Probable interaction between acenocoumarol and levofloxacin: a case series.

WHAT IS KNOWN AND OBJECTIVE: To report five cases with a probable interaction between acenocoumarol and levofloxacin. CASE DESCRIPTION: In five patients on long-term acenocoumarol treatment who had had stable international normalized ratios for at least 6 months, sudden erratic changes in the values of these ratios were observed after 1.5-8 days of concomitant levofloxacin treatment with no other apparent cause. WHAT IS NEW AND CONCLUSIONS: Closer monitoring should be considered in patients with concomitant use of acenocoumarol and levofloxacin, especially elderly patients and those with renal dysfunction who seemed to suffer the interaction more severely.

Evolución de la adherencia al tratamiento antirretoviral del 2000 al 2008 / Evolution of antiretroviral treatment adherence from 2000 to 2008

Objetivos Evaluar la adherencia al tratamiento antirretroviral en la cohorte de pacientes VIH de nuestro hospital y ver su evolución a lo largo de 9 años; así como conocer el patrón individual de la adherencia con el tiempo. Métodos Estudio descriptivo de la evolución de la adherencia media anual y el porcentaje anual de pacientes con adherencias superiores al 95%, desde el 2000 al 2008. Se analizó el patrón individual de adherencia con el tiempo y se clasificó a los pacientes en adherentes consistentes, no adherentes consistentes y fluctuantes. Resultados En el análisis de 577 pacientes, la adherencia basal fue significativamente mayor en los pacientes naive respecto a los pretratados. La adherencia media anual aumentó ligeramente y se mantuvo en valores cercanos al 95%. Al igual que el porcentaje de pacientes con adherencia superior al 95%, que aumentó desde el 64% en el 2000 al 79% en 2008.En cuanto al patrón individual de adherencia con el tiempo, de los 468 pacientes analizados, la mayoría (59%) fueron adherentes consistentes, un 4% no adherente y el resto (37%) presentaban fluctuaciones en su adherencia. Conclusiones En nuestra cohorte los valores de adherencia global se mantienen con el tiempo e incluso presentan una tendencia positiva; resultado de una monitorización sistemática de la adherencia e implantación de estrategias dirigidas a mantener la adherencia (AU)

Objectives To evaluate antiretroviral treatment adherence in the HIV patient cohort of our hospital and observe their evolution over a 9-year period; also to determine the individual pattern of adherence over time. Methods Descriptive study of the evolution of average annual adherence and the annual percentage of adherent patients greater than 95% from 2000 to 2008. We analysed the individual pattern of adherence over time and patients were classified into consistently adherent, consistently non-adherent, and fluctuating. Results In the analysis of 577 patients, baseline adherence was significantly greater in naïve patients with respect to those who were pre-treated. Average annual adherence increased slightly and stayed at values around 95%. As with the percentage of patients with adherence greater than 95%, which increased from 64% in 2000 to 79% in 2008.In terms of the individual pattern of adherence over time, of the 468 patients analysed, the majority (59%) were consistently adherent, 4% non-adherent, and the rest (37%) fluctuated in their adherence. Conclusions In our cohort the overall adherence values maintained themselves over time and even show a positive trend, likely the result of systematic monitoring of adherence and implementation strategies to maintain adherence (AU)

[Evolution of antiretroviral treatment adherence from 2000 to 2008]. / Evolución de la adherencia al tratamiento antirretoviral del 2000 al 2008.

OBJECTIVES: To evaluate antiretroviral treatment adherence in the HIV patient cohort of our hospital and observe their evolution over a 9-year period; also to determine the individual pattern of adherence over time. METHODS: Descriptive study of the evolution of average annual adherence and the annual percentage of adherent patients greater than 95% from 2000 to 2008. We analysed the individual pattern of adherence over time and patients were classified into consistently adherent, consistently non-adherent, and fluctuating. RESULTS: In the analysis of 577 patients, baseline adherence was significantly greater in naïve patients with respect to those who were pre-treated. Average annual adherence increased slightly and stayed at values around 95%. As with the percentage of patients with adherence greater than 95%, which increased from 64% in 2000 to 79% in 2008. In terms of the individual pattern of adherence over time, of the 468 patients analysed, the majority (59%) were consistently adherent, 4% non-adherent, and the rest (37%) fluctuated in their adherence. CONCLUSIONS: In our cohort the overall adherence values maintained themselves over time and even show a positive trend, likely the result of systematic monitoring of adherence and implementation strategies to maintain adherence.

[Prospective assessment of drug interactions in hospitalized patients using a computer programme]. / Evaluación prospectiva de interacciones entre medicamentos en pacientes ingresados mediante una aplicación informática.

OBJECTIVE: To describe the implementation, functioning and results of a prospective automated system monitoring clinically relevant interactions in hospitalised patients in a 400-bed hospital for the period between 1 January 2005 and 31 March 2006. METHOD: We created a computer programme in Access(R) 97 that checks, twice daily, the drug treatments of all of the patients admitted to the hospital in order to search for the 198 pairs of drugs previously selected from: a validated tertiary source (Hansten PD, Horn JR. Hansten and Horn's Drug Interactions Analysis and Management. St. Louis, MO: Facts and Comparisons; 2001 and updates), most relevant primary sources, expert opinions and alerts from the Spanish Agency of Medicines and Health Products. The clinical pharmacist will assess the drug-drug interaction (DDI) taking into account the timeline sequence, dose, administration route, management opportunities, patient diagnosis, clinical relevance, etc. If necessary, the doctor is contacted by phone and/or letter to inform him/her of the type of interaction, the mechanism and possible management. The programme files the following variables every day: interaction, sex, age, service, number of drugs, pharmaceutical intervention and doctor response. RESULTS: Clinically relevant drug interactions were detected in 3% of patients during their stay in hospital. These patients were an average of 10 years older and received an average of four drugs more than other patients. A total of 538 interactions were detected in 15 months. Forty-three of 198 possible DDls appeared at some time. The pharmacist intervened on 126 (23%) occasions. The doctor accepted the recommendation on at least 66 (52%) occasions. Fourteen drugs were responsible for 91% of the interactions reported. CONCLUSIONS: The patients with interactions are older and receive more drugs. The prior intervention of the pharmacist eliminated 77% of unnecessary alerts.

[Simplification to lamivudine, zidovudine, and abacavir therapy: impact on adherence, clinical outcome, and economic issues]. / Simplificación con lamivudina, zidovudina y abacavir: repercusión sobre la adhrencia, resultados clínicos e impacto económico.

OBJECTIVES: To analyze the influence on adherence and clinical outcome of the replacement of a previous antiretroviral therapy to a simplified approach using zidovudine, lamivudine, and abacavir (Trizivir) and to assess its economic impact. METHODS: A retrospective study of 75 pretreated, HIV-infected adult patients who received Trizivir from May 2001 to December 2002. Adherence was assessed by dispensation records or medication counting, CD4 lymphocyte counts, and viral load before and six months after medication change was analyzed; finally, the cost of each therapy was assessed in order to calculate the economic impact of medication change. RESULTS: Mean adherence significantly increased a 2.5% after medication change; 16 more patients reached optimal adherence, with an NNT (number of patients requiring therapy change in order to obtain one more adherent) of 4.7. The number of patients with undetectable viral load remained almost similar, and mean CD4 cell counts stayed above 500 cells/mm3 in both periods of time. A great variability in incremental costs was seen, due to the varying costs of the previous treatments, and the influence of five intensification therapies using Trizivir. However, when only simplification regimens were analyzed such variability was reduced, and even became favorable in selected cases. CONCLUSIONS: Changing to a simplification therapy using Trizivir resulted in improved adherence, similar clinical outcomes, and a varying economic impact depending on previous antiretroviral therapy costs.

A cost-analysis of suspected adverse drug reactions in a hospital emergency ward.

The main objective of this study was to analyse the minimum direct cost to the Public Health System (PHS) of diagnosing and treating those patients attended to in the emergency ward (EW) for suspected adverse drug reaction (ADR). The cases were collected during March 1995 in the emergency ward of a 900-bed tertiary teaching hospital that covers 900,000 inhabitants. ADR was considered according to the WHO definition. The following EW costs were used: EW physician visit 78.5 ecus (1 ecu=156 pesetas), thorax or abdomen radiograph 21.5 ecus, computerized tomography 112.7 ecus, endoscopy 48 ecus, specialist physician visit 62 ecus. Three types of laboratory costs were considered: block of biochemical tests 16 ecus, biochemical tests with blood count 22.5 ecus, and biochemical tests with blood count and coagulation study 41.6 ecus. Pharmacotherapy of the ADR and changes in patient's usual drug therapy due to ADR were estimated. For patients admitted in the hospital, a per day cost of 391 ecus was considered. A mean ADR cost per organ or system affected (cutaneous, metabolic, gastrointestinal, nervous) was computed. The main conclusion of this study is that ADR, apart from inflicting damage on the patients, also incur PHS costs. The quantity of 42,732 ecus during the month of March, in a single hospital, can seem small when compared with the cost of some diseases such as AIDS or ischemic heart disease. But remembering that about 40% of all ADR attended to in hospitals is avoidable, a decrease of 40% could produce an annual saving of 205,216 ecus to the hospital, which is twice the annual budget of the Pharmacovigilance Centre of the Basque Country. Pharmacovigilance centres should include cost analysis of ADR among their objectives, to provide health systems managers with enough information to implement those measures that will result in a better utilization of the scarce resources of the Public Health System.

The extent of sodium and water administration associated with i.v. drug infusions in a surgical unit.

OBJECTIVE: To quantify sodium and water administered to surgical patients but not actually prescribed by the physician. METHODS: Computerized medication records of 1208 surgical patients who were operated on in 1992 were analysed retrospectively. Only prescriptions for intravenous (i.v.) drugs and fluids were selected. RESULTS: Thirteen of 143 i.v. drugs made up 68.3% of prescriptions for i.v. drugs. Patients received a median of three i.v. drugs daily. Patients were on i.v. therapy for a mean of 4.6 +/- 6.0 days (range 1-140, median 3 days). On 24% of patient-days, patients received more than 100 mEq of sodium which was not consciously prescribed, and on 20.4% of patient-days they had an extra daily intake of 750 ml of water or more. One fourth of the total sodium and more than 15% of fluid administered to patients was in the form of NaCl 0.9%, used as a vehicle for i.v. drugs. CONCLUSIONS: There is a considerable amount of sodium and water administered to patients without a specific prescription. The promotion of knowledge about the correct administration of i.v. drugs is an important task for the clinical pharmacist. If this is achieved, it will allow for an optimal administration of drugs as well as the prevention of possible side effects from an intended sodium and water administration.