and enterobacteria 1%. CONCLUSIONS: The results obtained show that mobile phones, both of the medical staff and of the patients and their relatives, contain bacteria considered pathogenic that could cause an infection. It is important to establish a routine practice of cleaning mobile phones and to make the population aware of hygiene habits, since they are responsible for the care of their eyes after consultation.

Relationship between blepharitis and components of the metabolic syndrome. / Relación entre blefaritis y componentes del síndrome metabólico.

OBJECTIVE: To determine the relationship between the components of the metabolic syndrome with the presence of blepharitis. METHODS: The study included 60 patients with a diagnosis of blepharitis and 30 control subjects. Anthropometric measurements and blood pressure were recorded, and peripheral venous blood samples were obtained under fasting conditions to determine the concentration of Glucose, Cholesterol, and Triglycerides. High-density lipoprotein cholesterol (HDL-C) was determined after precipitating lipoproteins containing apoB-100 with phosphotungstic acid/Mg2+. The concentration of low density lipoprotein cholesterol (LDL-C) was calculated using the Friedewald formula modified by DeLong. RESULTS: In the comparative analysis, statistically significant differences were found in the waist circumference (P=.0491), systolic blood pressure (P=.0149), glucose (P=.0045), total cholesterol (P=.0001), HDL-C (P=.0049), LDL-C (P=.0266), and triglycerides (P=.0059); while there was no significant differences in the BMI or the diastolic pressure. CONCLUSIONS: The results support the hypothesis that the metabolic syndrome could be considered a risk factor for the development of blepharitis, and its timely detection is essential to avoid future complications.

Resistance index measured by Doppler ultrasound as a predictor of graft function after kidney transplantation.

INTRODUCTION: Doppler ultrasound (US) has become the primary imaging technique for the evaluation of renal transplants. It provides information about the intrarenal resistance index (RI). A high RI is seen in every form of graft dysfunction. In this article, we review the utility of sonography, particularly the intrarenal RI measured early after renal transplant, as a predictor of acute and chronic clinical outcome in patients. RESULTS: RI is a valuable marker to determine graft function and related vascular complications. It reveals a strong correlation with serum creatinine levels measured days after transplant. Its elevation is typical for acute tubular necrosis and can be used to predict its duration. An RI >1 (absent end-diastolic flow) seen in the first weeks after transplant is associated with impaired renal graft recovery. In addition, it is an early predictor of chronic allograft nephropathy (even correlated with biopsy results), which will allow a change in therapy. CONCLUSIONS: RI measured serially in the early period after kidney transplantation is a valuable marker for determining renal graft function. It is also useful for demonstrating various types of graft dysfunction; however, it cannot differentiate between them. In recent studies, extrarenal factors in kidney transplantation (eg, recipient's age) may significantly influence RI in the recipient, demonstrating that RI depends on the vascular characteristics of the recipient and not on the graft itself.

Overexpression of peroxiredoxin 2 in pterygium. A proteomic approach.

Pterygium is one of the most frequent pathologies in ophthalmology, and is a benign, fibrovascular lesion originating from the bulbar conjunctiva. It is composed of an epithelium and highly vascular, subepithelial, loose connective tissue. The etiology of pterygium is not clearly understood; the most widely recognized originating factor is ultraviolet radiation. It has been proposed that pterygium and neoplasia have common features, raising the possibility that pterygium is a neoplastic-like growth disorder. In this study, proteomic analysis was performed to show that peroxiredoxin 2 is overexpressed in pterygia compared to healthy conjunctivas. Twelve pterygium specimens were obtained together with healthy conjunctival tissue from the same eyes. Total proteins of pterygia and healthy conjunctivas were analyzed in SDS-PAGE. This analysis showed protein bands expressed exclusively in pterygium samples at the range of 20-25 kDa. After this, 2D electrophoresis was performed for the separation of total proteins; differential spots expressed in pterygium were excised and sequenced. Mass spectrometry (MS) data were searched in the NCBInr and EST databases using the MASCOT program. The spot was identified as peroxiredoxin 2. Real-time PCR, western blot and immunohistochemistry showed that peroxiredoxin 2 was increased in pterygium compared to healthy conjunctiva. Although, these results suggest that overexpression of peroxiredoxin 2 in pterygium could protect the cell against oxidative stress-induced apoptosis, further studies are required to establish the functional role of peroxiredoxin 2 in pterygium to determine its role in peroxidation and apoptosis in this pathology.

Envases activos antioxidantes y su efecto sobrela calidad sensorial y los compuestos volátiles en leche entera deshidratada / Antioxidant active packaging effect whole milk powder sensorial quality and production of volatile compounds

El sabor de la leche está estrechamente relacionado con su composición, especialmente con su contenido graso. Factores como la luz, los materiales de envase y las condiciones de almacenamiento pueden favorecer la oxidación de la grasa y alterar las características sensoriales del producto. El presente estudio buscó evaluar el efecto de los envases activos multicapa con diferentes antioxidantes en su capa más interna: butilhidroxitolueno, butil hidroxianisol, alfa-tocoferol y una mezcla de butil hidroxianisol-alfa-tocoferol, sobrela calidad sensorial de la leche entera deshidratada. El entrenamiento de un panel sensorial permitió la evaluación del atributo de sabor oxidado en la leche y la correlación de estos resultados con la producción de pentanal, hexanal y heptanal, cuantificados mediante cromatografía gaseosa usando microextracción enfase sólida. Los análisis sensoriales revelaron cambios en las características de sabor oxidado en las muestras de leche. La correlación general de estos datos y las concentraciones de volátiles cuantificadas permitieron encontrar una correlación moderada pero significativa entre el sabor oxidado y los volátiles pentanal, hexanal y heptanal. En general, los envases activos con butil hidroxianisol-alfa-tocoferol y alfa-tocoferol obtuvieron una menor calificación en cuanto a su sabor oxidado y, en consecuencia, representan una alternativa viable para la conservación de las propiedades sensoriales de la leche.

Milk flavor is highly related with ITS components, especially with fat content. Factors such as light, packaging material and storage conditions can produce lipid oxidation and favor changes in the sensorial characteristics of product. The aim of this study was to evaluate the effect of active packaging with different antioxidants: butylated hydroxyanisole, butylated hydroxytoluene and alfa-tocopherol, on sensorial quality of whole milk powder. The panel members were trained to recognize the taste and smell of oxidized fat in milk and these results to be correlated with volatile compounds pentanal, heptanal and hexane quantified in milk samples using gas chromatography with solid phase microextraction. Sensorial tests showed changes in oxidized fat flavor in milk. The general correlation of these data and volatiles concentration allowed finding a moderate but significant correlation between oxidized fat flavor and thepentanal, hexanal and heptanal volatiles. In general, the active packaging with alfa-tocopherol-butylatedhidroxyanisole and alfa-tocopherol presented low score in oxidized fat flavor, representing a viable alternativefor the conservation of sensorial properties in milk during storage time.

Fluoroquinolone-resistant Streptococcus agalactiae isolates from Argentina.

Fluoroquinolone resistance is a growing problem that has only recently emerged in S. agalactiae. Between 2005-2007, WHONET--Argentina network evaluated levofloxacin susceptibility in 1128 clinical S. agalactiae isolates, 10 (0.9%) of which proved to be resistant. Nine of them had come from 5 hospitals (in Buenos Aires City and 4 Argentinean provinces) and recovered from urine (n=7) and vaginal screening cultures (n=2). Three strains were also resistant to macrolides, lincosamides and B streptogramins due to the ermA gene. All nine fluoroquinolone-resistant isolates bore the same two mutations, Ser79Phe in ParC and Ser81Leu in GyrA proteins. Genetic relationships were analyzed by Apal-PFGE and two clones were determined, A (n=6) and B (n=3). To our knowledge, these are the first fluoroquinolone-resistant S. agalactiae isolates detected in Latin America.

Cirugía pediátrica en régimen ambulatorio / No disponible

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Glucación no enzimática de la antitrombina. Implicaciones en el riesgo trombótico de pacientes con diabetes mellitus / Non-enzymatic antithrombin glycation. Association with atherothrombotic risk in diabetic patients

Introducción/objetivos. La glucación no enzimática incorpora azúcares a los residuos lisina y arginina de proteínas, lo que puede alterar su función. La glucación de la antitrombina, un potente anticoagulante natural, podría asociarse con el riesgo trombótico observado en situaciones de hiperglucemia, como la diabetes mellitus. Nuestro objetivo fue estudiar el efecto de la glucación de la antitrombina y determinar si es relevante en las complicaciones trombóticas de la diabetes mellitus. Métodos. 1. Glucación no enzimática in vitro de antitrombina plasmática y purificada con metilglioxal y glucosa. 2. Se analizó el efecto de diferentes compuestos sobre la glucación no enzimática de la antitrombina in vitro. 3. Estudio de 101 pacientes diabéticos. En todas las muestras se analizaron los valores antigénicos, la actividad anti-FXa, las características conformacionales y la afinidad a la heparina de la antitrombina. Resultados. La glucación no enzimática in vitro de la antitrombina con metilglioxal o glucosa no ocasiona modificaciones conformacionales significativas en la molécula, pero induce su transformación a una forma con baja afinidad por la heparina, que explica la pérdida significativa de su actividad (valor < 40% del basal). Este efecto se previene con heparina, aminoguanidina y catequina. Los pacientes diabéticos muestran menores valores antigénicos y funcionales de antitrombina (80%) que los sujetos controles, pero esta disminución no se correlaciona con la glucemia ni con los valores de hemoglobina glucosilada. Conclusiones. La glucación de residuos lisina y arginina localizados en el sitio de unión a la heparina de la antitrombina reduce significativamente su actividad anticoagulante, aunque puede ser protegida por la heparina, la aminoguanidina y la catequina. Sin embargo, la relevancia de la glucación de la antitrombina en pacientes diabéticos es apenas perceptible debido a la lenta acción glucante de la glucosa, y a la reducida vida media de la antitrombina (AU)

Introduction/Aims. Non-enzymatic glycation of proteins can impair their function by incorporating sugars into their lysine and arginine residues. Glycation of antithrombin, a powerful anticoagulant, might be associated with the thrombotic risk observed in hyperglycemic conditions such as diabetes mellitus. Our aim was to study the effects of antithrombin glycation and determine its significance in the thrombotic complications observed in diabetes. Methods. 1) In vitro study of non-enzymatic glycation of purified and plasma antithrombin by their incubation with methylglyoxal and glucose. 2) The effect of different compounds on the in vitro glycation of antithrombin was analyzed. 3) We studied 101 diabetic patients. Antigen levels, anti-FXa activity, conformational features and antithrombin affinity to heparin were determined. Results. In vitro non-enzymatic glycation of antithrombin with methylglyoxal or glucose caused no significant conformational change in the molecule, but induced the transformation to a low heparin-affinity form, which explains the significant loss of activity observed (< 40% of basal). This effect was prevented by heparin, aminoguanidine and catechin. Diabetic patients presented lower antigenic and antithrombin functional levels (80%) than controls. However, no correlation between activity or antigen levels of antithrombin and glycemia or glycosylated hemoglobin was found in diabetic patients. Conclusions. In vitro glycation of lysine and arginine residues located in the heparin-binding site of antithrombin significantly reduces its anticoagulant activity. Interestingly, heparin, aminoguanidine and catechin prevented this effect. However, the non-enzymatic glycation of antithrombin in diabetic patients seems to be mild, since the action of glucose is very slow and the half life of antithrombin in plasma is short (AU)

Bloqueo palmar. A propósito de un caso / Palm blockage. Case reporting

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Application of a new enzyme-linked immunosorbent assay for detection of total hepatitis C virus core antigen in blood donors.

Recent studies have shown that total hepatitis C virus (HCV) core antigen, both free and antibody bound, is an accurate indirect marker of viral replication that can be used in clinical practice. The aim of the present study was to evaluate the performance of a new total HCV core antigen enzyme-linked immunosorbent assay (ELISA) for detection and quantification of total core antigen in blood donors, testing positive for anti-HCV antibodies and for prospective low-risk population screening. A population comprising 257 samples, from blood donors detected reactive for anti-HCV antibodies [137 recombinant immunoblot assay (RIBA) positive and 120 RIBA indeterminate], were tested by using a new total HCV core antigen ELISA. HCV-RNA was quantified by using quantitative polymerase chain reaction (PCR) assays in all RIBA-positive samples and RIBA-indeterminate samples that were positive for the total core antigen. Specificity of the assay was studied in 1070 healthy blood donors negative for anti-HCV antibodies. Compared with quantitative PCR assays, the total HCV core antigen assay showed 97.37% sensitivity. The three HCV-RNA-positive samples, which tested negative for the total core antigen, had a low viral load (< 1.4 x 10(4) IU mL(-1)). All samples with more than 1.4 x 10(4) IU mL(-1) of viral RNA were positive for total core antigen, independent of the HCV genotype. Concentration of total core antigen correlated significantly with those of HCV-RNA (r = 0.614, P < 0.0001). Overall specificity in freshly collected blood donor specimens was 99.63%. Our data indicate that the total HCV core antigen ELISA has a sensitivity close to PCR assays in diagnosing HCV infection in blood donors with anti-HCV antibodies and shows an excellent specificity in volunteer donors. This assay, in combination with anti-HCV antibodies screening tests, could be an alternative to molecular assays for HCV infection screening in blood donors.

[The effect of propofol vs desflurane on recovery from anesthesia with remifentanil in outpatient surgery]. / Repercusión en la recuperación postanestésica de propofol frente a desflurano asociados a remifentanilo en cirugía ambulatoria.

OBJECTIVES: To compare the effect on parameters of postanesthetic recovery of propofol and desflurane administered with high doses of remifentanil for major outpatient surgery. PATIENTS AND METHODS: Seventy patients were randomly assigned to receive propofol (target concentration 1.5-2 microg/ml) or desflurane in perfusion (end expiratory concentration 0.5 MAC) during maintenance of anesthesia with remifentanil (0.25-1 microg/kg/min). The anesthetic agents were withdrawn after surgery. We recorded the times until eye opening, respiration, tracheal extubation, ability to cough, response to verbal orders and orientation. We also recorded the time until a score of 10 on the Aldrete recovery scale was attained, pain on a visual analog scale, sedation on the Ramsay scale, and instances of nausea or vomiting during the first 24 h after surgery. RESULTS: No statistically significant differences in patient characteristics, type of surgery or anesthesia were found. Times until early signs of postanesthetic recovery (eye opening, spontaneous breathing, tracheal extubation) were significantly less (p < 0.05) in the desflurane group. The groups were similar for all other parameters compared (times until ability to cough, respond to verbal orders, orientation and a score of 10 on the Aldrete scale). Duration of stay in the postanesthetic recovery unit, time in the day surgery ward and intensity of postoperative pain were also similar. The rate of postoperative nausea or vomiting was significantly lower in the propofol group. CONCLUSION: During anesthesia with remifentanil, the administration of desflurane is associated with better psychomotor recovery parameters than is propofol, but the rate of nausea and vomiting is higher with desflurane.

Repercusión en la recuperación postanestésica de propofol frente a desflurano asociados a remifentanilo en cirugía ambulatoria / The effect of propofol or desflurane on recovery from anesthesia with remifentanil for outpatient surgery

OBJETIVOS. Comparar la repercusión en parámetros de recuperación postanestésica de dos agentes anestésicos, propofol y desflurano, cuando se administran asociados a dosis elevadas de remifentanilo en cirugía mayor ambulatoria (CMA). PACIENTES Y MÉTODOS. Se incluyó a 70 pacientes para recibir de forma aleatoria propofol en perfusión (concentración TCI diana de 1,5-2 µg/ml) o desflurano (concentración teleinspiratoria de 0,5 CAM) durante el mantenimiento anestésico con remifentanilo (0,25-1 µg/kg/min). Al final de la intervención se suprimieron los agentes anestésicos y se registró el tiempo hasta la apertura de ojos, la ventilación espontánea, la extubación traqueal, la capacidad de toser, la respuesta a órdenes verbales y la orientación temporoespacial, así como el tiempo que tardaban en alcanzar una puntuación de 10 en la escala de recuperación de Aldrete, la intensidad del dolor postoperatorio mediante escala visual analógica, el grado de sedación según escala Ramsay y la incidencia de náuseas y vómitos postoperatorios durante las primeras 24 h. RESULTADOS. No existieron diferencias estadísticamente significativas entre ambos grupos respecto a las características demográficas y anestesicoquirúrgicas. Los parámetros de recuperación postanestésica tempranos (apertura de ojos, ventilación espontánea, extubación traqueal) fueron significativamente menores (p < 0,05) en el grupo desflurano, sin existir significación estadística en el resto de los parámetros comparados (capacidad de toser, respuesta a órdenes verbales, orientación temporoespacial y puntuación de 10 en la escala de Aldrete). Tampoco existieron diferencias con respecto a los tiempos de estancia en la unidad de recuperación postanestésica (URPA) y la sala de deambulación, ni en lo referente al dolor postoperatorio. En el grupo propofol la incidencia de náuseas y vómitos postoperatorios fue significativamente menor. CONCLUSIÓN. La anestesia basada en remifentanilo y desflurano proporciona unos parámetros de recuperación psicomotriz superiores al propofol, pero con una mayor incidencia de náuseas y vómitos (AU)

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Fatal upper and lower gastrointestinal cytomegalovirus disease following autologous peripheral blood stem cell transplantation.

Although the life-threatening cytomegalovirus (CMV) disease is a well known complication following allogeneic hematopoietic stem cell transplantation (HSCT), it has been considered infrequent after autologous peripheral blood stem cell transplantation (PBSCT). On the other hand, the massive involvement of the gastrointestinal (GI) tract as the primary site of fatal CMV disease is particularly rare after autologous PBSCT. We present the case of a woman who suffered from CMV disease after high-dose busulphan/melphalan/thiotepa (BuMelTT) and autologous PBSCT. The primary site of infection was the GI tract, which was extensively affected. During the fifth week post-transplant the patient started with epigastralgia, diarrhea, fever, GI bleeding, and thrombocytopenia, and she died on day +52. Another case of fatal CMV disease among the few patients treated with BuMelTT has been recently reported, which suggests that the immunodeficiency associated with that regimen can be as intense as that occurring after allogeneic BMT.

DSM-III-R co-morbidity in benzodiazepine dependence.

UNLABELLED: AIM, SAMPLE AND MEASURES: Co-morbidity has been shown to influence the clinical course of mental disorders. This paper describes DSM-III-R 1-month co-morbidity across axes I, II and III in a sample of 153 benzodiazepine dependents. All patients were evaluated through several in-depth clinical interviews across all five DSM-III-R axes. RESULTS: Extensive co-morbidity existed across three DSM-III-R axes. All patients had at least one diagnosis in axis I; 81 (52.9%) in axis II and 50 (32.7%) in axis III. The most prevalent diagnoses were: insomnia, anxiety disorders and affective disorders in axis I; obsessive-compulsive, histrionic and dependent personality disorders in axis II and rheumatological, neurological and cardiovascular disorders in axis III. CONCLUSIONS: There were no cases of benzodiazepine dependence appearing alone. There were associations within and between axes, suggesting potential predisposing factors and a sequential model for benzodiazepine dependence is proposed. The findings reinforce the need for exhaustive diagnostic evaluation of patients prior to prescribing benzodiazepine.

Benzodiazepine types in high versus therapeutic dose dependence.

Two types of benzodiazepine dependence have been described: high vs. therapeutic dose dependence. So far, no systematic research has been conducted regarding the frequency with which the various benzodiazepines are represented in one type or the other. In this study, 153 dependent patients using 14 different benzodiazepines were evaluated to assess the prevalence of their use among high vs. therapeutic dose dependents. Triazolam was the single drug most frequently used by high-dose dependents, followed by Lorazepam. No significant differences were found among benzodiazepines regarding their use by therapeutic dose dependents. Our data shows that pharmacokinetic and pharmacodynamic factors appear to be related to the frequency with which the different benzodiazepines are used by high and therapeutic dose dependents.