Bipolar disorder and medication: adherence, patients' knowledge and serum monitoring of lithium carbonate.

OBJECTIVES: this study featured patients with affective bipolar disorder who were making use of lithium and received care at an outpatient care center located in a country town in the state of Sao Paulo in 2009; it assessed the adherence and knowledge of these patients in relation to the medication prescribed to them and verified the proportion of blood tests performed per year in the service, for each individual, to measure lithium levels in the blood. METHOD: descriptive study with quantitative approach, involving 36 participants. Structured interviews and review of medical records were used for data collection and descriptive statistics for data analysis. RESULTS: difficulties in reporting the dosage of the medication prescribed and a high rate of non-adherence were identified among the participants. None of the participants in the study was submitted to two tests a year to measure lithium levels in the blood, which is the minimum proportion of tests recommended by the literature for maintenance treatment using lithium carbonate. CONCLUSION: this study highlights the critical factors for the promotion of patients' safety in monitoring lithium drug therapy.

Bipolar disorder and medication: adherence, patients' knowledge and serum monitoring of lithium carbonate / Transtorno bipolar e medicamentos: adesão, conhecimento dos pacientes e monitorização sérica do carbonato de lítio / Trastorno bipolar y medicamentos: adhesión, conocimiento de los pacientes y monitorización sérica del carbonato de litio

OBJECTIVES: this study featured patients with affective bipolar disorder who were making use of lithium and received care at an outpatient care center located in a country town in the state of Sao Paulo in 2009; it assessed the adherence and knowledge of these patients in relation to the medication prescribed to them and verified the proportion of blood tests performed per year in the service, for each individual, to measure lithium levels in the blood. METHOD: descriptive study with quantitative approach, involving 36 participants. Structured interviews and review of medical records were used for data collection and descriptive statistics for data analysis. RESULTS: difficulties in reporting the dosage of the medication prescribed and a high rate of non-adherence were identified among the participants. None of the participants in the study was submitted to two tests a year to measure lithium levels in the blood, which is the minimum proportion of tests recommended by the literature for maintenance treatment using lithium carbonate. CONCLUSION: this study highlights the critical factors for the promotion of patients' safety in monitoring lithium drug therapy. .

OBJETIVOS: este estudo teve como objetivo caracterizar pacientes com transtorno afetivo bipolar, em uso de lítio, atendidos no ano 2009 em um serviço ambulatorial do interior de São Paulo, Brasil; avaliar a adesão e conhecimento dos mesmos sobre medicamentos prescritos e verificar a proporção de litemias/ano realizadas, no serviço, para cada indivíduo. MÉTODO: trata-se de estudo descritivo, com abordagem quantitativa, do qual participaram 36 pessoas. Foram utilizadas entrevistas estruturadas e revisão de prontuários para coleta de dados e estatística descritiva para análise dos mesmos. RESULTADOS: entre os participantes, foram identificadas dificuldades em relatar a dose dos fármacos prescritos e alta taxa de não adesão. Em nenhum participante do estudo foi atingida a proporção de duas litemias/ano, que representa a quantidade mínima de litemias preconizada pela literatura para o tratamento de manutenção com carbonato de lítio. CONSIDERAÇÕES FINAIS: este estudo aponta fatores críticos na promoção da segurança do paciente no seguimento da terapêutica medicamentosa com lítio. .

OBJETIVOS: este estudio caracterizó pacientes con trastorno afectivo bipolar, tratadas con litio, atendidos en el año de 2009 en un servicio de ambulatorio del interior del estado de Sao Paulo, en Brasil; evaluó la adhesión y conocimiento de los mismos sobre medicamentos prescritos y verificó la proporción de litemias/año realizadas, en el servicio, para cada individuo. MÉTODO: se trata de estudio descriptivo, con abordaje cuantitativo, del cual participaron 36 personas. Fueron utilizadas entrevistas estructuradas y revisión de fichas para recolección de datos y estadística descriptiva para análisis de los mismos. RESULTADOS: entre los participantes, fueron identificadas dificultades en relatar la dosis de los fármacos prescritos y una alta tasa de no adhesión. En ningún participante del estudio fue alcanzada la proporción de dos litemias/año, que representa la cantidad mínima de litemias preconizada por la literatura para el tratamiento de mantenimiento con carbonato de litio. CONCLUSIÓN: este estudio apunta factores críticos para la promoción de la seguridad del paciente en el seguimiento de la terapéutica medicamentosa con litio. .

Bioequivalence of two lithium formulations in healthy volunteers.

OBJECTIVE: The purpose of this study was to compare the maximum exposure and extent of bioavailability of two lithium carbonate (CAS 554-13-2) containing 300 mg tablet formulations (test and reference) for oral administration. METHOD: This bioequivalence study was conducted in a 2-period crossover design with a washout phase of 7 days. Plasma samples were obtained by blood sampling over 72 h in each period. Twenty-four healthy volunteers of both genders participated in the trial. Samples were analyzed by a flame atomic absorption spectrometer. Resulting Li+ concentrations were used for determination of the pharmacokinetic parameters AUC(last), AUC(inf) and C(max). RESULTS: 90 % confidence intervals for AUC(last), AUC(inf) and C(max) were 96.81-107.44%, 98.44-109.54% and 98.60-111.33%, respectively. CONCLUSION: All 90% and 95% confidence intervals were inside the limits defined by the FDA Guidance for Industry (80%-125%) and thus stated that test and reference formulation may be accepted as bioequivalent, with regard to both, maximum exposure and extent of bioavailability.

Pharmacokinetics of lithium in healthy volunteers after exposure to high altitude.

INTRODUCTION: Exposure of the human body to high altitude causes a number of physiological changes. In previous studies, we observed that these changes may alter the pharmacokinetics of drugs. The number of erythrocytes/mm3 increases both, after acute exposure to high altitude (HA), i.e. within 12 - 24 h after reaching high altitude (H), as well as in chronic exposure (HC) (> 10 months) to H. Also binding of drugs to biologic material may change with exposure to HA and/or HC. OBJECTIVE: Since lithium is transported into and out of erythrocytes and binds strongly to erythrocytes, but is not plasma protein-bound, we selected this drug as candidate for the present study. SUBJECTS, MATERIAL AND METHODS: Lithium carbonate 300 mg were administered orally to young healthy volunteers. One group residing at low altitude (Santiago, Chile, 600 m, group L), these same volunteers after 15 hours of exposure to high altitude (4,360 m, group HA), and volunteers living at high altitude for at least 10 months (group HC). RESULTS: We found a significant increase of both hematocrit and red blood cell count (RBC) after exposure to H, both, acute or chronic. Elimination half-life increased 64.1% in group HA and 111.4% in group HC in comparison to group L. We also found an increase in volume of distribution: + 18.9% in group HA, and + 35.8% in group HC when measured in plasma, and + 16.9% in group HA and + 18.8% in group HC when measured in whole blood. Lithium uptake by the erythrocytes increases: the value of 36.7 +/- 22.7% in Group L rose to 54.8 +/- 21.1% and to 54.6 +/- 24.2% in groups HA and HC, respectively. Total clearance decreases at high altitude, though the differences were significant only in group HC (37%). CONCLUSION: Results indicate that exposure to H produces alterations in the pharmacokinetics of lithium and that these variations may be clinically relevant.

Evaluation of the in vitro and in vivo performance of two sustained-release lithium carbonate matrix tablets. Effect of different diets on the bioavailability.

Two sustained-release (SR) lithium carbonate (Li) matrix tablets, which use a hydrophilic (HP) matrix of hydroxypropylmethylcellulose (Methocel 4K MP) and a lipid (L) matrix of hydrogenated castor oil (Cutina HR) as sustaining agents, have been studied. In vitro performance through dissolution tests in different media was established. The L and HP formulations were affected by the composition of the dissolution media, and liberation was complete in 8 hr using a variable-pH medium that simulates the gastrointestinal (Gl) pH. Liberation was better described by the diffusional model of the square root of time for the L matrix and by zero-order kinetics for the HP matrix. Absolute bioavailability (BA) and food-induced changes on BA of both formulations were studied. The in vivo study design was a 4 x 4 Latin square involving 12 subjects who received two tablets of a 300-mg dose of SR formulations while fasting or with a standardized normal, high-fat, or high-fat/high-protein meal. The results for both formulations showed no differences in the disposition parameters and mean residence time when the tablets were administered with any type of diet. Changes in rate of absorption were found when both types of tablets were administered with any class of diet. The analysis of the ratio Cmax/AUC (area under the curve) evidenced that changes in Cmax were attributable to a higher rate of absorption for the HP matrix and to a higher amount absorbed for the L matrix. In the last, high-fat and high-fat/high-protein diets produced higher AUCs than under fasting condition. The SR Li tablets formulated with hydrogenated castor oil were affected more by high-fat food, probably because of the increase of pancreatic and biliary secretions promoted by the meal, which would affect the matrix itself. The HP matrix was also affected, but to a lesser extent. The magnitude of the change in Cmax observed with this matrix probably is not important from a clinical point of view. Absolute BA was very low for the lipid matrix; in addition, since it is more seriously affected by food, probably it is not a good choice for a drug such as lithium. The in vivo behavior of the HP matrix makes it advisable to invest in efforts to achieve increased BA. Comparing in vitro and in vivo results, the focus should be achieving sustained, but complete, in vitro liberation in not more than 3 hr, with simulation of the transit time through the stomach and small bowel since lithium ion is only absorbed to this point.

Técnica para la administración controlada de dosis iniciales útiles de carbonato de litio / Technique for controlled administration of useful initial dosage of lithium carbonate

Este trabajo es un estudio preliminar usando una simplificación de la técnica original desarrollada por Cooper para la administración controlada de dosis iniciales de carbonato de litio. El nivel plasmático de litio fue medido entre 13 pacientes depresivos mayores, 24 horas después de una dosis única de 600 mg de Carbonato de Litio. De acuerdo a los valores obtenido los pacientes fueron divididos en concentradores "altos", "medianos" y "bajos" (niveles plasmáticos de 0,21 a más de 0,30 meq/lt, 0.11 a 0.20 y menos de 0.11 meq/lt respectivamente), recibiendo el grupo "alto" 600, el grupo "mediano" 900 y el grupo "bajo" 1.200 mg de carbonato de litio diario. Al séptimo dia del protocolo, el nivel plasmático del litio tuvo un promedio entre 0.40 y 0.60 meq/lt en los 3 grupos